linux c 内存操作函数简介

喜欢ヅ旅行 2023-01-19 04:58 163阅读 0赞

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      &nbsp; 
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   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp（比较内存内容）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp，strcasecmp，strcmp，strcoll，strncmp，strncasecmp</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
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   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">int bcmp ( const void *s1,const void * s2,int n);</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp()用来比较s1和s2所指的内存区间前n个字节，若参数n为0，则返回0。</span></span></td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若参数s1 和s2 所指的内存内容都完全相同则返回0 值，否则返回非零值。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">建议使用memcmp()取代。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">参考memcmp()。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy（拷贝内存内容）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memccpy，memcpy，memmove，strcpy，ctrncpy</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void bcopy ( const void *src,void *dest ,int n);</span></span></td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy()与memcpy()一样都是用来拷贝src所指的内存内容前n个字节到dest所指的地址，不过参数src与dest在传给函数时是相反的位置。</span></span></td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;">&nbsp;</td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">建议使用memcpy()取代</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char dest[30]=”string(a)”;<br> char src[30]=”string/0string”;<br> int i;<br> bcopy(src,dest,30);/* src指针放在前*/<br> printf(bcopy(): “)<br> for(i=0;i&lt;30;i++)<br> printf(“%c”,dest[i]);<br> memcpy(dest src,30); /*dest指针放在钱*/<br> printf(‘/nmemcpy() : “);<br> for(i=0;i&lt;30;i++)<br> printf(“%c”,dest[i]);</span></span></td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
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   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy() : string string<br> memcpy() :string sring</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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      &nbsp; 
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   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">bzero（将一段内存内容全清为零）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memset，swab</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void bzero(void *s,int n)；</span></span></td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bzero()会将参数s所指的内存区域前n个字节，全部设为零值。相当于调用memset((void*)s,0,size_tn);</span></span></td> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;">&nbsp;</td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">建议使用memset取代</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">参考memset()。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">index（查找字符串中第一个出现的指定字符）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">rindex，srechr，strrchr</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * index( const char *s, int c);</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index()用来找出参数s字符串中第一个出现的参数c地址，然后将该字符出现的地址返回。字符串结束字符(NULL)也视为字符串一部分。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果找到指定的字符则返回该字符所在地址，否则返回0。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *s =”0123456789012345678901234567890”;<br> char *p;<br> p =index(s,’5’);<br> printf(%s/n”,p);<br> }</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">5.68E+25</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
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      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">memccpy（拷贝内存内容）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memcpy，memmove，strcpy，strncpy</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void * memccpy(void *dest, const void * src, int c,size_t n);</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memccpy()用来拷贝src所指的内存内容前n个字节到dest所指的地址上。与memcpy()不同的是，memccpy()会在复制时检查参数c是否出现，若是则返回dest中值为c的下一个字节地址。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回指向dest中值为c的下一个字节指针。返回值为0表示在src所指内存前n个字节中没有值为c的字节。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char a[]="string[a]";<br> char b[]="string(b)";<br> memccpy(a,b,'B',sizeof(b));<br> printf("memccpy():%s/n",a);<br> }</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memccpy():string(b)</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">memchr（在某一内存范围中查找一特定字符）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，rindex，strchr，strpbrk，strrchr，strsep，strspn，strstr</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void * memchr(const void *s,int c,size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memchr()从头开始搜寻s所指的内存内容前n个字节，直到发现第一个值为c的字节，则返回指向该字节的指针。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果找到指定的字节则返回该字节的指针，否则返回0。