How can I test if a variable contains a string in a bash script without getting the "command not found" error? [closed]

Question

Closed. This question is not reproducible or was caused by typos. It is not currently accepting answers.

---

This question was caused by a typo or a problem that can no longer be reproduced. While similar questions may be on-topic here, this one was resolved in a way less likely to help future readers.

Closed 9 years ago.

Improve this question

I keep getting a "command not found" error after checking a variable for the substring .txt.

Here's a simple version of my script.

myscript.sh

#!/bin/sh
if [["$1" == *.txt]]
    then
    echo $1
fi

Result:

> ./myscript.sh argument.txt
./myscript.sh: line 2: [[argument.txt: command not found]]

Answer 1

The error is because of a space needed around the brackets [[ and ]]:

#!/bin/sh
if [[ "$1" == *.txt ]]
    then
    echo $1
fi

That is, instead of:

if [["$1" == *.txt]]

use

if [[ "$1" == *.txt ]]