The if in a Bash script is a shell keyword that is used to test conditions based on the exit status of a test command. An exit status of zero, and only zero, is a success, i.e. a condition that is true. Any other exit status is a failure, i.e. a condition that is false. ...
echo"Input argument exists." Here the “-z” option is used with the “test” command to check if the input argument is an empty string or not. The script will output an error message and exit with a status code of 1 if the input argument is an empty string. Otherwise, the script ...
[root@c7-server ~]#cateven_odd_if.sh#!/bin/bashif[ $# -ne1];thenecho"You must input just one argument."exit1fivar=$[$(id-u $1)%2]if[ $var -eq0];thenecho"The UID of $1 is even."elseecho"The UID of $1 is odd."fi 编写一个脚本,接收两个文件名作为参数,返回文件的行数...
progname=${0##*/} ## Get the name of the script without its path ## Default values verbose=0 filename= ## List of options the program will accept; ## those options that take arguments are followed by a colon optstring=f:v ## The loop calls getopts until there are no more options...
/bin/bashif id zwl &> /dev/null; then echo "User zwl exists."fi[root@c7-server ~]# bash test.sh User zwl exists. 1. 2. 双分支if语句 if TEST; then CMD-TRUEelse CMD-FALSEfi 1. 2. 3. 为真执行CMD-TRUE,为假执行CMD-FALSE。
*args是函数使用者可以发送任意数量非键值对的参数传给这个函数，*args在接收参数后，将返回值以元组...
cp myscript 然后再插入自己的函数。 让我们再看两个例子: 二进制到十进制的转换 脚本b2d 将二进制数 (比如 1101) 转换为相应的十进制数。这也是一个用expr命令进行数学运算的例子: #!/bin/sh # vim: set sw=4 ts=4 et: help() { cat < ...
First this program will print “Start program”, then the IF statement will check if the conditional expression[[ $1 -eq 4 ]]is true. It will only be true if you provide4as the first argument to the script. If the conditional expression if true then it will execute the code in betwee...
‘-f’ option is used in the following script to test the file existence. Create a file named, ‘file_exist.sh’ and add the following code. Here, the filename will pass from the command line. #!/bin/bash filename=$1 if [ -f "$filename" ]; then echo "File exists" else echo...
Shell script - trying to validate if a git tag exists in a git repository in an if/else statement 我正在为zend应用程序创建部署脚本。 仅当我想验证存储库中是否存在标签以将标签强制加入团队时,该笔录几乎完成了。 目前,我有以下代码: 1234567891011121314151617 # Fist update the repo to make sure ...