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> main()<br> { <br> char *s="0123456789012345678901234567890";<br> char *p;<br> p=memchr(s,'5',10);<br> printf("%s/n",p);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">5.68E+25</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">memcmp（比较内存内容）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp，strcasecmp，strcmp，strcoll，strncmp，strncasecmp</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">int memcmp (const void *s1,const void *s2,size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memcmp()用来比较s1和s2所指的内存区间前n个字符。字符串大小的比较是以ASCII码表上的顺序来决定，次顺序亦为字符的值。memcmp()首先将s1第一个字符值减去s2第一个字符的值，若差为0则再继续比较下个字符，若差值不为0则将差值返回。例如，字符串"Ac"和"ba"比较则会返回字符'A'(65)和'b'(98)的差值(－33)。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若参数s1和s2所指的内存内容都完全相同则返回0值。s1若大于s2则返回大于0的值。s1若小于s2则返回小于0的值。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *a ="aBcDeF";<br> char *b="AbCdEf";<br> char *c="aacdef";<br> char *d="aBcDeF";<br> printf("memcmp(a,b):%d/n",memcmp((void*)a,(void*) b,6));<br> printf("memcmp(a,c):%d/n",memcmp((void*)a,(void*) c,6));<br> printf("memcmp(a,d):%d/n",memcmp((void*)a,(void*) d,6));</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memcmp(a,b):1 /*字符串a&gt;字符串b，返回1*/<br> memcmp(a,c):-1 /* 字符串a&lt;字符串c,返回－1*/<br> memcmp(a,d):0 /*字符串a＝字符串d，返回0*/</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">memcpy（拷贝内存内容）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memccpy，memcpy，memmove，strcpy，strncpy</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void * memcpy (void * dest ,const void *src, size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memcpy()用来拷贝src所指的内存内容前n个字节到dest所指的内存地址上。与strcpy()不同的是，memcpy()会完整的复制n个字节，不会因为遇到字符串结束'/0'而结束。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回指向dest的指针。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">指针src和dest所指的内存区域不可重叠。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char a[30]="string (a)";<br> char b[30]="string/0string";<br> int i;<br> strcpy(a,b);<br> printf("strcpy():");<br> for(i=0;i&lt;30;i++)<br> printf("%c",a[i]);<br> memcpy(a,b,30);<br> printf("/nmemcpy() :");<br> for(i=0;i&lt;30;i++)<br> printf("%c",a[i]);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcpy() : string a )<br> memcpy() : string string</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">memmove（拷贝内存内容）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memccpy，memcpy，strcpy，strncpy</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void * memmove(void *dest,const void *src,size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memmove()与memcpy()一样都是用来拷贝src所指的内存内容前n个字节到dest所指的地址上。不同的是，当src和dest所指的内存区域重叠时，memmove()仍然可以正确的处理，不过执行效率上会比使用memcpy()略慢些。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回指向dest的指针。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">指针src和dest所指的内存区域可以重叠。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">参考memcpy()。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">memset（将一段内存空间填入某值）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bzero，swab</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">void * memset (void *s ,int c, size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">memset()会将参数s所指的内存区域前n个字节以参数c填入，然后返回指向s的指针。在编写程序时，若需要将某一数组作初始化，memset()会相当方便。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回指向s的指针。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">参数c虽声明为int， 但必须是unsigned char ，所以范围在0到255之间。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> main()<br> { <br> char s[30];<br> memset (s,'A',sizeof(s));<br> s[30]='/0';<br> printf("%s/n",s);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">rindex（查找字符串中最后一个出现的指定字符）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，memchr，strchr，strrchr</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * rindex( const char *s,int c);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">rindex()用来找出参数s字符串中最后一个出现的参数c地址，然后将该字符出现的地址返回。字符串结束字符(NULL)也视为字符串一部分。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果找到指定的字符则返回该字符所在的地址，否则返回0。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> mian()<br> { <br> char *s ="0123456789012345678901234567890";<br> char *p;<br> p=rindex(s,'5');<br> printf("%s/n",p);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">567890</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strcasecmp（忽略大小写比较字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp，memcmp，strcmp，strcoll，strncmp</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">int strcasecmp (const char *s1, const char *s2);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcasecmp()用来比较参数s1和s2字符串，比较时会自动忽略大小写的差异。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若参数s1和s2字符串相同则返回0。