HOST="google.com"ping -c1$HOST # -c is usedforcount, it will send the request, number of times mentionedRETURN_CODE=$? # 最后运行的命令的结束代码(返回值)即执行上一个指令的返回值if["$RETURN_CODE"-eq"0"]thenecho"$HOST reachable"elseecho"$H...
The statementCALLER=`basename $0`is used to get the name of the script being run. In that way, you do not need to hard-code the script name in the script. Thus, when you make a copy of the script, it will take less work to adapt the newly derived script. The statementTEMP=`getop...
Return value is returned by using "return xxx". xxx is in [0,255], saved in $?. Return a string is invalid. If no "return xxx" in function, return the result of last command. Two ways to get the return value: foo i=$? foo() { echo 3 } i=`foo` Use keyword "local" to ...
The “comparison.sh” is executed successfully. That’s why terminals show zero as the return code. Similarly, you will get non-zero as the successful execution of the script. For example, if you use the Ls instead of the ls command in the script, you may get the non-zero as the ret...
While ShellCheck is mostly intended for interactive use, it can easily be added to builds or test suites. It makes canonical use of exit codes, so you can just add ashellcheckcommand as part of the process. For example, in a Makefile: ...
shell的return(没写return的函数, return的值就被称为status code? ) 类似python等语言的return, echo对标print Common options (GNU Coreutils) ‘-d file’ ‘-f file’ 这俩没有相互包含关系 好多参数 -n 判断是否非空 ${#var}will get the length of $var The test command doesn't understand ==,...
bash: arpspoof: command not found 执行arpspoof命令报命令找不到,如下 bash: arpspoof: command not found 执行:apt-get install arpspoof -y,报错如下图 执行:apt-get install dsniff -y 注:没有叫arpspoof的包,想要使用arpspoof命令,必须安装dsniff包... ...
Get the location 代码语言:javascript 代码运行次数:0 运行 AI代码解释 script_dir=$(cd"$(dirname "${BASH_SOURCE[0]}")"&>/dev/null&&pwd-P) 这行代码尽其所能定义脚本的位置目录,然后我们对其进行cd配置。为什么? 通常,我们的脚本在相对于脚本位置的路径上运行,复制文件并执行命令,假设脚本目录也是一个...
值并发生重复赋值时,bash会覆盖该键。这 允许我们有效地删除数组重复。 CAVEAT:需要bash4+ 示例功能: remove_array_dups() { # Usage: remove_array_dups "array" declare -A tmp_array for i in "$@"; do [[ $i ]] && IFS=" " tmp_array["${i:- }"]=1 ...
Syntax: return [n] where n is a number. If n is not supplied, then it will return the exit code of the last command run. Though, the possible value range for the return builtin is limited to the least significant 8 bits which are 0 to 255. Any number above 255 will just return ...