- Testifa given variable is [eq]ual/[n]ot [e]qual/[g]reater [t]han/[l]ess [t]han/[g]reater than or [e]qual/[l]ess than or [e]qual to the specified number: [[$variable-eq|ne|gt|lt|ge|leinteger]] - Testifthe specified variable has a [n]on-empty value: [[ -n$vari...
my_variable="Hello, World!" echo $my_variable 字符串:可以使用单引号 ' 或双引号 " 来定义字符串。双引号内的变量会被解析,而单引号内的内容则被视为字面量。 str1='Hello' str2="World" combined="$str1, $str2!" echo $combined 数组:Bash 支持一维数组,可以通过索引来访问元素。 my_array=...
/bin/bashecho${var:-"Variable is not set"} ---> Variable is not setecho"1 - Value of var is ${var}" ---> 1- Value of var isecho${var:="Variable is not set"} --->Variable is not set 同时var已经被赋值为Variable is not setecho"2 - Value of var is ${var}" --->2 -...
numberTwelve variable is equal to 12 你所看到的是if语句的第一行,它在检查变量的值是否真的等于12。如果是的话,语句就会停止,并发出numberTwelve is equal to 12的回显,然后在fi之后继续执行你的脚本。如果变量大于12的话,就会执行elif语句,并在fi之后继续执行。当你使用if或if/elif语句时,它是自上而下工作...
- Test if a given variable is equal/not equal to the specified string: [[ $variable ==|!= "string" ]] - Test if a given string conforms the specified glob/regex: [[ $variable ==|=~ pattern ]] - Test if a given variable is [eq]ual/[n]ot [e]qual/[g]reater [t]han/[l]...
else echo "Strings are not equal." fi 2. 使用 tr 命令去除所有空白字符 代码语言:txt 复制 string1=$(echo "your_string" | tr -d '[:space:]') string2=$(echo "your_string" | tr -d '[:space:]') if [ "$string1" == "$string2" ]; then echo "Strings are equal." else echo...
case$variableinpattern1)# commands to be executed if $variable matches pattern1;;pattern2)# commands to be executed if $variable matches pattern2;;*)# commands to be executed if $variable doesn't match any pattern;;esac 示例: #!/bin/bashday="Monday"case$dayinMonday)echo"Today is Monday...
#!/bin/bash echo -n "Enter a number: " read VAR if [[ $VAR -gt 10 ]] then echo "The variable is greater than 10." else echo "The variable is equal or less than 10." fi 코드를 실행하고 숫자를 입력하면 스크립트에서는 숫자가 10보...
*)# commands to be executed if $variable doesn't match any pattern;;esac 示例: #!/bin/bashday="Monday"case$dayinMonday)echo"Today is Monday.";; Tuesday)echo"Today is Tuesday.";; *)echo"It's some other day.";;esac 在这个示例中,case语句根据变量day的值来决定执行哪个代码块。
a is : $a a is : hello 只读变量 使用readonly 命令可以将变量限定为只读变量,这与 C 语言中的 const 常量类型的情况相同. a_var="hello" readonly a_var a_var="world" # Output: bash: read-only variable: a_var 删除变量 使用unset 命令可以删除变量,但是不能删除只读变量。 变量被删除后不...