How do i use the if/else conditional statements in bash shell scripts?

vaquitasos

The structure of the if/else conditional statements is as follows:

if condition; then 
   action 
else  
   action 
fi

Go back to the How do i use the if conditional statements in bash shell scripts? article. We will add the else condition to this script; to work out the disk usage of a directory. Note: You need read permissions to the directory you use in this example.

if [ $# -lt 1 ];then
   echo "You must specify a directory name"
   echo "Usage: $0 <directoryname>"
   exit 1
else
   du -sh $1
fi

Running the script.

$ ./dirsize.sh /home/trainer/bin
26M	/home/trainer/bin