How do I compare two string variables in an 'if' statement in Bash?
I'm trying to get an if statement to work in Bash (using 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:
[hi: command not found
I've looked at various sites and tutorials and copied those, but it doesn't work - what am I doing wrong?
Eventually, I want to say if $s1 contains $s2 , so how can I do that?
I did just work out the spaces bit.. :/ How do I say contains?
I tried
if [[ "$s1" == "*$s2*" ]]
but it didn't work.
For string comparison, use:
if [ "$s1" == "$s2" ]
For the a contains b , use:
if [[ $s1 == *"$s2"* ]]
(and make sure to add spaces between the symbols):
bad:
if ["$s1" == "$s2"]
good:
if [ "$s1" == "$s2" ]
你需要空间：
if [ "$s1" == "$s2" ]
You should be careful to leave a space between the sign of '[' and double quotes where the variable contains this:
if [ "$s1" == "$s2" ]; then
# ^ ^ ^ ^
echo match
fi
The ^ s show the blank spaces you need to leave.
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