sh
or bash
.# shellcheck shell=zsh
export PAGER=less
Any supported shell on the shebang or the -s
option
# shellcheck shell=sh
export PAGER=less
Shellcheck only supports a specific range of shell dialects, there are many more applications providing shell like experiences and some of them look and feel like POSIX shell or bash but does not support the same commands.
One notable unsupported shell type is zsh, see issue #809 about supporting zsh - some efforts have been done in the past.
The supported shell types are listed in the help context, at the moment these are
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.