Bash Shell: Check for optional arguments

One day, I got sick of typing up the whole command over and over.

I needed to write a script that took in one mandatory argument and a second optional argument.

To make the second argument optional, use the "-z" operator checks if a string is empty. The "-n" operator checks for the string being not empty.

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01.if [ -z "$1" ]; then

02.  echo "You need at least 1 argument"

03.  exit 1

04.fi

05. 

06.if [ -z "$2" ]; then

07.  DOMAIN=$1

08.else

09.  DOMAIN=$2

10.fi

11. 

12.CMD="command something $1 -some -flags $DOMAIN"

13.echo $CMD

14.$CMD

Remember to "chmod +x filename" to make it executable.

Now you can begin performing all crazy sorts of bash-fu.

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