lohaxy.blogg.se - september 2022

As far as I can tell, if every interactive shell sourced "profile" files, nothing terrible would happen, in the default configuration.

That's inefficient and (much more importantly) makes it hard to understand the contents of PATH. If bin exists in your home folder and your username is james, your PATH in the innermost shell is something like: /home/james/bin:/home/james/bin:/home/james/bin:/home/james/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games Suppose you SSH'd in, ran another shell (say, zsh), at some point found you wanted to temporarily go back to bash but keep your environment (so ran bash again while in zsh), and then ran a program like mc that runs a shell as part of its interface.

it would produce an undesired result, to run it more than once per login.Īs an example of the second situation, where an undesirable result would occur, consider these lines, which appear by default in every user's ~/.profile: # set PATH so it includes user's private bin if it exists.

there is no reason to run it more than one time per login, it would be inefficient, or.

You might want to run a command only once because: (This includes graphical logins, as they start with a login shell, too.) If a shell is interactive, the user running it is probably logged on, and so it probably has an ancestor (that started it, or started what started it, or started that, etc.) that was a login shell. "profile" files should contain commands that ought only run once, at the beginning of login. profile and then log in with dash as my shell, it will fail. For example, I can use the [[ evaluation operator in. The benefit of shell-specific profile files is that they can contain commands or syntax that are only valid for that shell. bash_login, when it exists, to be written so as to *explicitly call. bash_login exists, that is run instead of. bash_profile exists, bash runs it instead of. These are ignored by shells other than bash. profile in the user's home directory, run by Bourne-compatible shells when started as a login shell (unless overridden, see below).

For example, on my Ubuntu 12.04 system, /etc/profile includes these lines: if then Rather, commands in /etc/profile calls them. This is for Bourne-style shells, but it's not coded into the shell executable itself. etc/profile, run by all Bourne-compatible shells (including bash and dash) when started as a login shell. The purpose of the "profile" files is to contain commands that ought to be run for login shells only. If you want a command to run for interactive shells that are not login shells, and you're using bash, put it in ~/.bashrc or /etc/bash.bashrc. etc/profile is invoked only for login shells because that is its specific purpose.