if-statement-bash-scripting-example Nested if Statement If 语句和 else 语句可以嵌套在 bash 脚本中。关键字 fi 显示了内部 if 语句的结束,所有 if 语句都应该以关键字 fi 结束。 Syntax : if [ condition_command ] then command1 command2 …….. last_command else if [ condition_command2 ] then c...
Bash, short for "Bourne Again SHell," is a powerful scripting language used in Unix-based operating systems. One of the fundamental constructs in Bash programming is the if statement. The if statement allows you to control the flow of your script based on specific conditions. In this article,...
'Else if'in bash scripting, often written as'elif', is used to check multiple conditions in your code. It is used with the syntax,if [firstStatement]; then... elif [secondCondition]; then... else. It’s a powerful tool that allows your scripts to make decisions based on various scen...
注意，test是一个外部程序，需要衍生出对应的进程，而[是Bash的一个内部函数，因此后者的执行效率更高。
问在bash中使用内联if-statement添加命令参数ENexport export命令将会使得被 export 的变量在运行的...
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Bash if...else Statement Bash Scripting Tutorial - If Statements 通过以上信息,你应该能够理解Linux中if语句的基础概念、优势、类型、应用场景以及常见问题的解决方法。 相关搜索: 语句未结束 asp 语句未结束 asp结束语句 asp 结束语句 python结束语句
最后是靠Advanced Bash-Scripting Guide这本书搞清楚的。 条件部分的意义 很多教程都这么说:condition的代码执行后,如果结果为 true,就继续执行then部分,否则继续执行else部分。跟其它语言的一样的,没区别,例如[ -f file ]判断文件是否存在,文件存在就是 true 了,不存在就是 false 了。
来源:https://www.unix.com/shell-programming-and-scripting/30996-using-grep-if-statement.html 虽然上面是针对是ksh,但是bash同样适合: foritemin*.json;do#grep"perl""$item"> /dev/null#为了不在屏幕上显示grep结果 # 或者:grep-q"perl""$item"if[ $? -eq0];then#如果搜索到perl,则$?会是0,否...
/bin/bash NAME = TEST if id $NAME &> /dev/null ; then echo "user exists" fi 双分支的if语句: if 判断条件; then statement1 statement2 ... else statement4 statement5 ... fi 多分支的if语句: if 判断条件1; then statement1 ......