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Anomalous result using bash "set" command

rated 0 times [ 4] [ 0] / answers: 1 / hits: 10195 / 2 Years ago, sun, july 24, 2022, 7:13:49

When one issues the set command without arguments at a bash prompt (which should output a list of shell variables and their values), a script of 8,274 lines scrolls by. Examining this script shows that it is instructions to the shell for executing commands - and it seems that it runs python scripts, making it essentially a kludge of monstrous proportions. I've seen other builtins behave in a few ways

No output:

Me:~$ wait

Me:~$ true

Me:~$ test

An error, with no usage hint:

Me:~$ select

bash: syntax error near unexpected token `newline'

An error, with usage hint:

Me:~$ source

bash: source: filename argument required

source: usage: source filename [arguments]

Me:~$ return

bash: return: can only `return' from a function or sourced script

I'm having trouble understanding why set behaves in this way. It seems undocumented, and I wasn't really expecting it. I'm troubled as to why this happens. Can anyone explain?

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errettas

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4 Years ago

answered 2 Years ago istmasted · Accepted Answer

Those 8k lines are mainly completion functions from the bash-completion package. On my old desktop, bash uses almost a second to read through and define all those functions, most of which I never use, so I disable it.

To disable it, edit your ~/.bashrc, locate these three lines near the end, and prepend a # to each of the lines.

if [ -f /etc/bash_completion ] && ! shopt -oq posix; then

    . /etc/bash_completion

fi

Next time you run an interactive bash session, set will only output about 50-100 lines; mostly environment variables and special shell variables.