str1="Hello" str2="World" if [ "$str1" == "$str2" ]; then echo "Strings are equal" else echo "Strings are not equal" fi 字符串不相等比较:使用叹号加双等号(!=)来比较两个字符串是否不相等。例如: 代码语言:txt 复制 str1="Hello" str2="World"
[ ARG1 OP ARG2 ] “OP” is one of -eq, -ne, -lt, -le, -gt or -ge. These arithmetic binary operators return true if “ARG1” is equal to, not equal to, less than, less than or equal to, greater than, or greater than or equal to “ARG2”, respectively. “ARG1” and “AR...
bash中的条件语句,基础就是Test。 if 先来个实例: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 x=5;if[$x=5];then echo'x equals 5.';elseecho'x does not equal 5';fi # 输出: x equals5. 和我们熟悉的语言非常相似,不妨抽象一下: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 i...
[student@studentvm1 testdir]$ X=1 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi X equals 1 [student@studentvm1 testdir]$ X=0 ; if [ $X -eq 1 ] ; then echo "X equals 1" ; else echo "X does not equal 1" ; fi X does n...
echo"Now in $dir"elseecho"Can't change to $dir"fi9.test或[]的使用,也不一定要有if 例如 #!/bin/bash var1=20var2=22["$var1"-ne"$var2"] && echo"$var1 is not equal to $var2"home=/home [-d $home ] || echo"$home directory does not exist"注意:&&:前一个操作失败,后一个...
/bin/bashfile="example.txt"if[ -e$file];thenecho"File exists."elseecho"File does not exist."fi 在这个示例中,脚本检查example.txt文件是否存在。 6. 组合条件 在Bash 中,可以使用逻辑运算符组合多个条件: 逻辑与:-a或&& 逻辑或:-o或||
#!/bin/bash if [ $# -lt 1 ];then echo "At least one argument" exit 1 fi if ! id $1 &>/dev/null;then echo "the user does not exist" exit 2 fi if id $1 &>/dev/null;then if [[ `id -u $1` -ge 500 ]] && [[ `grep 'bash$' /etc/passwd | cut -d: -f7` ]]...
[ ARG1 OP ARG2 ] “OP” is one of -eq, -ne, -lt, -le, -gt or -ge. These arithmetic binary operators return true if “ARG1” is equal to, not equal to, less than, less than or equal to, greater than, or greater than or equal to “ARG2”, respectively. “ARG1” and “AR...
[ ARG1 OP ARG2 ] “OP” is one of -eq, -ne, -lt, -le, -gt or -ge. These arithmetic binary operators return true if “ARG1” is equal to, not equal to, less than, less than or equal to, greater than, or greater than or equal to “ARG2”, respectively. “ARG1” and “AR...
#!/bin/bash file="/path/to/your/file.txt" if [ -e "$file" ]; then echo "File exists" else echo "File does not exist" fi 提示与注意事项 使用双引号将变量括起来是一个好习惯,可以防止由于变量为空或包含空格而导致的错误。 在复杂的条件判断中,可以使用逻辑运算符 &&(与)和 ||(或),以...