s1长度大于s2长度则返回大于0 的值，s1 长度若小于s2 长度则返回小于0的值。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> main()<br> { <br> char *a="aBcDeF";<br> char *b="AbCdEf";<br> if(!strcasecmp(a,b))<br> printf("%s=%s/n",a,b);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">aBcDeF=AbCdEf</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strcat（连接两字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memccpy，memcpy，strcpy，strncpy</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char *strcat (char *dest,const char *src);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcat()会将参数src字符串拷贝到参数dest所指的字符串尾。第一个参数dest要有足够的空间来容纳要拷贝的字符串。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回参数dest的字符串起始地址</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h.&gt;<br> main()<br> { <br> char a[30]="string(1)";<br> char b[]="string(2)";<br> printf("before strcat() : %s/n",a);<br> printf("after strcat() : %s/n",strcat(a,b));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">before strcat () : string(1)<br> after strcat () : string(1)string(2)</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strchr（查找字符串中第一个出现的指定字符）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，memchr，rinex，strbrk，strsep，strspn，strstr，strtok</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * strchr (const char *s,int c);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strchr()用来找出参数s字符串中第一个出现的参数c地址，然后将该字符出现的地址返回。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果找到指定的字符则返回该字符所在地址，否则返回0。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *s=0123456789012345678901234567890”;<br> char *p;<br> p=strchr(s,'5');<br> printf("%s/n",p);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">5.68E+25</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strcmp（比较字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp，memcmp，strcasecmp，strncasecmp，strcoll</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">int strcmp(const char *s1,const char *s2);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcmp()用来比较参数s1和s2字符串。字符串大小的比较是以ASCII 码表上的顺序来决定，此顺序亦为字符的值。strcmp()首先将s1第一个字符值减去s2第一个字符值，若差值为0则再继续比较下个字符，若差值不为0则将差值返回。例如字符串"Ac"和"ba"比较则会返回字符"A"(65)和'b'(98)的差值(－33)。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若参数s1和s2字符串相同则返回0。s1若大于s2则返回大于0的值。s1若小于s2则返回小于0 的值。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *a="aBcDeF";<br> char *b="AbCdEf";<br> char *c="aacdef";<br> char *d="aBcDeF";<br> printf("strcmp(a,b) : %d/n",strcmp(a,b));<br> printf("strcmp(a,c) : %d/n",strcmp(a,c));<br> printf("strcmp(a,d) : %d/n",strcmp(a,d));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcmp(a,b) : 32<br> strcmp(a,c) :-31<br> strcmp(a,d) : 0</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strcoll（采用目前区域的字符排列次序来比较字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcmp，bcmp，memcmp，strcasecmp，strncasecmp</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">int strcoll( const char *s1, const char *s2);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcoll()会依环境变量LC_COLLATE所指定的文字排列次序来比较s1和s2 字符串。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若参数s1和s2字符串相同则返回0。s1若大于s2则返回大于0的值。s1若小于s2则返回小于0 的值。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若LC_COLLATE为"POSIX"或"C"，则strcoll()与strcmp()作用完全相同。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">参考strcmp()。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strcpy（拷贝字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memcpy，memccpy，memmove</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char *strcpy(char *dest,const char *src);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcpy()会将参数src字符串拷贝至参数dest所指的地址。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回参数dest的字符串起始地址。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">附加说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果参数dest所指的内存空间不够大，可能会造成缓冲溢出(buffer Overflow)的错误情况，在编写程序时请特别留意，或者用strncpy()来取代。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char a[30]="string(1)";<br> char b[]="string(2)";<br> printf("before strcpy() :%s/n",a);<br> printf("after strcpy() :%s/n",strcpy(a,b));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">before strcpy() :string(1)<br> after strcpy() :string(2)</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strcspn（返回字符串中连续不含指定字符串内容的字符数）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strspn</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#inclued&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">size_t strcspn ( const char *s,const char * reject);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcspn()从参数s字符串的开头计算连续的字符，而这些字符都完全不在参数reject 所指的字符串中。简单地说，若strcspn()返回的数值为n，则代表字符串s开头连续有n个字符都不含字符串reject内的字符。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回字符串s开头连续不含字符串reject内的字符数目。