Bash Commands

bash_commands.sh

#!/usr/bin/env bash

# split strings
GIT_BRANCH="origin/master"
remote=`echo $GIT_BRANCH |  cut -d '/' -f 1`
branch=`echo $GIT_BRANCH |  cut -d '/' -f 2`

# finding working directory of a process (where $$ is the PID, obtained through `pgrep` or other)
pwdx $$
# or
lsof -p $$ | grep cwd
# or
readlink -e /proc/$$/cwd #This one seems to give the exact value needed

# replace strings in a file - Mac OS X
sed -i '' -e 's/STRING_TO_REPLACE/NEW_STRING/g' filename

# show all network interfaces
ifconfig -a

# Check if variable is empty
if [ -z "$var" ]; then
  echo "Variable not provided"
  exit 1
fi

# Check if directory does not exist.
if [ ! -d "$dir" ]; then
  echo "Directory $dir does not exist!"
  exit 1
fi

# Check if file exists.
FILE=/etc/resolv.conf
if [ -f "$FILE" ]; then
    echo "$FILE exists."
fi

# Create a tar file without absolute directories.
# '-C' specifies the directory to switch to before packing. 
tar -zcf /tmp/deploy.tar.gz -C deploy .

# Get directory of current script.
SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"

# See all open ports.
sudo lsof -i -P -n | grep LISTEN

# Check what's running on a specific port.
sudo lsof -i:53 #replace 53 by any other port.

# Print 1st column of output
echo foo bar baz | awk '{print $1}'

ubuntu.sh

#!/usr/bin/env bash

# Enable automatic login.
sudo sed -i -e 's/#  AutomaticLoginEnable = true/AutomaticLoginEnable = true/g' /etc/gdm3/custom.conf
sudo sed -i -e 's/#  AutomaticLogin = user1/AutomaticLogin = vagrant/g' /etc/gdm3/custom.conf