linux ds指令,Linux 指令不完全介绍（待续）

╰+攻爆jí腚メ 2023-01-21 11:15 7阅读 0赞

定位

pwd show current location

ls list all files in the current level

ls -R shows every file and directory in the current level, then everything in each sub-directory

ls -F -R prints a / after the name of every directory and a \* after the name of every runnable program.

cd + new path move to the new path

.. the directory above the one you're currently in

If you are in /home/repl/seasonal, then cd .. moves you up to /home/repl

. the current directory

cd . has no effect to the current location

~ path of the user's home directory

ls ~ will list the contents of your home directory

cd ~ give you home location

if you are in /home/repl/seasonal, then cd ~/../. will take you to /home/

复制文件

cp make a copy of the original file

cp original.txt duplicate.txt creates a copy of original.txt called duplicate.txt. If there already was a file called duplicate.txt, it is overwritten.

cp seasonal/autumn.csv seasonal/winter.csv backup copies all of the files into backup directory.

移动或重命名文件

move the files to another path

mv autumn.csv winter.csv moves the files autumn.csv and winter.csv from the current working directory up one level to its parent directory

rename files ( overwriting if file name are the same)

mv course.txt old-course.txt then course.txt in the current working directory is "moved" to the file old-course.txt

删除文件、路径

rm : remove as many as files you want by specifying their paths

rmdir: remove directories

mkdir :create a new directory

查看文件内容

cat print out the file content on to the screen

If file is large, then use less :

When you less a file, one page is displayed at a time; you can press spacebar to page down or type q to quit.

If you give less the names of several files, you can type :n (colon and a lower-case 'n') to move to the next file, :p to go back to the previous one, or :q to quit.

head if not specified, print out the first 10 lines of a file

head -n 100 display the first 100 lines

tail -n if not specify n , print out the last 10 lines of a file

tail -n +\[Num\] output the starting with \[Num\]

cut -f + columns no. -d , file name: select columns

cut -f 2-5,8 -d , values.csv which means select -f columns 2 through 5 and columns 8 , using (-d) comma , as the separator

cut doesn't understand quoted strings

在文件中寻找匹配

grep: selects lines according to what they contain

grep bicuspid seasonal/winter.csv prints lines from winter.csv that contain "bicuspid"

flag

usage

\-c

print a count of matching lines rather than the lines themselves

\-h

do not print the names of files when searching multiple files

\-i

ignore case (e.g., treat "Regression" and "regression" as matches)

\-l

print the names of files that contain matches, not the matches

\-n

print line numbers for matching lines

\-v

invert the match, i.e., only show lines that don't match

对文件进行单词计数

wc : word count

if print the number of

flag

characters

\-c

words

\-w

lines

\-l

排序

sort: puts data in order

flag

meaning

\-n

sort numerically

\-r

reverse the order of its output

\-b

ignore leading blanks

\-f

tells it to fold case (i.e., be case-insensitive)

去重

uniq: only removes adjacent duplicated lines

uniq -c: display unique lines with a count of how often each occurs

重复上之前的指令 ！

history: print a list of commands you have run recently

! command\_name: re-run the most recent use of that command

! 55 : re-run the 55th command in your history

储存指令的结果 >

>: store output symbol

head's output is put in a new file called top.csv has the following two ways

head -n 5 seasonal/summer.csv > top.csv

> top.csv head -n 5 seasonal/summer.csv

多个指令的Pipline |

|: The pipe symbol, which tells the shell to use the output of the command on the left as the input to the command on the right.

head -n 5 seasonal/summer.csv | tail -n 3:

通配符

Wildcards

match

example

match zero or more characters

s\* will match spring.csv or summer.csv

matches a single character

201?.txt will match 2017.txt or 2018.txt

\[...\]

matches any one of the characters inside the square brackets

201\[78\].txt matches 2017.txt or 2018.txt

\{...\}

matches any of the comma-separated patterns inside the curly brackets

\{\*.txt, \*.csv\} matches any file whose name ends with .txt or .csv

变量

Type

Def

environment variables

those that are available all the time, in UPPER CASE

shell variables

assign by = , called by adding $ to it

常见环境变量

Variable Name

Purpose

HOME

User's home directory

PWD

Present working directory

SHELL

Which shell program is being used

USER

User's ID

To get a complete list (which is quite long), you can type set in the shell.

打印变量的值

echo prints its arguments

echo hello gives hello

echo $USER gives repl ( the value of environment variable value )

创建新文件

touch : create a new file

修改文件

vi filename

after the file is opened, the default mode is command mode

command

Purpose

delete a line

copy a line

paste a line

undo

move to the head of file

move to the tail of file

/\*\*

search for \*\*

执行文件

可以用的指令有： source , sh , bash, ./ ， fork , source, exec

各个指令的区别

记录之前历史指令

Run history.

Pipe its output to tail -n 10 (or however many recent steps you want to save).

Redirect that to a file called something like figure-5.history.

储存指令在新文件以便重复执行

Use touch to create a file to store commands, called it dates.sh

Use sh to run the commands in dates.sh

Store output in new file dates.out

touch dates.sh

vi dates.sh

add cut -d , -f 1 seasonal/\*.csv to dates.sh

then click ^O + ^X to save and exit the file

sh dates.sh > dates.out

自定义参数

$@ all of the command-line parameters given to the script

$1,$2,... specific command-line parameters

unique-lines.sh contains sort $@ | uniq,

when you run:

sh unique-lines.sh seasonal/summer.csv

then:

the shell replaces $@ with seasonal/summer.csv and processes one file.

column.sh contains cut -d , -f $2 $1

and then run it using:

sh column.sh seasonal/autumn.csv 1

then:

the shell replaces $1 with seasonal/autumn.csv,

$2 with 1

自定义函数

for loop

for ...variable... in ...list.../wildcards ; do ...body... ; done

Input

for filetype in gif jpg png; do echo $filetype; done

it produces

gif jpg png

Input

for f in seasonal/\*.csv; do echo $f ; head -n 2 $f | tail -n 1; done

it produces

seasonal/autumn.csv 2017-01-05,canine seasonal/spring.csv 2017-01-25,wisdom

定义函数

function\_name () \{

list of commands

hello() \{

echo "Hello $1"

Call function, set param as "world" and output\_

hello world

自动补全

tab auto-completion of the file name, if multiple files exist with the same first letter, press tab twice

获得帮助

man see the manual of a command

man, help, info 区别

linux ds指令,Linux 指令不完全介绍（待续）

发表评论取消回复

还没有评论，来说两句吧...

相关阅读

相关【Linux】Linux基本指令

相关 Linux kill指令和killall指令

相关 linux ds指令,Linux 指令不完全介绍（待续）

相关 Linux指令

相关 Linux 基本指令

相关 Linux指令--alias

相关 Linux基本指令

相关 Linux 之实用指令-查找指令

相关 Linux 之使用指令-帮助指令

相关【Linux】Linux基本指令