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Is there a Linux command that will list all available commands and aliases for this terminal session?

As if you typed 'a' and pressed tab, but for every letter of the alphabet. Or running 'alias' but also returning commands.

Why? I'd like to run the following and see if a command is available:

ListAllCommands | grep searchstr

Answers

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.