$ what if type find what
if
    keyword
type
    builtin
find
    file
        path: /usr/bin/find
        file type: ELF 64-bit LSB shared object
what
    function
        source: /home/wja/.local/lib/bash/what.sh:348
        export: no

$ what awk sh ls
awk
    file
        path: /usr/bin/awk
            symlink: /etc/alternatives/awk
            symlink: /usr/bin/mawk
        file type: ELF 64-bit LSB shared object
sh
    file
        path: /bin/sh
            symlink: dash
            canonical path: /bin/dash
        file type: ELF 64-bit LSB shared object
ls
    alias
        possible source: /home/wja/.bash_aliases
    file
        path: /bin/ls
        file type: ELF 64-bit LSB shared object

$ function foo { bar; }
$ what -d foo ll
foo
    function
        source: main:2
        export: no
        definition:
            foo ()
            {
                bar
            }
ll
    alias
        possible source: /home/wja/.bash_aliases:25
            definition: alias ll='ls -alF'  # all, long, classified
        definition: alias ll='ls -alF'

$ alias ll='do_something_else'
$ what -d ll
ll
    alias
        possible source: /home/wja/.bash_aliases:25
            definition: alias ll='ls -alF'  # all, long, classified
        definition: alias ll='do_something_else'

$ hash -p /nonexistent FAKE_COMMAND
$ what FAKE_COMMAND
bash: what: FAKE_COMMAND: File does not exist: /nonexistent

$ what -h
Usage: what [-hiv] [-dnt] [name ...]

Give information about Bash command names, like a more thorough "type".

Arguments:
    NAME    Command name to give information about.
            If none are given, input is taken from stdin.

Options:
    -d      Print definitions for aliases and functions.
    -h      Print this help message and exit.
    -i      Print the info message and exit.
    -n      Provide more info if a command is not found.
            Uses "/usr/lib/command-not-found" (available on Debian/Ubuntu)
    -t      Print only types, similar to "type -at".
    -v      Print the version and exit.

Exit Status:
    4 - Missing dependency ("symlink-info" or optionally the "-n" handler)
    3 - Invalid options
    1 - At least one NAME is not found, or any other error
    0 - otherwise

$ what -i
Info provided per type (types ordered by precedence):
    alias
        - possible source file(s) and line number(s)
            - (with option "-d": definition in file)
        - (with option "-d": current definition)
    keyword
    function
        - source file and line number
        - marked for export (yes/no)
        - (with option "-d": definition)
    builtin
    hashed file (though not a type per se)
        - (if hashed file does not exist: warning)
        - path
    file(s)
        - path
            - (if symlink: details from "symlink-info")
        - file type

Always iterates over multiple types/instances, e.g:
    - echo: builtin and file
    - zsh: two files on Debian

For example:
    "what if type ls what zsh sh /"
    - Covers keyword, builtin, alias/file, function, multiple
      files/absolute symlinks, relative symlink (on Debian/Ubuntu),
      and non-command.

Known issues:
    - Bash may have different output between "type COMMAND" and
      "type -a COMMAND" if COMMAND is a file but is not executable.
      That includes:
        - If the user doesn't have execute permissions to the file
        - If the file is a directory
        - If the file does not exist, as a hashed path
      Some of this behaviour depends on the version of Bash.

      Since "what" relies on the output of "type" to make sense of the
      environment, it will print an error or warning if affected.

$ symlink-info /usr/bin/awk /bin/sh
/usr/bin/awk
    symlink: /etc/alternatives/awk
    symlink: /usr/bin/mawk
/bin/sh
    symlink: dash
    canonical path: /bin/dash

$ symlink-info -h
Usage: symlink-info [-hv] [file ...]

Resolve a symlink, recursively and canonically.

Arguments:
    FILE    Filename of symlink to resolve.

Options:
    -h      Print this help message and exit.
    -v      Print the version and exit.

Info provided per symlink:
    - target, recursively
    - (if relative: canonical path)
    - (if broken: warning)

Exit Status:
    3 - Invalid options
    1 - At least one FILE is not found, or any other error
    0 - otherwise