Basic ~/.bashrc ~/.bash_profile tips thread

Question

A lot of this is borrowed from other sites, including the wiki
This by no means all-inclusive, please add on anything interesting along this topic
About ~/.bash_profile and ~/.bashrc
disclaimer:  I don't use ~/.bash_profile or ~/.profile
there is plenty of documentation on the web on how to use these properly if you're interested
in fact, my ~/.bash_profile looks like this:
#!/bin/sh
### THIS IS A DUMMY FILE
### DON'T NEED TWO FILES TO DO ONE JOB
### LET'S CALL ~/.bashrc INSTEAD
source ~/.bashrc
Now, if you choose to go this method, there's a little trick you can do to eliminate ~/.bash_profile altogether  :twisted:
as root create file /etc/profile.d/bashrc.sh with contents:
#!/bin/sh
source ~/.bashrc
AND
chmod +x /etc/profile.d/bashrc.sh
Since /etc/profile executes everything in /etc/profile.d/ that is chmod executable, the little script we just created will cause ~/.bashrc to be read on every login... I personally prefer this method to the dummy ~/.bash_profile, but I keep both since I share my /home directory across distributions and not all distros are the same.
Now, on to the actual ~/.bashrc:
#!/bin/sh
### ALIASES
alias ls="ls --color"
alias ll="ls --color -lh"
alias la="ls --color -a"
alias pacs="pacsearch"
alias vim="vim -y"
alias nano="nano -w"
### NICE COLOR BASH PROMPT
function bash_prompt
local WHITE="[33[1;37m]"
local default="[33[0;39m]"
local BRIGHTGREEN="[33[1;32m]"
local GREEN="[33[0;32m]"
local CYAN="[33[0;36m]"
local GRAY="[33[0;37m]"
local RED="[33[0;31m]"
if [ `id -u` != "0" ]; then
PS1="${GREEN}u${CYAN}@${GREEN}h ${CYAN}w${WHITE} ${default}$ "
else
PS1="${RED}u${CYAN}@${GREEN}h ${CYAN}w${WHITE} ${default}$ "
fi
bash_prompt
### COLORIZE PACMAN (PACS)
pacsearch () {
echo -e "$(pacman -Ss $@ | sed
-e 's#current/.*#\033[1;31m&\033[0;37m#g'
-e 's#extra/.*#\033[0;32m&\033[0;37m#g'
-e 's#community/.*#\033[1;35m&\033[0;37m#g'
-e 's#^.*/.* [0-9].*#\033[0;36m&\033[0;37m#g' )"
This is really pretty basic.  I use the same ~/.bashrc for all users, including root...
The alias section is pretty self explanatory, basically the parts in quotations (" ") get run instead of the commands before the equals (=) in every case.
The bash prompt section is a bit nifty.  The first part, with color definitions, is so that I don't go mad trying to write the actual PS1 line.  Makes it cleaner in my opinion.  There's lots of documentation out there if you're interested in modifying the prompt I have.
The if/then/else statement in the bash prompt section checks if the user is root.  If not, the username is displayed in GREEN at the prompt.  If the user is root, the username is displayed in RED.  A nice visual reminder, and since I use my ~/.bashrc for ALL users, including root, it helps make the file more portable.
The last section is taken straight from the Arch wiki.  At the top I aliased 'pacs', which calls this section.  Basically 'pacs' can take the place of 'pacman -Ss' and offer simple colour output.
http://wiki.archlinux.org/index.php/Col … man_output
Additions, other bash tips & tricks, comments, all welcome

Answer 1

I added some comments explaining each piece.
Misc stuff:
# My prompt, quite basic, decent coloring, shows the value of $?
# (exit value of last command, useful sometimes):
C_DEFAULT="[33[0m]"
C_BLUE="[33[0;34m]"
export PS1="$C_BLUE($C_DEFAULT$?$C_BLUE)[$C_DEFAULTu$C_BLUE@$C_DEFAULTh$C_BLUE:$C_DEFAULTw$C_BLUE]\$ $C_DEFAULT"
export PS2="$C_BLUE> $C_DEFAULT"
# If you allow Ctrl+Alt+Backspace to kill the X server but are paranoid,
# then this alias will ensure that there will be no shell open afterwards.
alias startx="exec startx"
# Let grep colorize the search results
alias g="egrep --color=always"
alias gi="egrep -i --color=always"
# Hostname appended to bash history filename
export HISTFILE="$HOME/.bash_history_`hostname -s`"
# Don't save repeated commands in bash history
export HISTCONTROL="ignoredups"
# Confirm before overwriting something
alias cp="cp -i"
# Disable ^S/^Q flow control (does anyone like/use this at all?)
stty -ixon
# If your resolution gets fucked up, use this to reset (requires XRandR)
alias resreset="xrandr --size 1280x1024"
And some small but handy functions:
# mkmv - creates a new directory and moves the file into it, in 1 step
# Usage: mkmv <file> <directory>
mkmv() {
mkdir "$2"
mv "$1" "$2"
# sanitize - set file/directory owner and permissions to normal values (644/755)
# Usage: sanitize <file>
sanitize() {
chmod -R u=rwX,go=rX "$@"
chown -R ${USER}.users "$@"
# nh - run command detached from terminal and without output
# Usage: nh <command>
nh() {
nohup "$@" &>/dev/null &
# run - compile a simple c or cpp file, run the program, afterwards delete it
# Usage: run <file> [params]
run() {
filename="${1%%.*}"
extension="${1##*.}"
file="$1"
shift
params="$@"
command=""
if [ $extension = "cc" -o $extension = "cpp" -o $extension = "c++" ]; then
command="g++"
elif [ $extension = "c" ]; then
command="gcc"
else
echo "Invalid file extension!"
return 1
fi
$command -Wall -o $filename $file
chmod a+x $filename
./$filename $params
rm -f $filename 2>/dev/null