【随笔记】简单梳理/etc/profile、/etc/bashrc、/etc/profile.d/、~/.bash_profile、~/.bashrc

结论：

在 /etc/profile 中配置系统变量；

在 ~/.bash_profile 中配置用户变量；

CentOS7系统

1、/etc/profile

[root@centos7 ~]# cat /etc/profile
# /etc/profile

# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.

pathmunge () {
    case ":${PATH}:" in
        *:"$1":*)
            ;;
        *)
            if [ "$2" = "after" ] ; then
                PATH=$PATH:$1
            else
                PATH=$1:$PATH
            fi
    esac
}


if [ -x /usr/bin/id ]; then
    if [ -z "$EUID" ]; then
        # ksh workaround
        EUID=`/usr/bin/id -u`
        UID=`/usr/bin/id -ru`
    fi
    USER="`/usr/bin/id -un`"
    LOGNAME=$USER
    MAIL="/var/spool/mail/$USER"
fi

# Path manipulation
if [ "$EUID" = "0" ]; then
    pathmunge /usr/sbin
    pathmunge /usr/local/sbin
else
    pathmunge /usr/local/sbin after
    pathmunge /usr/sbin after
fi

HOSTNAME=`/usr/bin/hostname 2>/dev/null`
HISTSIZE=1000
if [ "$HISTCONTROL" = "ignorespace" ] ; then
    export HISTCONTROL=ignoreboth
else
    export HISTCONTROL=ignoredups
fi

export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL

# By default, we want umask to get set. This sets it for login shell
# Current threshold for system reserved uid/gids is 200
# You could check uidgid reservation validity in
# /usr/share/doc/setup-*/uidgid file
if [ $UID -gt 199 ] && [ "`/usr/bin/id -gn`" = "`/usr/bin/id -un`" ]; then
    umask 002
else
    umask 022
fi

for i in /etc/profile.d/*.sh /etc/profile.d/sh.local ; do
    if [ -r "$i" ]; then
        if [ "${-#*i}" != "$-" ]; then
            . "$i"
        else
            . "$i" >/dev/null
        fi
    fi
done

unset i
unset -f pathmunge

2、 /etc/bashrc

[root@centos7 ~]# cat /etc/bashrc
# /etc/bashrc

# System wide functions and aliases
# Environment stuff goes in /etc/profile

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.

# are we an interactive shell?
if [ "$PS1" ]; then
  if [ -z "$PROMPT_COMMAND" ]; then
    case $TERM in
    xterm*|vte*)
      if [ -e /etc/sysconfig/bash-prompt-xterm ]; then
          PROMPT_COMMAND=/etc/sysconfig/bash-prompt-xterm
      elif [ "${VTE_VERSION:-0}" -ge 3405 ]; then
          PROMPT_COMMAND="__vte_prompt_command"
      else
          PROMPT_COMMAND='printf "\033]0;%s@%s:%s\007" "${USER}" "${HOSTNAME%%.*}" "${PWD/#$HOME/~}"'
      fi
      ;;
    screen*)
      if [ -e /etc/sysconfig/bash-prompt-screen ]; then
          PROMPT_COMMAND=/etc/sysconfig/bash-prompt-screen
      else
          PROMPT_COMMAND='printf "\033k%s@%s:%s\033\\" "${USER}" "${HOSTNAME%%.*}" "${PWD/#$HOME/~}"'
      fi
      ;;
    *)
      [ -e /etc/sysconfig/bash-prompt-default ] && PROMPT_COMMAND=/etc/sysconfig/bash-prompt-default
      ;;
    esac
  fi
  # Turn on parallel history
  shopt -s histappend
  history -a
  # Turn on checkwinsize
  shopt -s checkwinsize
  [ "$PS1" = "\\s-\\v\\\$ " ] && PS1="[\u@\h \W]\\$ "
  # You might want to have e.g. tty in prompt (e.g. more virtual machines)
  # and console windows
  # If you want to do so, just add e.g.
  # if [ "$PS1" ]; then
  #   PS1="[\u@\h:\l \W]\\$ "
  # fi
  # to your custom modification shell script in /etc/profile.d/ directory
fi

if ! shopt -q login_shell ; then # We're not a login shell
    # Need to redefine pathmunge, it get's undefined at the end of /etc/profile
    pathmunge () {
        case ":${PATH}:" in
            *:"$1":*)
                ;;
            *)
                if [ "$2" = "after" ] ; then
                    PATH=$PATH:$1
                else
                    PATH=$1:$PATH
                fi
        esac
    }

