bash - 如何在Bash的'if'语句中比较两个字符串变量？ [重复](How do I compare two string variables in an 'if' statement in Bash? [duplicate])

Question

This question already has an answer here:

(这个问题已经在这里有了答案：)

• How to compare strings in Bash 10 answers

  (如何在Bash中比较字符串 10个答案)

I'm trying to get an if statement to work in Bash (using Ubuntu ):

(我正在尝试让if语句在Bash中工作（使用Ubuntu ）：)

#!/bin/bash

s1="hi"
s2="hi"

if ["$s1" == "$s2"]
then
  echo match
fi

I've tried various forms of the if statement, using [["$s1" == "$s2"]] , with and without quotes, using = , == and -eq , but I still get the following error:

(我已经尝试过各种形式的if语句，使用[["$s1" == "$s2"]] ，使用和不使用引号，使用= ， ==和-eq ，但是仍然出现以下错误：)

[hi: command not found

([hi：找不到命令)

I've looked at various sites and tutorials and copied those, but it doesn't work - what am I doing wrong?

(我查看了各种站点和教程并复制了这些站点和教程，但是它不起作用-我在做什么错？)

Eventually, I want to say if $s1 contains $s2 , so how can I do that?

(最终，我想说一下$s1包含$s2 ，那我该怎么做呢？)

I did just work out the spaces bit.. :/ How do I say contains?

(我只是算出空格位..：/我怎么说包含？)

I tried

(我试过了)

if [[ "$s1" == "*$s2*" ]]

but it didn't work.

(但这没用。)

  ask by Mr Shoubs translate from so

Answer 1

For string comparison, use:

(对于字符串比较，请使用：)

if [ "$s1" == "$s2" ]

For the a contains b , use:

(对于a包含b ，请使用：)

if [[ $s1 == *"$s2"* ]]

(and make sure to add spaces between the symbols):

(（并确保在符号之间添加空格）：)

bad:

(坏：)

if ["$s1" == "$s2"]

good:

(好：)

if [ "$s1" == "$s2" ]