Bash script for switching branches in Git

This script follows my workflow of switching between different branches in my dev environment:
1. Stash changes in my current branch.
2. Checkout the other branch.
3. Apply previously saved stash on the switched branch.

#!/bin/bash

echo "Switching to $1 branch..."
BRANCH=$(git branch | grep \* | cut -d ' ' -f2)
STASHNAME="$BRANCH-changes"
git stash save "$STASHNAME"
git checkout $1
LATEST=$(git stash list | grep $1 | head -n 1)
echo "Latest stash: $LATEST"
echo "Do you want to apply this stash? [y/n]: "
read apply_stash
if [ "$apply_stash" == "y" ]; then
    STASHED=$(git stash list | grep $1 | head -n 1 | cut -d ":" -f1)
    git stash apply "$STASHED"
fi

Change bash command prompt in Debian

Followed this post

$ vi /etc/bash.bashrc
Add this at the end:

# If id command returns zero, you have root access.
if [ $(id -u) -eq 0 ];
then # you are root, set red colour prompt
   PS1="\\[$(tput setaf 1)\\][\\u@\\h:\\w] (apps)# \\[$(tput sgr0)\\]"
else # normal
   PS1="[\\u@\\h:\\w] (apps)$ "
fi

Bash Cheat Sheet

1. Run a script with no output and in the background
$ ./my_script.sh > /dev/null 2>&1 &

2.  Run a script with no output and in the background and see the pid
$ ./my_script.sh > /dev/null 2>&1 & echo $!

3. Template script that loops thru and writes to a file
#!/bin/bash

# $1 - number of minutes
# $2 - task id
COUNTER=$(($1*60/5))
TOTAL=$COUNTER
echo Perfload will run for $1 minutes
echo "Perfload will run for $1 minutes" > /tmp/$2.log
until [  $COUNTER -eq 0 ]; do
    echo The counter is $COUNTER
    PROGRESS=$(echo "scale=2;($TOTAL - $COUNTER)*100/$TOTAL" | bc -l)
    echo "Perfload RUNNING $PROGRESS %" >> /tmp/$2.log
    let COUNTER-=1
    sleep 5
done
echo "Perfload SUCCESS" >> /tmp/$2.log

My .aliases

My collection of bash knick knacks.

alias 2proj='cd /auto/home/samdc/projects'

# cd to a directory that is relative to 2proj directory
function 2p() { 2proj && cd $@ ;}

# list resources files
# use: res filename*
function res() { 2proj && cd common/resources/ && ls -l */$@ ; }

# diff color
alias colorize='~/bin/p4c.rb'

Schedule rake using cron on rvm environment

Little tricky to get this going. The key is knowing rvm environment.

$ rvm env --path
/auto/home3/delacs/.rvm/environments/ruby-2.0.0-p353@RailsDev

For rvm, basic command line tools like gem, rake and ruby are in the wrappers directory.

$ crontab -l
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
HOME=/auto/home3/delacs
RAILS_ENV=development

0 7 * * * /bin/bash -l -c 'source ~/.bash_profile' && cd $HOME/Documents/projects/monweb_management && $HOME/.rvm/wrappers/ruby-2.0.0-p353@RailsDev/rake perfdb:get_baselines >> $HOME/logs/db.import.log 2>&1

5 7 * * * /bin/bash -l -c 'source ~/.bash_profile' && cd $HOME/Documents/projects/monweb_management && $HOME/.rvm/wrappers/ruby-2.0.0-p353@RailsDev/rake perfdb:get_published_runs  >> $HOME/logs/db.import.log 2>&1

Backup Dir and Files in Linux Using Tar and Bash

1. Create a bash script

$ vi backup.sh

#!/bin/bash
# This is a script the creates a backup of
# monitor instances: .../monitor/inst => .../monitor/backup

DATE=`date +"%Y%m%d"`
TIMESTAMP=`date +"%Y/%m/%d %T"`
FILENAME="inst_backup_$DATE.tar.gz"
SRCDIR="inst"
DESDIR="backup"

tar -cpzf $DESDIR/$FILENAME $SRCDIR

if [ $? -eq 0 ]; then
    echo "$TIMESTAMP: Backup success: $FILENAME"
else
    echo "$TIMESTAMP: Backup error: $?"
fi

# Any backup older than 30 days are deleted
find ./$DESDIR -type f -mtime +30 -delete -printf "$TIMESTAMP: Deleted %16f\n"

for tar:
c - create
p - preserve file and dir permission
z - compress file
f - target filename

2. Schedule with cron

$ crontab -e
0 5 * * * cd $HOME/scheduler/monitor && ./backup.sh >> $HOME/scheduler/monitor/backup/logs/monitor.backup.log 2>&1

This would schedule a backup at 5am everyday

Bash Keyboard Shortcuts

Ctrl + A        Go to the beginning of the line you are currently typing on
Ctrl + E        Go to the end of the line you are currently typing on
Ctrl + L        Clears the Screen, similar to the clear command
Ctrl + U        Clears the line before the cursor position. If you are at the end of the line, clears the entire line.
Ctrl + H        Same as backspace
Ctrl + R        Let’s you search through previously used commands
Ctrl + C        Kill whatever you are running
Ctrl + D        Exit the current shell
Ctrl + Z        Puts whatever you are running into a suspended background process. fg restores it.
Ctrl + W        Delete the word before the cursor
Ctrl + K        Clear the line after the cursor
Ctrl + T        Swap the last two characters before the cursor
Esc + T         Swap the last two words before the cursor
Alt + F         Move cursor forward one word on the current line
Alt + B         Move cursor backward one word on the current line
Tab             Auto-complete files and folder names