SC2043.md

Pattern: Looping over single, constant value

Issue: -

Description

This rule checks for loops that iterate over a single, constant value. This is most likely a bug in your code, caused not expanding the value in the way you want.

You should make sure that whatever you loop over will expand into multiple words.

Example of incorrect code:

for var in value
do
  echo "$var"
done

Example of correct code:

Correct code depends on what you want to do.

To iterate over files in a directory, instead of for var in /some/dir use:

for var in /some/dir/* ; do echo "$var"; done

To iterate over lines in a file or command output, use a while read loop instead:

somecommand | while IFS= read -r line; do echo "$line"; done

To iterate over words written to a command or function's stdout, instead of for var in somefunction, use

for var in $(somefunction); do echo "$var"; done

To iterate over words in a variable, instead of for var in somevariable, use

for var in $somevariable; do echo "$var"; done

Further Reading

• ShellCheck - SC2043