In Debian, shell scripts that have #!/usr/bin/sh as the first line are executed by the 'dash' shell.
If you write such scripts, you might be interested to know that 'dash' currently has a behaviour change in Debian version 12 Bookworm compared to Debian version 11 Bullseye. This is being discussed at https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1028002 Below is a demo of the change which shows an example of possible consequences. In Debian version 11 Bullseye, Bash and 'dash' behave the same: $ cat /etc/debian_version 11.6 $ mkdir eek $ cd eek $ touch aa bb 11 22 $ bash $ echo [!0-9]* aa bb $ echo [^0-9]* aa bb $ sh $ echo [!0-9]* aa bb $ echo [^0-9]* aa bb In Debian version 12 Bookworm, Bash and 'dash' behave differently: $ cat /etc/debian_version 12.0 $ mkdir eek $ cd eek $ touch aa bb 11 22 $ bash $ echo [!0-9]* aa bb $ echo [^0-9]* aa bb $ sh $ echo [!0-9]* aa bb $ echo [^0-9]* 11 22 <------ new behaviour by dash
