source: postlfs/config/profile.xml@ 036393e1

<sect1 id="postlfs-config-profile">
<?dbhtml filename="profile.html" dir="postlfs"?>
<title>The Bash Shell Startup Files</title>

<para>The shell program <filename>/bin/bash</filename> (hereafter
referred to as just "the shell") uses a collection of startup files to
help create an environment to run in.  Each file has a specific use and
may affect login and interactive environments differently.</para>

<para>An interactive login shell is started after a successful login by
<filename>/bin/login</filename> by reading the
<filename>/etc/passwd</filename> file.  An
interactive non-login shell is started at the command line (e.g.
[prompt]$<userinput>/bin/bash</userinput>).  A non-interactive shell is
usually present when a shell script is running.  It is non-interactive
because it is processing a script and not waiting for user input between
commands.</para>

<para>For more information see <filename>info bash</filename> -- Nodes:
Bash Startup Files and Interactive Shells</para>

<para>The following files are needed to make sure that the correct
environment is read for each of the ways the shell can be invoked:
<filename>/etc/profile</filename>, <filename>/etc/bashrc</filename>,
<filename>~/.bash_profile</filename>, and
<filename>~/.bashrc</filename>.  The file
<filename>~/.bash_logout</filename> is not used for an invocation of the
shell.  It is read by the shell when a user logouts of the system.  The
files <filename>/etc/profile</filename> and
<filename>~/.bash_profile</filename> are read when the shell is invoked
as a interactive login shell.  The file <filename>~/.bashrc</filename>
is read when the shell is invoked as an interactive non-login
shell.</para> 

<para>Here is a base <filename>/etc/profile</filename>.  Comments in the
file should explain everything you need.  For more information on the
escape sequences you can use for your prompt (e.g.  the PS1 environment
variable) see <filename>info bash</filename> -- Node: Printing a
Prompt.</para>

<para><screen># Begin /etc/profile
# Written for Beyond Linux From Scratch
# by James Robertson &lt;jameswrobertson@earthlink.net&gt;

# System wide environment variables and startup programs.

# System wide aliases and functions should go in /etc/bashrc.  Personal
# environment variables and startup programs should go into
# ~/.bash_profile.  Personal aliases and functions should go into
# ~/.bashrc.

# Function to help us manage paths
pathman () {
        if ! echo $PATH | /bin/egrep -q "(^|:)$1($|:)" ; then
                if [ "$2" = "last" ] ; then
                        PATH=$PATH:$1
                else
                        PATH=$1:$PATH
                fi
        fi
}

# Add to the standard path.
if [ $(id -u) = 0 ] ; then
        if [ -d "/usr/local/sbin" ] ; then
                pathman /usr/local/sbin last
        fi
fi

if [ $(id -u) != 0 ] ; then
        if [ -d "/usr/local/bin" ] ; then
                pathman /usr/local/bin last
        fi
fi

if [ -d "/usr/X11R6/bin" ] ; then
        pathman /usr/X11R6/bin last
fi

# Setup some environment variables.
HISTSIZE=1000
PS1="[\u@\h \w]\\$ "

# Setup the INPUTRC environment variable.
if [ -z "$INPUTRC" -a ! -f "$HOME/.inputrc" ] ; then
        INPUTRC=/etc/inputrc
fi

# Setup for /bin/ls to support color, the alias is in /etc/bashrc.
if [ -f "/etc/dircolors" ] ; then
        eval $(dircolors -b /etc/dircolors)

        if [ -f "$HOME/.dircolors" ] ; then
                eval $(dircolors -b $HOME/.dircolors)
        fi
fi

export PATH HISTSIZE PS1 LS_COLORS INPUTRC

# End /etc/profile</screen></para>

<para>Here is a base <filename>/etc/bashrc</filename>.  Comments in the
file should explain everything you need.</para>

<para><screen># Begin /etc/bashrc 
# Written for Beyond Linux From Scratch 
# by James Robertson &lt;jameswrobertson@earthlink.net&gt;

# System wide aliases and functions.

# System wide environment variables and startup programs should go into
# /etc/profile.  Personal environment variables and startup programs
# should go into ~/.bash_profile.  Personal aliases and functions should
# go into ~/.bashrc

# By default we want the umask to get set.
# Even for non-interactive and non-login shells.
if [ "$(id -gn)" = "$(id -un)" -a $(id -u) -gt 99 ] ; then
        umask 002
else
        umask 022
fi

# Provides a colored /bin/ls command.  Used in conjunction with code in
# /etc/profile.
alias ls='ls --color=auto'

# End /etc/bashrc</screen></para>

<para>Here is a base <filename>~/.bash_profile</filename>.  Comments in
the file should explain everything you need.</para>

<para><screen># Begin ~/.bash_profile
# Written for Beyond Linux From Scratch
# by James Robertson &lt;jameswrobertson@earthlink.net&gt;

# Personal environment variables and startup programs.

# Personal aliases and functions should go in ~/.bashrc.  System wide
# environment variables and startup programs are in /etc/profile.
# System wide aliases and functions are in /etc/bashrc.

if [ -f "$HOME/.bashrc" ] ; then
        source $HOME/.bashrc
fi

if [ -d "$HOME/bin" ] ; then
        pathman $HOME/bin last
fi

export PATH 

# End ~/.bash_profile</screen></para>

<para>Here is a base <filename>~/.bashrc</filename>.  Comments in the
file should explain everything you need.</para>

<para><screen># Begin ~/.bashrc
# Written for Beyond Linux From Scratch
# by James Robertson &lt;jameswrobertson@earthlink.net&gt;

# Personal aliases and functions.

# Personal environment variables and startup programs should go in
# ~/.bash_profile.  System wide environment variables and startup
# programs are in /etc/profile.  System wide aliases and functions are
# in /etc/bashrc. 

if [ -f "/etc/bashrc" ] ; then
        source /etc/bashrc
fi

# End ~/.bashrc</screen></para>

<para>Here is a base <filename>~/.bash_logout</filename>.  Comments in
the file should explain everything you need.  You will notice that the
base <filename>~/.bash_logout</filename> does not include a
<userinput>clear</userinput> command.  This is because the clear is
handled in the <filename>/etc/issue</filename> file.</para>

<para><screen># Begin ~/.bash_logout
# Written for Beyond Linux From Scratch
# by James Robertson &lt;jameswrobertson@earthlink.net&gt;

# Personal items to perform on logout.

# End ~/.bash_logout</screen></para>

<para>If you want to use the <filename>/etc/dircolors</filename> or
<filename>~/.dircolors</filename> files called from
<filename>/etc/profile</filename>, then run the following: 
<userinput>/bin/dircolors -p > /etc/dircolors</userinput> or 
<userinput>/bin/dircolors -p > ~/.dircolors</userinput> respectively.
The file in the <filename>/etc</filename> directory should be used for
global settings and if one exists in your home directory then it will
overwrite the global settings.  It might be a good idea to create a base
<filename>.dircolors</filename> file and place it in the
<filename>/etc/skel</filename> directory for new users.</para>

<para>Ian Macdonald has written an excellent collection of tips and
tricks to enhance your shell environment.  You can read it online at
<ulink
url="http://www.caliban.org/bash/index.shtml">http://www.caliban.org/bash/index.shtml</ulink></para>

</sect1>