在Bash Shell中,可以使用复合条件来在一个if语句中检查多个条件。复合条件主要有两种形式:逻辑与(&&)和逻辑或(||)。 1. 逻辑与(&&): - 概念:逻辑与用于同时检查多个条件...
if stat "/path/to/file" >/dev/null 2>&1; then echo "File exists." else echo "File...
文件&字符串&算术等测试操作,主要方便调试判断的使用。 #文件测试操作-d FILE_NAM # TrueifFILE_NAM is a directory-e FILE_NAM # TrueifFILE_NAM exists-f FILE_NAM # TrueifFILE_NAM existsandis a regular file-r FILE_NAM # TrueifFILE_NAM is readabl...
#ifrunning bashif[ -n"$BASH_VERSION"];then# include .bashrcifit existsif[ -f"$HOME/.bashrc"];then."$HOME/.bashrc"fifi# set PATH so it includes user's private bin directoriesPATH="$HOME/bin:$HOME/.local/bin:$PATH" 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. ~/.profile 这个文件内...
-le 小于等于,如:if [ "a"−le"b" ] < 小于(需要双括号),如:(("a"<"b")) <= 小于等于(需要双括号),如:(("a"<="b")) > 大于(需要双括号),如:(("a">"b")) >= 大于等于(需要双括号),如:(("a">="b")) 字符串比较 : ...
执行命令区域，否则 不进入循环，介绍while 命令 行3，执行命令区域，这些命令中，Bash，Unix shell的...
Checkkeys.sh #!/bin/bash#用case语句和通配符判断用户输入的字符是数字、字母还是其他字符。read-p"请输入一个字符,并按Enter键确认:"KEYcase"$KEY"in[a-z]|[A-Z])#如果输入的字符(只能是1位,aD则会跳到兜底)是大写字母或者小写字母,则输出是字母echo"您输入的是 字母。";; ...
Example 3: File Check #!/bin/bash file_path="/path/to/file.txt" if [ -f "$file_path" ] then echo "File exists." else echo "File does not exist." fi Compound Condition You can combine multiple conditions using logical operators like && (AND) and || (OR). Here’s an example:...
[root@localhost ~]# echo "this is a comment if '#' exists and leads the line."this is a commentif'#'exists and leads the line.[root@localhost ~]# #echo "this is a comment if '#' exists and leads the line."[root@localhost ~]# ...
When bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile, if GNU Bash-4.1 Last change: 2009 December 29 3 User Commands BASH(1) that file exists. After reading that file,...