SC2103.md

Pattern: Missing exit status check or subshell for cd

Issue: -

Description

When doing cd dir; somestuff; cd .., cd dir can fail when permissions are lacking, if the dir was deleted, or if dir is actually a file.

In this case, somestuff will run in the wrong directory and cd .. will take you to an even more wrong directory. In a loop, this will likely cause the next cd to fail as well, propagating this error and running these commands far away from the intended directories.

Check cds exit status and/or use subshells to limit the effects of cd.

Example of incorrect code:

for dir in */
do
  cd "$dir"
  convert index.png index.jpg
  cd ..
done

Example of correct code:

for dir in */
do
  (
  cd "$dir" || exit
  convert index.png index.jpg
  )
done

or

for dir in */
do
  cd "$dir" || exit
  convert index.png index.jpg
  cd ..
done

Exceptions

If you set variables you can't use a subshell. In that case, you should definitely check the exit status of cd, which will also silence this suggestion.

Further Reading

• ShellCheck - SC2103