case语句,case可以实现和if一样的功能,但是当条件判断很多的时候,使用if不太方便,比如使用if进行值的比较。 #!/bin/bashread -p"Enter the answer in Y/N: "ANSWERcase"$ANSWER"in[yY] | [yY][eE][sS])#大小写echo"The Answer is Yes :)";;[nN] | ...
1.What is Shell Scripts 2.script的执行差异 3.利用test指令的测试功能 1.数值检测 2.比较文本 3.比较文件 4.多个条件判断 5.利用判断符号[] 4.Shell Scripts的默认变量 (0,0,1...) 5.条件判断式 5.1.利用if ...then 5.2.利用case...in...esac判断 5.3.利用function功能 6.循环loop 6.1 while do...
On major systems, “[“ is offered as an executable, and to check if your system has any such executable, run:which [/usr/bin/[If a path is printed on the terminal, we can also run the following, which prints the help section of the man page to the terminal....
$ type -a echoecho is shell builtinecho is /usr/bin/echoecho is /bin/echo 上面代码表示,echo命令即是内置命令,也有对应的外部程序。 type命令的-t参数,可以返回一个命令的类型:别名(alias),关键词(keyword),函数(function),内置命令(builtin)和文件(file)。 $ type -t bash file $ type -t if k...
Check if a Directory Exists in Bash To check if adirectoryexists, switch the-foption on thetestcommand with-d(for directory). For example: test -d /tmp/testCopy echo $?Copy The output is1, which means that the directory doesn't exist. Create the directory using themkdir commandand reru...
executable("sh") commandLine("./my-script.sh", ".") standardOutput = stdout } } } } 然而,这不起作用,Android Studio给出了这个错误:Cannot access class 'java.io.OutputStream'. Check your module classpath for missing or conflicting dependencies ...
It is a good starting point if you are a beginner. Syntax Explanation #!/bin/bash Used to tell the operating system the path it should use to interpret the file. bash file.sh Used to execute the script in the terminal. ./file.sh Used to execute the script if it is executable. # ...
for i in "$@"; do [[ $i ]] && IFS=" " tmp_array["${i:- }"]=1 done printf '%s\n' "${!tmp_array[@]}" } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 用法示例: $ remove_array_dups 1 1 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 5 ...
if语句 if语句用来检验一个条件, 如果 条件为真,我们运行一块语句(称为 if-块 ), 否则 我们处理另外一块语句(称为 else-块 )。 else while语句 只要在一个条件为真的情况下,while语句允许你重复执行一块语句。while语句是所谓 循环 语句的一个例子。while语句有一个可选的else从句。
-rIt is used to check if the file exists as a readable file. -wIt is used to check if the file exists as a writable file. -xIt is used to check if the file exists as an executable file. -sIt is used to check if the file exists and if the file is nonzero. ...