9. Bash if / else / fi statements 9.1. Simple Bash if/else statement Please note the spacing inside the [ and ] brackets! Without the spaces, it won't work! #!/bin/bash directory="./BashScripting" # bash check if directory exists if [ -d $directory ]; then echo "Directory exists...
Run one of the following commands to check if the file exists: Check if the directory still exists The -d operator allows you to test if a file is a directory. For example, to check if the /etc/filetocheck directory exists, you can use: NOTE: You can also use double brackets [[ i...
mkdir:Make Directory(创建目录) touch:touch man:Manual su:Swith user(切换用户) cd:Change directory ls:List files mkfs:Make file system fsck:File system check uname:Unix name lsmod:List modules mv:Move file cp:Copy file ln:Link files fg:Foreground bg:Background chown:Change owner chgrp:Change...
if [ ! -z err−o!−eapk ]; then 会报出-e无法找到的错误; 而if [ ! -z err]||[!−eapk ]; then 没问题; 整数比较 : -eq 等于,如:if [ "a"−eq"b" ] -ne 不等于,如:if [ "a"−ne"b" ] -gt 大于,如:if [ "a"−gt"b" ] -ge 大于等于,如:if [ "a"−ge...
How to check if a variable exists or is “null”? How to check if a file exists? How to check if a directory exists? How to check if a command succeeds or failed? How to do string comparison and check if a string equals to a value? How to check if a string is in an array?
- Test if the specified variable has an empty value: [[ -z $variable ]] - Test if the specified [f]ile exists: [[ -f path/to/file ]] - Test if the specified [d]irectory exists: [[ -d path/to/directory ]] - Test if the specified file or directory [e]xists: ...
$ if [ -x a.out ]; then echo "File is executable"; else echo "File is not executable"; fi File is executable So, thetest‘sxflag proves if the file exists and is executable. 3. Ruling out the Directories Now let’s notice that thetest‘sxcheck alone would suggestthat a folderfoo...
问Bash脚本(#!/bin/bash )权限错误(chown，chmod)EN我希望有人能帮忙。我不是专业人士，也不从事这个...
Write a Bash script that checks if a file named "test.txt" exists in the current directory and prints a message accordingly. Code: #!/bin/bash# Check if "test.txt" exists in the current directoryif[-f"test.txt"];thenecho"File 'test.txt' exists in the current directory."elseecho"Fil...
bash will use whatever regex engine is installed on the user's system. Stick to POSIX regex features if aiming for compatibility.CAVEAT: This example only prints the first matching group. When using multiple capture groups some modification is needed....