linux必知必会-xargs命令xargs命令

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我是靠谱客的博主玩命缘分，最近开发中收集的这篇文章主要介绍linux必知必会-xargs命令xargs命令，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

xargs命令

为啥必须要学会xargs命令？

主要原因是xargs的作用太大了，应用十分广泛，以下是平时工作中经常用到的一部分:
- 读取文件并重新格式化
- 配合wc统计文件行数
- 查找文件后批量删除文件
- 批量关闭进程
- 批量修改文件的权限
- 批量解压文件
- 其它用法可使用xargs --help深入学习

[root@dev127 myb]# xargs --help
Usage: xargs [OPTION]... COMMAND INITIAL-ARGS...
Run COMMAND with arguments INITIAL-ARGS and more arguments read from input.

Mandatory arguments to long options are mandatory for short options too.
Non-mandatory arguments are indicated by [square brackets]
  -0, --null                   Items are separated by a null, not whitespace.使用
                               Disables quote and backslash processing
  -a, --arg-file=FILE          Read arguments from FILE, not standard input
  -d, --delimiter=CHARACTER    Input items are separated by CHARACTER, not by
                               blank space. Disables quote and backslash
                               processing
  -E END                       If END occurs as a line of input, the rest of
                               the input is ignored.
  -e [END], --eof[=END]        Equivalent to -E END if END is specified.
                               Otherwise, there is no end-of-file string
  --help                       Print a summary of the options to xargs.
  -I R                         same as --replace=R (R must be specified)
  -i,--replace=[R]             Replace R in initial arguments with names
                               read from standard input. If R is
                               unspecified, assume {}
  -L,-l, --max-lines=MAX-LINES Use at most MAX-LINES nonblank input lines per
                               command line
  -l                           Use at most one nonblank input line per
                               command line
  -n, --max-args=MAX-ARGS      Use at most MAX-ARGS arguments per command
                               line
  -P, --max-procs=MAX-PROCS    Run up to max-procs processes at a time
  -p, --interactive            Prompt before running commands
  --process-slot-var=VAR       Set environment variable VAR in child
                               processes
  -r, --no-run-if-empty        If there are no arguments, run no command.使用
                               If this option is not given, COMMAND will be
                               run at least once.
  -s, --max-chars=MAX-CHARS    Limit commands to MAX-CHARS at most
  --show-limits                Show limits on command-line length.
  -t, --verbose                Print commands before executing them
  --version                    Print the version number
  -x, --exit                   Exit if the size (see -s) is exceeded

Report bugs to <bug-findutils@gnu.org>.

xargs的使用

读取文件并重新格式化

例如下面的命令把一个4行4个字母格式化为1行了:

$ cat c.txt 
a
b
c
d

$ cat c.txt |xargs
a b c d

格式化为每行2项:

$ cat c.txt |xargs -n2
a b
c d

指定分割符号-d:

$ echo "a;b;c;d" | xargs -d ";"
a b c d

统计文件行数

$ wc ./* -l
   40 ./b.txt
    4 ./c.txt
  130 ./tmp.txt
  174 total

等价于:

$ wc ./* -l
   40 ./b.txt
    4 ./c.txt
  130 ./tmp.txt
  174 total

查找并删除文件

查找a目录下的.txt结尾的文件并删除不询问

$ find ./a -name "*.txt" | xargs -i rm {}

查找a目录下的.log结尾的文件并询问是否删除:

$  find ./a -name "*.log" | xargs -p -i rm {}
rm ./a/lobby.20220118.log ?...y
rm ./a/lobby.20220118-2.log ?...y
rm ./a/lobby.20220117-3.log ?...y
rm ./a/lobby.20220117-2.log ?...y
rm ./a/lobby.20220118-3.log ?...y
rm ./a/lobby.20220118-1.log ?...y
rm ./a/lobby.20220115.log ?...y
rm ./a/lobby.20220117-5.log ?...y
rm ./a/lobby.20220117-1.log ?...y
rm ./a/lobby.20220116.log ?...y
rm ./a/lobby.20220117.log ?...y
rm ./a/lobby.20220117-4.log ?...y
rm ./a/lobby.20220117-6.log ?...y

批量修改文件的权限

批量修改当前目录下的lua文件把权限为755的改为644:

find ./ -name "*.lua" -perm 755 | xargs chmod 644

批量关闭进程

批量杀掉包含关键字"chrome"的进程:

ps -ef | grep chrome | grep "grep" -v |xargs kill
或
ps -ef | grep chrome | ag "ag" -v |xargs kill

批量解压文件

$ls gate.20220117*.log.gz  | xargs -i tar -xzvf {}
data/log/server/gate/gate.20220117-1.log
data/log/server/gate/gate.20220117-2.log
data/log/server/gate/gate.20220117-3.log
data/log/server/gate/gate.20220117-4.log
data/log/server/gate/gate.20220117.log