The statements[ -z "$X" ]andecho "The environment variable X is not set."andusageare used to test if the string is null (-z) and if so, then perform the echo statement saying that it is not set and invoke the "usage" function discussed below. If your script does not use flags,...
functionhelp {param=$1#外部传参#echo "Usage : link-bin Target_Path Bin_FileName" # 不应该有多个echoret="echo string as return【$param】"#通过echo标准输出返回值echo$ret} echo_get=$(help param_abc)#通过$()调用执行函数并接收返回echo"Get the function echo_get: $echo_get" 该方法是捕获...
举例来说,脚本是script.sh,有 Shebang 行的时候,可以直接调用执行。 $ ./script.sh 上面例子中,script.sh是脚本文件名。脚本通常使用.sh后缀名,不过这不是必需的。 如果没有 Shebang 行,就只能手动将脚本传给解释器来执行。 $ /bin/sh ./script.sh # 或者 $ bash ./script.sh 执行权限和路径 前面说过...
# Clear screen on script exit. trap 'printf \\e[2J\\e[H\\e[m' EXIT 忽略终端中断(CTRL + C,SIGINT) trap '' INT 对窗口调整大小做出反应 # Call a function on window resize. trap 'code_here' SIGWINCH 在每个命令之前做点什么 trap 'code_here' DEBUG 当shell函数或源文件完成执行时执行某些...
echo "Usage $0 {one|two|three}" ;; esac 另外,function也是拥有内置变量的。它的内置变量与shell script很类似,函数名称代表$0.而后续接的变量也是以$1,$2……来代替的。 循环: 除了if...then...fi这种条件判断式之外,循环可能就是程序当中最重要的一环了。循环可以不断的执行某个程序段落,直到用户设置...
Try to provide "usage" feedback Try to provide a "silent" running mode Provide one function to terminate the script when there are errors When possible, provide functions that do a single task well Capture the output of each script, while watching the output being produced ...
# 位置参数调用, 假设在终端输入 bash bash_tutorial.sh 1 2 3echo"current script name: \$0$0"# 当前脚本名称echo"incoming parameters: \$1$1\$2$2\$3$3"# 访问传入的参数echo"the number of parameters: \$#$#"# 传入的参数数量echo"all parameters: \$@$@"# 每个参数作为独立字符串echo"all ...
echo "Usage: $0 [-u]" echo echo "-u: Update the script" echo echo "If run by root: datafiles in /Library/OpenPorts are created, but no output." echo "If run by any other user: output is displayed based on those datafiles." ...
Write a Bash script with a variable declared inside a function. Try to access the variable outside the function and observe the result. Code: #!/bin/bash# Shebang line: Indicates the path to the shell interpreter (in this case, bash)# Define a functionmy_function(){localinside_variable=...
2.1 脚本调试 2.2 脚本执行方法 2.3 管道符号 | 2.4 交互式硬件设备 2.5 重定向操作 2.6 变量 (1) 变量的赋值与引用 ① 变量赋值 ② 变量引用 (2) 变量类型 ① 自定义变量...)bash 后可跟绝对路径和相对路径,脚本无需执行权限 source 执行( source /PATH/to/script.sh )source 后可跟绝对路径和相对路径...