Bash Script Linter

'set -e' exits on error, 'set -u' treats unset variables as errors, 'set -o pipefail' makes pipelines fail if any command fails (not just the last). Together they prevent scripts from silently continuing after errors. Without these, a script can appear to succeed while producing incorrect results.

An unquoted variable like $var is subject to word splitting and glob expansion. If the variable contains spaces or special characters, it splits into multiple arguments unexpectedly. Always quote variables: "$var". Use "${var}" inside strings. Exception: inside [[ ]] bash conditionals, quotes are less critical but still a good habit.

Bash-specific features like [[ ]], arrays, and process substitution don't work in /bin/sh on systems where sh is dash or another POSIX shell. If your shebang is #!/bin/sh, avoid bashisms. If you need bash features, use #!/bin/bash explicitly.

Parsing ls output is fragile — filenames can contain spaces, newlines, and other characters that break text parsing. Use glob patterns (for f in *.log) or find with -exec or -print0/xargs -0 instead.

The single bracket [ ] is a POSIX command that requires quoting. The double bracket [[ ]] is a bash keyword with better handling of empty strings and special characters. Use [[ ]] in bash scripts for string comparisons to avoid unexpected behavior with empty variables.