glfs/introduction/welcome/bash-profile.xml

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   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
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<sect1 id="bash-profile" xreflabel="The Bash Shell Startup Files">
  <?dbhtml filename="bash-profile.html"?>


  <title>The Bash Shell Startup Files</title>

  <para>
    Bash, or the shell, can source a file at startup that applies for all
    users, which can be very helpful for many different purposes. This can
    involve setting many useful variables to adding new functionality to the
    shell, usually for convenience. This section is therefore recommended and
    setting up packages in this book will rely on this section and the created
    files. There is little downside to following this section unless you are
    not able to copy and paste the following commands, in which case there will
    be a lot of typing involved. Doing this in a chroot is recommended before
    booting back into your LFS system.
  </para>

  <note>
    <para>
      Most of the instructions below are used to create files located in the
      <filename class='directory'>/etc</filename> directory structure which
      requires you to execute the commands as the <systemitem
      class='username'>root</systemitem> user. If you elect to create the
      files in user's home directories instead, you should run the commands
      as an unprivileged user.
    </para>
  </note>

  <note>
    <para>
      There are more startup files that can be made. The ones here establish
      a basic setup while offering convenience. For more startup files, see
      <ulink url="&blfs-svn;/postlfs/profile.html">BLFS Bash Startup Files.
      </ulink>
    </para>
  </note>

  <sect2 id="etc-profile-profile">
    <title>/etc/profile</title>

    <indexterm zone="bash-profile etc-profile-profile">
      <primary sortas="e-etc-profile">/etc/profile</primary>
    </indexterm>

    <para>
      Here is a base <filename>/etc/profile</filename>. This file starts by
      setting up some helper functions and some basic parameters. It specifies
      some <command>bash</command> history parameters and, for security
      purposes, disables keeping a permanent history file for the <systemitem
      class="username">root</systemitem> user.  It also sets a default user
      prompt.  It then calls small, single purpose scripts in the <filename
      class='directory'>/etc/profile.d</filename> directory to provide most
      of the initialization.
    </para>

    <para>
      For more information on the escape sequences you can use for your prompt
      (i.e., the <envar>PS1</envar> environment variable) see <command>info
      bash</command> -- <emphasis role="strong">Node: Printing a
      Prompt</emphasis>.
    </para>

<screen role="root"><?dbfo keep-together="auto"?><userinput>cat &gt; /etc/profile &lt;&lt; "EOF"
<literal># Begin /etc/profile
# Written for Beyond Linux From Scratch
# by James Robertson &lt;jameswrobertson@earthlink.net&gt;
# modifications by Dagmar d'Surreal &lt;rivyqntzne@pbzpnfg.arg&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.

# Functions to help us manage paths.  Second argument is the name of the
# path variable to be modified (default: PATH)
pathremove () {
        local IFS=':'
        local NEWPATH
        local DIR
        local PATHVARIABLE=${2:-PATH}
        for DIR in ${!PATHVARIABLE} ; do
                if [ "$DIR" != "$1" ] ; then
                  NEWPATH=${NEWPATH:+$NEWPATH:}$DIR
                fi
        done
        export $PATHVARIABLE="$NEWPATH"
}

pathprepend () {
        pathremove $1 $2
        local PATHVARIABLE=${2:-PATH}
        export $PATHVARIABLE="$1${!PATHVARIABLE:+:${!PATHVARIABLE}}"
}

pathappend () {
        pathremove $1 $2
        local PATHVARIABLE=${2:-PATH}
        export $PATHVARIABLE="${!PATHVARIABLE:+${!PATHVARIABLE}:}$1"
}

export -f pathremove pathprepend pathappend

# Set the initial path
export PATH=/usr/bin

# Attempt to provide backward compatibility with LFS earlier than 11
if [ ! -L /bin ]; then
        pathappend /bin
fi

if [ $EUID -eq 0 ] ; then
        pathappend /usr/sbin
        if [ ! -L /sbin ]; then
                pathappend /sbin
        fi
        unset HISTFILE
fi

# Set up some environment variables.
export HISTSIZE=1000
export HISTIGNORE="&amp;:[bf]g:exit"

# Set some defaults for graphical systems
export XDG_DATA_DIRS=${XDG_DATA_DIRS:-/usr/share}
export XDG_CONFIG_DIRS=${XDG_CONFIG_DIRS:-/etc/xdg}
export XDG_RUNTIME_DIR=${XDG_RUNTIME_DIR:-/tmp/xdg-$USER}

