Suggest recommending editing of .profile, not .bashrc

[rbtcollins]

~/.bashrc is invoked on every new shell, so the path changes are additive, whereas ~/.profile's contents only run once per session, which is why most PATH changes are done to ~/.profile.

When pyenv is added to the path in ~/.bashrc, running 4 or five nested bash shells will result in a path like this:

/home/robertc/.pyenv/plugins/pyenv-virtualenv/shims:/home/robertc/.pyenv/shims:/home/robertc/.pyenv/bin:/home/robertc/.pyenv/plugins/pyenv-virtualenv/shims:/home/robertc/.pyenv/shims:/home/robertc/.pyenv/bin:/home/robertc/.pyenv/plugins/pyenv-virtualenv/shims:/home/robertc/.pyenv/shims:/home/robertc/.pyenv/bin:/home/robertc/.pyenv/plugins/pyenv-virtualenv/shims:/home/robertc/.pyenv/shims:/home/robertc/.pyenv/bin:/home/robertc/.cargo/bin:/home/robertc/bin:/home/robertc/.pyenv/plugins/pyenv-virtualenv/shims:/home/robertc/.pyenv/shims:/home/robertc/.pyenv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin

Which is clearly undesirable - in extreme cases this will cause errors when the environment block becomes exhausted, and even before then will cause performance issues as the same dir is searched again and again for commands.

[joshfriend]

thanks for the suggestion, that sounds good to me.

wouldn't you also want things loaded for login shells, in which case .bash_profile would need to be udpated instead of .profile?

[rbtcollins]

I suspect there is some per-distribution variation here, but at least for Debian and Ubuntu, the default is ~/.profile for login shells, whereas ~/.bash_profile is for bash-specificisms for login shells and typically not used at all.

e.g. from the bash man page:

              Do not read either the system-wide startup file /etc/profile or any of the personal initialization files ~/.bash_profile, ~/.bash_login, or ~/.profile.  By default, bash reads these files when it is invoked as a login shell (see INVOCATION below).

In rustup we only edit ~/.profile and the issues we run into are a) folk not understanding that they need to set the PATH directly for their current session and b) zsh and other off the beaten path shells.

[faraz5040]

Woudn't it be better to check if it's already in PATH? Like this:

PYENV_PATH="$HOME/.pyenv/bin"
grep -E -q "(^|:)$PYENV_PATH($|:)" && PATH="$PATH:$PYENV_PATH"

[rbtcollins]

@alireza4050 doing it without invoking a subprocess would be ok I guess. I think the Google SDK has some array glue that does that in a nifty fashion.

[workingjubilee]

The following trick works to "grep" PATH without a subshell (afaik?) and is part of rust-lang/rustup#2387

#!/bin/sh
# rustup shell setup
# affix colons on either side of $PATH to simplify matching
case ":${PATH}:" in
    *:"${cargo_bin}":*)
        ;;
    *)
        # Prepending path in case a system-installed rustc must be overwritten
        export PATH="${cargo_bin}:${PATH}"
        ;;
esac

[native-api]

The instructions have been moved into Pyenv's codebase and fixed in pyenv/pyenv#1920