I'm trying to find a way to determine the difference between two strings in my script. I could easily do this with diff or comm, but I'm not dealing with files and I'd prefer not to output them to files, do the compare and read it back.
I see that comm, diff, cmp all allow to pass either two files OR a file and standard input - I guess that's good if I don't want to output two files...but it's still kinda sucks.
Been digging around thinking I can use grep or regular expressions - but I guess not.
Using diff or com or whatever you want:
diff <(echo "$string1" ) <(echo "$string2")
Greg's Bash FAQ: Process Substitution
or with a named pipe
mkfifo ./p
diff - p <<< "$string1" & echo "$string2" > p
Greg's Bash FAQ: Working with Named Pipes
Named pipe is also known as a FIFO.
The - on its own is for standard input.
<<< is a "here string".
& is like ; but puts it in the background