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> main()<br> { <br> char *str="Linux was first developed for 386/486-based pcs.";<br> printf("%d/n",strcspn(str," "));<br> printf("%d/n",strcspn(str,"/-"));<br> printf("%d/n",strcspn(str,"1234567890"));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">5 /*只计算到“ ”的出现，所以返回“Linux”的长度*/<br> 33 /*计算到出现“/”或“－”，所以返回到“6”的长度*/<br> 30 /* 计算到出现数字字符为止，所以返回“3”出现前的长度*/</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strdup（复制字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">calloc，malloc，realloc，free</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * strdup( const char *s);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strdup()会先用maolloc()配置与参数s字符串相同的空间大小，然后将参数s字符串的内容复制到该内存地址，然后把该地址返回。该地址最后可以利用free()来释放。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回一字符串指针，该指针指向复制后的新字符串地址。若返回NULL表示内存不足。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char a[]="strdup";<br> char *b;<br> b=strdup(a);<br> printf("b[ ]=/"%s/"/n",b);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">b[ ]="strdup"</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strlen（返回字符串长度）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;">&nbsp;</td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">size_t strlen (const char *s);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strlen()用来计算指定的字符串s的长度，不包括结束字符"/0"。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回字符串s的字符数。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">/*取得字符串str的长度*/<br> #include&lt;string.h&gt;<br> main()<br> { <br> char *str = "12345678";<br> printf("str length = %d/n", strlen(str));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">str length = 8</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strncasecmp（忽略大小写比较字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcmp，memcmp，strcmp，strcoll，strncmp</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">int strncasecmp(const char *s1,const char *s2,size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strncasecmp()用来比较参数s1和s2字符串前n个字符，比较时会自动忽略大小写的差异。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">若参数s1和s2 字符串相同则返回0。s1 若大于s2则返回大于0的值，s1若小于s2则返回小于0 的值。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *a="aBcDeF";<br> char *b="AbCdEf";<br> if(!strncasecmp(a,b))<br> printf("%s =%s/n",a,b);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">aBcDef=AbCdEf</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strncat（连接两字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memccpy，memecpy，strcpy，strncpy</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#inclue &lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * strncat(char *dest,const char *src,size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strncat()会将参数src字符串拷贝n个字符到参数dest所指的字符串尾。第一个参数dest要有足够的空间来容纳要拷贝的字符串。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回参数dest的字符串起始地址。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> main()<br> { <br> char a[30]="string(1)";<br> char b[]="string(2)";<br> printf("before strnact() :%s/n", a);<br> printf("after strncat() :%s/n", strncat(a,b,6));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">before strnact() : string(1)<br> after strncat() : string(1) string</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strncpy（拷贝字符串）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">bcopy，memccpy，memcpy，memmove</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * strncpy(char *dest,const char *src,size_t n);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strncpy()会将参数src字符串拷贝前n个字符至参数dest所指的地址。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回参数dest的字符串起始地址。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#inclue &lt;string.h&gt;<br> main()<br> { <br> char a[30]="string(1)";<br> char b[]="string(2)";<br> printf("before strncpy() : %s/n",a);<br> printf("after strncpy() : %s/n",strncpy(a,b,6));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">before strncpy() : string(1)<br> after strncpy() : string(1)</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strpbrk（查找字符串中第一个出现的指定字符）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，memchr，rindex，strpbrk，strsep，strspn，strstr，strtok</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;include.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char *strpbrk(const char *s,const char *accept);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strpbrk()用来找出参数s 字符串中最先出现存在参数accept 字符串中的任意字符。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果找到指定的字符则返回该字符所在地址，否则返回0。