(If n is omitted, the exit status is that of the last command executed. ) 格式:$? 上一个命令的退出码。 格式:trap "commands" EXIT 退出时执行commands指定的命令。( A trap on EXIT is executed before the shell terminates.) 退出码(exit status,或exit code)的约定: 0表示成功(Zero - Success...
(If n is omitted, the exit status is that of the last command executed. ) 格式:$? 上一个命令的退出码。 格式:trap "commands" EXIT 退出时执行commands指定的命令。( A trap on EXIT is executed before the shell terminates.) 退出码(exit status,或exit code)的约定: 0表示成功(Zero - Success...
管道里传对象这件事情同时违背了 KISS 原则和高内聚低耦合原则，让不同的命令从内部数据结构上都全部耦...
Exit Codes #!/bin/bash exit 0 # Exit the script successfully exit 1 # Exit the script unsuccessfully echo $? # Print the last exit code Conditional Statements Boolean Operators $foo - Is true !$foo - Is false Numeric Operators -eq - Equals -ne - Not equals -gt - Greater than -ge ...
2. 如要在last中找出root的信息 last | grep 'root' 注:last可以直接打印出登录者留下的姓名 反向输出只需要加上-v 3.也可grep与cut共同使用,这样便只能取出每行的第一列 如:last | grep 'root' |cut -d ' ' -f 1 4.这个命令可以把取出的东西给于颜色 ...
last | tr '[a-z]' '[A-Z]'#这行命令可以将原数据小写字母替换成大写字母,也就是tr不使用-d的时候并且使用了SET2的情况下,就会使用SET2替换SET1,且字符逐个对应 echo ${PATH} | tr -d ':'#这行命令仅用于测试,实际应用中不会出现 a='aaa'; echo ${a} | tr -s 'a'#创建一个变量a,并使...
# Version: 42, Last Modified: 2018/03/21 10:09 Feb 24, 2018 new bash cheatsheet Feb 24, 2018 4 5 6 7 # https://github.com/skywind3000/awesome-cheatsheets ### Feb 24, 2018 update bash.sh Feb 24, 2018 8 ### Mar 3, 2018...
maxdepth 1 -type f | wc -l)echo -n "Directory: $item, Files: $num_files"fi# 显示权限信息和最后修改时间permissions=$(ls -l "$item" | awk '{print $1}')last_modified=$(ls -l "$item" | awk '{print $6, $7}')echo ", Permissions: $permissions, Last Modified: $last_modified...
The TEST-COMMAND list is executed, and if its return status is zero, the CONSEQUENT-COMMANDS list is executed. The return status is the exit status of the last command executed, or zero if no condition tested true. Testing and Branching;elif; ...
$!" # 返回最近一个后台命令的进程 ID sleep 1 echo "the last parameter of the previous command: \$_ $_" # 上一个命令的最后一个参数, 比如这里是1 选项参数传递 getopts 是一个用于解析命令行选项和参数的内置命令, 语法为 getopts optstring name optstring 是一个字符串, 定义脚本可以接收的选项, ...