In this bash script example, we first set the filename, the size_threshold variable and then check if any file exists with the given name using the -e option. If it exists, we use the wc command to get the file size in bytes and store it in the file_size variable. Next, we check...
In programming, it is essential to check if a variable is “set” or “not set,” which means you have to check if a bash script variable has a value or not. This check helps for effective data validation. However, there’s no built-in function for checking empty variables in bash sc...
Example-2: Check the variable is set or unset using parameter substitute Create a bash file named “check_var2.sh” and add the following script. Here, a string value is assigned to the variable, $str before checking the variable is set or unset. The ‘if’ condition will return true a...
When you check an archive with the t mode, verify that everything is in a rational directory structure; that is, all file pathnames in the archive should start with the same directory. If you’re unsure, create a temporary directory, change to it, and then extract. (You can always use...
温故知新,Linux命令知多少,学习Bash Shell 缩写大全 pwd:print work directory打印当前目录 显示出当前工作目录的绝对路径 ps:process status(进程状态,类似于windows的任务管理器) 常用参数:-auxf ps -auxf 显示进程状态 df:disk free其功能是显示磁盘可用空间数目信息及空间结点信息。换句话说,就是报告在任何安装...
ifconfig iftop ip nc 证书 软件包 媒体 说明:下文中,大写为自定义变量,根据实际情况填写(个别大写的参数除外)。使用[]引起表示内容可选,使用{}引起表示内容为一个整体,|表示使用左侧或右侧内容,...表示重复之前内容。 系统信息 date 查看或设置时间。
/bin/bash # testing multiple commands in the then section # testuser=Christine # if grep $testuser /etc/passwd #使用 grep 命令在/etc/passwd文件中查找某个用户名当前是否在系统上使用。 then echo "This is my first command" echo "This is my second command"...
This variable is equivalent to the ONIE installer command line option --password. CL_INSTALLER_HASHED_PASSWORD Defines the hashed password.This variable is equivalent to the ONIE installer command line option --hashed-password.If you set both the CL_INSTALLER_PASSWORD and CL_INSTALLER_HASHED_...
if[!-s ${REMOTE_FILE}]then SH_error_msg"${REMOTE_FILE} file is empty"return1fi 循环 For for循环的一般格式为: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 for变量in列表docommand1 command2...commandN done 列表 是一组值(数字,字符串等)组成的序列,每个值通过空格分隔。每循环一次,就...
# Set the value of var to var2 if var2 is greater than var. # var: variable to set. # var2>var: Condition to test. # ?var2: If the test succeeds. # :var: If the test fails. ((var=var2>var?var2:var)) TRAPS 陷阱允许脚本在各种信号上执行代码。在pxltrm(用bash编写的像素艺术...