    # By default, we want umask to get set. This sets it for non-login shell.
    # Current threshold for system reserved uid/gids is 200
    # You could check uidgid reservation validity in
    # /usr/share/doc/setup-*/uidgid file
    if [ $UID -gt 199 ] && [ "`/usr/bin/id -gn`" = "`/usr/bin/id -un`" ]; then
       umask 002
    else
       umask 022
    fi

    SHELL=/bin/bash
    # Only display echos from profile.d scripts if we are no login shell
    # and interactive - otherwise just process them to set envvars
    for i in /etc/profile.d/*.sh; do
        if [ -r "$i" ]; then
            if [ "$PS1" ]; then
                . "$i"
            else
                . "$i" >/dev/null
            fi
        fi
    done

    unset i
    unset -f pathmunge
fi
# vim:ts=4:sw=4

3、~/.bash_profile

# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin

export PATH

4、~/.bashrc

# .bashrc

# User specific aliases and functions

alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'

# Source global definitions
if [ -f /etc/bashrc ]; then
        . /etc/bashrc
fi

5、/etc/profile.d/

[root@centos7 ~]# ls -al /etc/profile.d/
total 84
drwxr-xr-x.  2 root root 4096 May 22 09:47 .
drwxr-xr-x. 75 root root 8192 May 22 10:22 ..
-rw-r--r--.  1 root root  771 Apr 11 13:09 256term.csh
-rw-r--r--.  1 root root  841 Apr 11 13:09 256term.sh
-rw-r--r--.  1 root root  196 Mar 25  2017 colorgrep.csh
-rw-r--r--.  1 root root  201 Mar 25  2017 colorgrep.sh
-rw-r--r--.  1 root root 1741 Apr 11 04:20 colorls.csh
-rw-r--r--.  1 root root 1606 Apr 11 04:20 colorls.sh
-rw-r--r--.  1 root root   80 Apr 11 12:18 csh.local
-rw-r--r--.  1 root root 1706 Apr 11 13:09 lang.csh
-rw-r--r--.  1 root root 2703 Apr 11 13:09 lang.sh
-rw-r--r--.  1 root root  123 Jul 31  2015 less.csh
-rw-r--r--.  1 root root  121 Jul 31  2015 less.sh
-rw-r--r--   1 root root  148 May 22 09:47 path.sh
-rw-r--r--.  1 root root   81 Apr 11 12:18 sh.local
-rw-r--r--.  1 root root  105 Apr 11 07:54 vim.csh
-rw-r--r--   1 root root  269 May 22 09:42 vim.sh
-rw-r--r--.  1 root root  164 Jan 28  2014 which2.csh
-rw-r--r--.  1 root root  169 Jan 28  2014 which2.sh

/etc/profile

 

    |- System wide environment and startup programs, for login setup

    |- 用于登录设置的全系统环境和启动程序

/etc/bashrc

    |- System wide functions and aliases

    |- 系统范围的函数和别名

/etc/profile.d/

    |- It's much better to create a custom.sh shell script in /etc/profile.d/ to make custom changes to your environment, as this will prevent the need for merging in future updates.

    |- 最好在/etc/profile.d/中创建一个custom.Shell脚本，以便对环境进行自定义更改，因为这将避免在将来的更新中合并。

~/.bash_profile

    |- User specific environment and startup programs

    |- 用户特定环境和启动程序

~/.bashrc

    |- User specific aliases and functions

    |- 用户特定别名和函数

系统启动时加载 /etc/profile -> 内部加载 /etc/profile.d/ 路径下的*.sh脚本；

用户登录时加载 ~/.bash_profile -> 内部加载 ~/.bashrc -> 内部加载 /etc/bashrc -> 内部加载 /etc/profile.d/ 路径下的*.sh脚本；

用户退出时加载 ~/.bash_logout ；

结论：

在 /etc/profile 中配置系统变量；

在 ~/.bash_profile 中配置用户变量；