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include &lt;string.h&gt;<br> main()<br> { <br> char *s="0123456789012345678901234567890";<br> char *p;<br> p=strpbrk(s,"a1 839"); /*1会最先在s字符串中找到*/<br> printf("%s/n",p);<br> p=strprk(s,"4398");/*3 会最先在s 字符串中找到*/<br> printf("%s/n",p);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">1.23E+29</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strrchr（查找字符串中最后出现的指定字符）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，memchr，rindex，strpbrk，strsep，strspn，strstr，strtok</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * strrchr(const char *s, int c);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strrchr()用来找出参数s字符串中最后一个出现的参数c地址，然后将该字符出现的地址返回。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">如果找到指定的字符则返回该字符所在地址，否则返回0。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *s="0123456789012345678901234567890";<br> char *p;<br> p=strrchr(s,'5');<br> printf("%s/n",p);<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">567890</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strspn（返回字符串中连续不含指定字符串内容的字符数）</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strcspn，strchr，strpbrk，strsep，strstr</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">size_t strspn (const char *s,const char * accept);</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strspn()从参数s 字符串的开头计算连续的字符，而这些字符都完全是accept 所指字符串中的字符。简单的说，若strspn()返回的数值为n，则代表字符串s 开头连续有n 个字符都是属于字符串accept内的字符。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回字符串s开头连续包含字符串accept内的字符数目。</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char *str="Linux was first developed for 386/486-based PCs.";<br> char *t1="abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";<br> printf("%d/n",strspn(str,t1));<br> }</span></span></td> 
  </tr> 
  <tr> 
   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">5 /*计算大小写字母。不包含“ ”，所以返回Linux的长度。*/</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
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   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strstr（在一字符串中查找指定的字符串）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，memchr，rindex，strchr，strpbrk，strsep，strspn，strtok</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char *strstr(const char *haystack,const char *needle);</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
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   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strstr()会从字符串haystack 中搜寻字符串needle，并将第一次出现的地址返回。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回指定字符串第一次出现的地址，否则返回0。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char * s="012345678901234567890123456789";<br> char *p;<br> p= strstr(s,"901");<br> printf("%s/n",p);<br> }</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">9.01E+21</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"><span style="color:#333333;"><span style="color:#4f4f4f;">　</span></span> 
    <div style="margin-left:0px;"> 
     <br> 
     <span style="color:#333333;"><span style="color:#4f4f4f;"><a rel="nofollow"></a></span></span> 
    </div> </td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;">
      &nbsp; 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><br><span style="color:#333333;"><span style="color:#4f4f4f;">strtok（分割字符串）</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">相关函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">index，memchr，rindex，strpbrk，strsep，strspn，strstr</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">表头文件</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">定义函数</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">char * strtok(char *s,const char *delim);</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">函数说明</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">strtok()用来将字符串分割成一个个片段。参数s指向欲分割的字符串，参数delim则为分割字符串，当strtok()在参数s的字符串中发现到参数delim的分割字符时则会将该字符改为/0 字符。在第一次调用时，strtok()必需给予参数s字符串，往后的调用则将参数s设置成NULL。每次调用成功则返回下一个分割后的字符串指针。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">返回值</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">返回下一个分割后的字符串指针，如果已无从分割则返回NULL。</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">范例</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">#include&lt;string.h&gt;<br> main()<br> { <br> char s[]="ab-cd : ef;gh :i-jkl;mnop;qrs-tu: vwx-y;z";<br> char *delim="-: ";<br> char *p;<br> printf("%s ";strtok(s,delim));<br> while((p=strtok(NULL,delim)))printf("%s ",p);<br> printf("/n");<br> }</span></span></td> 
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   <td style="border-color:#dddddd;text-align:left;width:118px;"> 
    <div style="margin-left:0px;"> 
     <span style="color:#333333;"><span style="color:#4f4f4f;">执行</span></span> 
    </div> </td> 
   <td style="border-color:#dddddd;text-align:left;width:694px;"><span style="color:#333333;"><span style="color:#4f4f4f;">ab cd ef;gh i jkl;mnop;qrs tu vwx y;z /*－与:字符已经被/0 字符取代*/</span></span></td> 
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