shellcheck gave me no error

[YvesZHI]

I'm working on Ubuntu 16.04.3 and I've installed the shellcheck with the command apt install shellcheck.

Now I have such a bash script named test.sh:

#!/bin/bash

ssssss
aaaaaa

Obviously there are two errors as ssssss and aaaaaaa are illegal commands. However, when I execute shellcheck test.sh, I get nothing as output. It doesn't seem that the command shellcheck work as expected on my system.

[orbea]

They may not be illegal commands, the user could have a ssssss and / or aaaaaa executable on their system. Shellcheck should not assume what users do or do not call their commands and I do not think this is a bug.

[koalaman]

I would love if ShellCheck was able to correctly determine which commands will not be found when the script runs, but unfortunately this can't be done. It's equivalent to trying to predict which filenames will or won't exist on the system at the time when you run the script. Whitelisting and searching PATH would be possible options, but they're fragile and problematic in their own ways.

If you just want to test your script on something that will produce useful warnings to try it out, you can e.g. use shellcheck.net's example:

#!/bin/sh
## Example of a broken script.
for f in $(ls *.m3u)
do
  grep -qi hq.*mp3 $f \
    && echo -e 'Playlist $f contains a HQ file in mp3 format' 
done