# Set up a red prompt for root and a green one for users.
NORMAL="\[\e[0m\]"
RED="\[\e[1;31m\]"
GREEN="\[\e[1;32m\]"
if [[ $EUID == 0 ]] ; then
  PS1="$RED\u [ $NORMAL\w$RED ]# $NORMAL"
else
  PS1="$GREEN\u [ $NORMAL\w$GREEN ]\$ $NORMAL"
fi

for script in /etc/profile.d/*.sh ; do
        if [ -r $script ] ; then
                . $script
        fi
done

unset script RED GREEN NORMAL

# End /etc/profile</literal>
EOF</userinput></screen>

    <sect3 id="etc-profile.d">
      <title>The /etc/profile.d Directory</title>

      <indexterm zone="bash-profile etc-profile.d">
        <primary sortas="e-etc-profile.d">/etc/profile.d</primary>
      </indexterm>

      <para>
        Now create the <filename class='directory'>/etc/profile.d</filename>
        directory, where the individual initialization scripts are placed:
      </para>

<screen role="root"><userinput>install --directory --mode=0755 --owner=root --group=root /etc/profile.d</userinput></screen>

    </sect3>

    <sect3 id="extrapaths.sh">
      <title>/etc/profile.d/extrapaths.sh</title>

      <indexterm zone="bash-profile extrapaths.sh">
        <primary sortas="e-etc-profile.d-extrapaths.sh">/etc/profile.d/extrapaths.sh</primary>
      </indexterm>

      <para>
        This script adds some useful paths to the <envar>PATH</envar> and
        can be used to customize other PATH related environment variables
        (e.g. LD_LIBRARY_PATH, etc) that may be needed for all users.
      </para>

<screen role="root"><userinput>cat &gt; /etc/profile.d/extrapaths.sh &lt;&lt; "EOF"
<literal>if [ -d /usr/local/lib/pkgconfig ] ; then
        pathappend /usr/local/lib/pkgconfig PKG_CONFIG_PATH
fi
if [ -d /usr/local/bin ]; then
        pathprepend /usr/local/bin
fi
if [ -d /usr/local/sbin -a $EUID -eq 0 ]; then
        pathprepend /usr/local/sbin
fi

if [ -d /usr/local/share ]; then
        pathprepend /usr/local/share XDG_DATA_DIRS
fi

# Set some defaults before other applications add to these paths.
pathappend /usr/share/info INFOPATH</literal>
EOF</userinput></screen>

      <note>
        <para>
          The <command>man</command> program automatically deduce the search
          path for man pages by examining the content of the
          <envar>PATH</envar> variable, see
          <ulink role='man' url='&man;manpath.5'>manpath(5)</ulink> for
          details.  Setting the <envar>MANPATH</envar> variable may override
          the automatic deduction, so the BLFS editors do not recommend to
          set it.  If you must set it for any reason, it's better to start
          its value with a colon (<literal>:</literal>), for example
          <command>MANPATH=:/opt/somepkg/share/man:/opt/otherpkg/share/man</command>
          so the paths listed in the <envar>MANPATH</envar> variable will
          be appended to the automatically deduced value instead of
          overriding it.
        </para>
      </note>

    </sect3>

    <sect3 id="umask.sh">
      <title>/etc/profile.d/umask.sh</title>

      <indexterm zone="bash-profile umask.sh">
        <primary sortas="e-etc-profile.d-umask.sh">/etc/profile.d/umask.sh</primary>
      </indexterm>

      <para>
        Setting the <command>umask</command> value is important for security.
        Here the default group write permissions are turned off for system
        users and when the user name and group name are not the same.
      </para>

<screen role="root"><userinput>cat &gt; /etc/profile.d/umask.sh &lt;&lt; "EOF"
<literal># By default, the umask should be set.
if [ "$(id -gn)" = "$(id -un)" -a $EUID -gt 99 ] ; then
  umask 002
else
  umask 022
fi</literal>
EOF</userinput></screen>

    </sect3>

    <sect3 id="i18n.sh">
    <!-- This is handled system wide on systemd but LANG is not exported to
         the environment, hence it's return...need to add additional text for
         systemd only -->
      <title>/etc/profile.d/i18n.sh</title>

    <indexterm zone="bash-profile i18n.sh">
      <primary sortas="e-etc-profile.d-i18n.sh">/etc/profile.d/i18n.sh</primary>
    </indexterm>

      <para>
        This script sets an environment variable necessary for
        native language support. A full discussion on determining this
        variable can be found on the <ulink
	url="&lfs-website;/~thomas/multilib/chapter09/locale.html">
	Configuring the System Locale</ulink> page.
      </para>

<screen role="root"><userinput>cat &gt; /etc/profile.d/i18n.sh &lt;&lt; "EOF"
<literal># Set up i18n variables
for i in $(locale); do
  unset ${i%=*}
done

if [[ "$TERM" = linux ]]; then
  export LANG=C.UTF-8
else
  export LANG=<replaceable>&lt;ll&gt;</replaceable>_<replaceable>&lt;CC&gt;</replaceable>.<replaceable>&lt;charmap&gt;</replaceable><replaceable>&lt;@modifiers&gt;</replaceable>
fi</literal>
EOF</userinput></screen>

    </sect3>

  </sect2>

</sect1>