If-statement-Bash-Script-Example if-else Statement 除了普通的 if 语句之外,我们还可以用 else 块扩展 if 语句。基本思想是,如果语句为真,则执行 if 块。如果语句为假,则执行 else 块。 Syntax : if [ condition_command ] then command1 command2 …….. last_command else command1 command2 …….. ...
To understand if-else in shell scripts, we need to break down the working of the conditional function. Let us have a look at the syntax of the if-else condition block. if [condition] then statement1 else statement2 fi Copy Here we have four keywords, namely if, then, else and fi....
1.1 if格式 if condition; then commands; fi 1.2 else if 和 else if condition; then...
for file in $a;do echo $file done 24. shell 判断为空 1. 变量通过 " " 引号引起来 如下所示 : ,可以得到结果为 IS NULL. #!/bin/sh para1= if [ ! -n "$ echo "IS NULL" else echo "NOT NULL" fi if [ -z $para1 ];then echo “is null” fi 2. 直接通过变量判断 如下所示 :...
else Command fi 别忘了这个结尾 if语句忘了结尾fi test.sh:line 14: syntax error: unexpected end of fi if的三种条件表达式 if command then if 函数 then 命令执行成功,等于返回0(比如grep ,找到匹配) 执行失败,返回非0(grep,没找到匹配) if[ expression_r_r_r ] ...
if[$grep_rc-eq 0 ];thenecho"$1用户存在系统中..."elif[$cat_rc-eq 0 ];thenecho"$1用户不存在系统中,但拥有家目录"elseecho"$1用户不存在系统,也没有家目录"fi需求2:通过脚本传入两个参数,进行整数关系比较。比如: if.sh [ 1 2 | 2 2 | 2 3 ],请使用双分支和多分支两种方式实现。if[$1...
Naturally, this is not optimal. On top of this, involving more advanced shell features such as loops and conditions, we might end up with some complex syntax. 3. Conditional Statements As we’ve already seen, basicif–elsestatements conform to thePOSIXstandard: ...
shell if else 用法 syntax error near unexpected token `then',1. 错误 #!/bin/bashplatform=$1if[ "$platform"="ibmaix64"]then echo"$platform"else echo"helloooo"fi Error: syntaxerrornearunexpectedtoken`then'原因: 条件语句[符...
'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...
/tmp/e.sh:line7: syntax error: unexpected end offileSytax wrong in/tmp/e.sh. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. [root@localhost ~]# ./mkscript -D "Syntax right"/tmp/f.sh #!/bin/bash# Description:Syntax rightif[$1-eq0];thenechohelloelseechoworldfi# 这次创建一个...