linux 常用的11种文本查看工具日志查看分析

爱被打了一巴掌 2022-10-09 14:24 460阅读 0赞

## Intro ##

首先，一定不止11种，这里只是列举我所知的11种。

## List ##

<table> 
 <thead> 
  <tr> 
   <th align="left">command</th> 
   <th align="left">whatis xxx</th> 
   <th align="left">功能</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td align="left">head</td> 
   <td align="left">output the first part of files</td> 
   <td align="left">输出文件的头部内容</td> 
  </tr> 
  <tr> 
   <td align="left">tail</td> 
   <td align="left">output the last part of files</td> 
   <td align="left">输出文件的结尾内容</td> 
  </tr> 
  <tr> 
   <td align="left">cat</td> 
   <td align="left">concatenate files and print on the standard output</td> 
   <td align="left">连接文件，打印到标准输出流</td> 
  </tr> 
  <tr> 
   <td align="left">tac</td> 
   <td align="left">concatenate and print files in reverse</td> 
   <td align="left">连接文件，并倒序打印文件</td> 
  </tr> 
  <tr> 
   <td align="left">more</td> 
   <td align="left">file perusal filter for crt viewing</td> 
   <td align="left">文件浏览过滤器</td> 
  </tr> 
  <tr> 
   <td align="left">less</td> 
   <td align="left">opposite of more</td> 
   <td align="left">more的对应</td> 
  </tr> 
  <tr> 
   <td align="left">grep</td> 
   <td align="left">print lines matching a pattern</td> 
   <td align="left">打印匹配指定模式的行</td> 
  </tr> 
  <tr> 
   <td align="left">awk</td> 
   <td align="left">pattern scanning and text processing language</td> 
   <td align="left">模式扫描和文本处理语言</td> 
  </tr> 
  <tr> 
   <td align="left">sed</td> 
   <td align="left">stream editor for filtering and transforming text</td> 
   <td align="left">可用于过滤、传输文件的流编辑器</td> 
  </tr> 
  <tr> 
   <td align="left">vi</td> 
   <td align="left">Vi IMproved, a programmer’s text editor</td> 
   <td align="left">Vi改进版，一款程序员的文本编辑器</td> 
  </tr> 
  <tr> 
   <td align="left">nano</td> 
   <td align="left">Nano’s ANOther editor, an enhanced free Pico clone</td> 
   <td align="left">另一款文本编辑器</td> 
  </tr> 
 </tbody> 
</table>

分类记忆(按照最基本的**文本内容查看**之外，特别的功能)：

*  文本编辑需求(查看/搜索/编辑) `vi nano sed`
 *  大文本(部分加载) `less/more`
 *  文件合并 `cat/tac`
 *  文件头尾 `tail/head`
 *  linux文本处理三剑客 `grep sed awk` 其中`awk`甚至可以说是一小巧的语言，他有自己的命令语法，功能强且使用复杂。

## 适用场景 ##

*  某个日志文件还在增量写入，这时想“滚动”查看日志文件尾部新增的内容 `tail -f <nohup.out>`
 *  grep配合正则表达式对文本内容过滤
 *  vi 查看/修改各类日志/配置等文本文件。

甚至在已安装某些vi插件库的前提下，vi可以再`不解压压缩包/jar包时，进入压缩包中查看文件列表，读写其中某个文件的内容`

*  less/more查看大的日志文件(GB级别)

通过`man less`查看该命令的使用手册`manual`

Description
    Less is a program similar to more (1), but it has many more features.  
    Less does not have to read the entire input file before starting, 
    so with large input files it starts up faster than text editors like vi (1).  
    Less uses termcap (or terminfo on some systems), so it can run on a variety of terminals.  
    There is even limited support for hardcopy terminals.  
    (On a hardcopy terminal, lines which should be printed at the top of the screen are prefixed with a caret.)
    
    Commands are based on both more and vi.  
    Commands may be preceded by a decimal number, called N  in  the  descriptions  below.
    The number is used by some commands, as indicated.

信息点：  
1. less类似于常用的more，但特性/功能更多。  
2. 数据加载策略是部分加载，所以相较于vi，`更适用于大文件`  
3. 该命令的实现基于 more 和 vi。  
最简单的使用 `less <filename>`  
详细参数可以通过linux的帮助命令：[断网 命令行查询某个命令的详细信息 使用手册 参数详情 7种方式][_ _ _ 7]查看。

[_ _ _ 7]: https://wuyujin.blog.csdn.net/article/details/118206459