Ubuntu – shopt works in command line, not found when run in a script


I'm writing a script to copy some files around, and trying to use shopt -s dotglob to enable cp to copy dotfiles like .jshint and whatnot.

I can run shopt -s dotglob directly at a bash prompt with no error. However, running the script throws the error:

script.sh: 81: script.sh: shopt: not found

I'm running this script in bash shell, with the shebang header #!/usr/bin/env bash. Error line:

shopt -s dotglob
cp -r $TEMP/img/* $TARGET/img/
cp -r $TEMP/js/* $TARGET/js/
cp -r $TEMP/less/* $TARGET/less/

Not finding anything helpful on google, any idea what the problem is here?

Best Answer

To form an answer from the comments:

Many people out of habit run their scripts with sh instead of bash. This is a good practice if portability is a concern, but many people do so because they're copying something they've seen without understanding it.

Unless your script needs to run on a non-desktop Linux system (e.g., running shell scripts on Android devices is quite different), I recommend using the Bash shebang line at the beginning:


This line, when it's the first line in the script, determines which interpreter (shell such as bash or sh, Python, etc.) is called to execute it. If you use the above line, you'll get the same behavior (almost) as you do from the command line, assuming you use the default shell. If for reasons of portability or preference you use a different shebang line, be aware that you'll have to consult the documentation for the shell you've referenced, even if the shell you reference is a symlink to Bash.