犀利的原文,可以在这里查看: http://stackoverflow.com/questions/592620/how-to-check-if-a-program-exists-from-a-bash-script/677212#677212
When trying to understand the working of a function like if-else in a shell script, it is good to start things simple. Here, we initialize two variables a and b, then use the if-else function to check if the two variables are equal. The bash script should look as follows for this t...
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 ...
写法2:我们创建一个用户,将该用户在/etc/passwd里面的信息删除,当看到这里的时候我们似乎看出了点特点,这就是嵌套if语句的特点:之前学到如果if语句行的命令的退出状态为非0,所有的命令都会被跳过,但是会输出else和elif后面的语句,这就相当于是否则判断语句;但if语句行如果为0时,则后面的语句也不会再执行(如第一...
If ~/.bash_profile is not found, bash attempts toread this script. ~/.profile If neither ~/.bash_profile nor ~/.bash_loginis found, bash attempts to read this file. This is thedefault in Debian-based distributions, such as Ubuntu. 文件 内容 /etc/profile 应用于所有用户的全局配置脚本。
In a script, you would typically use it in an if statement. To negate and check if the folder or file doesnotexist, use either "!" or "-not", and remember to enclose the Test-Path statement in parentheses. Also remember that if the path or folder name contains a space, you need to...
Hi All, I have the following script that checks to see if a Site exists in a SPO list and either updates or adds the item to the list. For some...
[root@web-server01~/script]#vimlogin.sh #!/bin/bash #CheckFiletochange. #Byauthorrivers2021-9-27 USERS="hbs" whiletrue do echo"TheTimeis`date+%F-%T`" sleep10 NUM=`who|grep"$USERS"|wc-l` if[[$NUM-ge1]];then echo"The$USERSislogininsystem." ...
if [ -d "/some/directory" ]; then log_message "Directory exists." else log_message "Directory does not exist." && exit 1 fi log_message "Script finished." 这个脚本将日志写入文件并打印在终端,帮助你记录脚本的执行情况。 3.3 定时任务和Cron 结合cron,你可以定期运行Shell脚本,实现自动化。例如,...
If you can enter commands into the shell, you can write shell scripts (also known as Bourne shell scripts). A shell script is a series of commands written in a ...