bash, dash and string comparison

bash, dash-shell, string-comparison

Solution

`dash` is a very strict POSIX shell, if it work in `dash` it is almost certain it would work in other POSIX shell.

Try:

if [ "$var" = "string" ]
then
    some_command
fi

Problem

I am trying to compare two strings in a simple shell script. I was using `/bin/sh` instead of `/bin/bash`, and after countless hours of debugging, it turns out sh (which is actually dash) can't handle this block of code: ``` if [ "$var" == "string" ] then do something fi ``` What is a portable way to compare strings using `/bin/sh`? I know I can always do the opposite by using !=, but I am wondering about a cleaner, portable way.

Original source