Linux command to list all available commands and aliases

You can use the bash(1) built-in compgen

• compgen -c will list all the commands you could run.
• compgen -a will list all the aliases you could run.
• compgen -b will list all the built-ins you could run.
• compgen -k will list all the keywords you could run.
• compgen -A function will list all the functions you could run.
• compgen -A function -abck will list all the above in one go.

Check the man page for other completions you can generate.

To directly answer your question:

compgen -ac | grep searchstr

should do what you want.

Add to .bashrc

function ListAllCommands{    echo -n $PATH | xargs -d : -I {} find {} -maxdepth 1 \        -executable -type f -printf '%P\n' | sort -u}

If you also want aliases, then:

function ListAllCommands{    COMMANDS=`echo -n $PATH | xargs -d : -I {} find {} -maxdepth 1 \        -executable -type f -printf '%P\n'`    ALIASES=`alias | cut -d '=' -f 1`    echo "$COMMANDS"$'\n'"$ALIASES" | sort -u}

There is the

type -a mycommand

command which lists all aliases and commands in $PATH where mycommand is used. Can be used to check if the command exists in several variants. Other than that... There's probably some script around that parses $PATH and all aliases, but don't know about any such script.