Script that does not change itself

Shell Programming and Scripting
1

I have a script that makes inline replacements to other scripts in a given directory: it loops through all files with extension "sh". What is a standard way of preventing that the script does not change itself ($0)?

2

What utility is used to process your script (such as awk, sed, bash, or ksh)?

Show us the loop in your script that processes your *.sh files.

3

The file edited for brevity looks as follows:

for file in *.sh
do
   # identify file extension
   extension=${file##*.}
   
   # one space after the '#'
   sed -i '' -e 's/#/# /' $file
   sed -i '' -e 's/#  /# /' $file
done
4

should you be using bash (which Don Cragu asked for), extended pattern matching might work:

shopt -s extglob
for i in !(${0#*/}); do echo $i; done

EDIT: or some grep -v $0 in the for loop.

5

You could just exclude the running script file:

for n in *.sh; do
	if [[ "$n" != `basename $0` ]]; then
		echo $n
	fi
done
6

I like this solution because it requires a mere addition to the for loop without additional indentation:

7

As an alternative to the cool script solutions, could you simply name the script file different - not ending with .sh - or move it to a different directory?

8

Yes, I thought about that too. However, I felt the name change was too big a compromise, given that all other scripts have the sh or bash extension.
Moving to a different directory is not an option either, because one can never be sure that a copy of the script is going to end up in a directory which has sh or bash files in it.