Question

Recently i got an assignment at school, where we are to write a small program in Bash Scripting Language.

This shell script is supposed to accept some Positional Parameters or Arguments on the command line.

Now, with the help of an if-else statement i check if the argument is present, if the argument is present the script does what it is supposed to do, but if the argument is not present – i display an error message, prompting the user to input an argument and pass the argument again to the same shell script…

Now, i want to know if this approach is good or bad in Bash Programming paradigm. I’m slightly suspicious that this might run too many tasks in the background that are kept open or that are never ended and keep on consuming memory… please help.

Here’s a small snippet (assume the script name to be script1.bash):

 #!/bin/bash

 if [ $# -gt 0 ]; then
      read -p "Please enter your name: " name
      script1.bash $name
 elif [ $# -eq 1 ]; then
      echo "Your name is $1!"
 fi

Answer 1

It’s … questionable 🙂

The main problem is that you’re spawning a subshell everytime someone refuses to input their name.

You would be better of with something like:

#!/bin/bash
name=$1
while [[ -z "$name" ]] ; do
    read -p "Please enter your name: " name
done
echo "Your name is $name!"

which spawns no subshells.