what is the difference between ~/.profile and ~/.bash_profile

Question

I want to know the difference between ~/.profile and ~/.bash_profile.

Answer 1

The .profile was the original profile configuration for the Bourne shell (a.k.a., sh). bash, being a Bourne compatible shell will read and use it. The .bash_profile on the other hand is only read by bash. It is intended for commands that are incompatible with the standard Bourne shell.

Answer 2

A login shell is simply a shell you can login as via it ssh or at the console. A non-login shell is a shell that someone can not login too. A non-login shell is often used by programs/system services.

As for your third point. It is true .bashrc is executed on each instance of the shell. However .bash_profile is only used upon login. Thus the reason for the two separate files.

.profile is for things that are not specifically related to Bash, like environment variables $PATH it should also be available anytime. .bash_profile is specifically for login shells or shells executed at login.

Answer 3

The original sh sourced .profile on startup.

bash will try to source .bash_profile first, but if that doesn't exist, it will source .profile¹.

Note that if bash is started as sh (e.g. /bin/sh is a link to /bin/bash) or is started with the --posix flag, it tries to emulate sh, and only reads .profile.

Footnotes:

1. Actually, the first one of .bash_profile, .bash_login, .profile

See also:

• Bash Reference Manual - Startup Files
• UNIX sh man page - Invocation

Answer 4

You know many shell exist in UNIX world, but most of them are:

Bounre shell == /bin/sh => inventor : Stephon Bourne

BASH (Bourne Again Shell) == /bin/bash => inventor : (Brian Fox , under GNU project) (powerful shell)

C SHELL == /bin/csh ==>   inventor: Bill Joy, Inventor of TCP/IP Stack

Korn Shell == /bin/ksh ==> inventor: David Korn under Bell Labs

Z Shell == /bin/zsh ==> (Powerful sehll)

TENEX C SHELL == /bin/tcsh => derived from c shell

Debian Almquist shell == /bin/dash => derived from  Almquist shell (ash under NetBSD project)  (Dash born from lenny)

But your question about ~/.bash_profile and ~/.profile:

When you you login in UNIX machine redirect to your home directory, According to your shell that administrator chose for you in last field of /etc/passwd such :

mohsen:x:1000:1000:Mohsen Pahlevanzadeh,,,:/home/mohsen:/bin/bash

Your shell will be run and behave for you, By default each has a set file for login and logout when you login in bash shell , ~/.profile is run and when you logout , ~/.bash_logout is run. ~/.bash_history file keeps your input command.

Initialization file in each shell

TENEX C SHELL:

~/.login = > When you login
~/.logout = > When you logout
~/.tcshrc  = > same as ~./bashrc in bash shell
You can set variable $histfile as name of history file and variable $history as number of commands to keeping.

Z SHELL

Indeed it's powerful shell and if i get free time, be sure migrate to it.

Except of other shell, Z shell has many configuration file and initialization files, just i write:

$ZDOTDIR/.zshenv
$ZDOTDIR/.zprofile
$ZDOTDIR/.zshrc
$ZDOTDIR/.zlogin
$ZDOTDIR/.zlogout
/tmp/zsh*
/etc/zshenv
/etc/zprofile
/etc/zshrc
/etc/zlogin

Note: if $ZDOTDIR unset, home set.

C SHELL

Note: TENEX C shell forked from C Shell, C Shell supports by BSD. If you familiar with C language programing,So you believe its syntax such as that.

    ~/.login
    ~/.cshrc
    ~/.logout
Note : if you need to it, use tcsh and csh is old but live.

Korn Shell

~/.profile
rc file == user defined
logout file ==  N/A

Bourne Again SHell (BASH)

It's very very powerful shell and born under GNU project and forked by Bourne Shell.

~/.bash_login
~/.bash_logout
~/.bashrc
~/.bash_profile
~/.bash_history
When you login, bash runs ~/.bash_profile and ~/.bash_profile runs ~/.bashrc, indeed ~/.bashrc isn't bash initialization file.Because bash doesn't run it.

Bourne Shell

It dead, Even when you use man sh, you see manual of dash.

Your Answer:

~/.bash_profile work under bash shell, but ~/.profile work under bourne and korn shell