BASH: exit command in while loop (doesn't work?)

[sha1sum]

Here is the problem I have:

Say we have a the file instruments.txt


guitar
piano
violin
cello
trumpet
ukelele



Now we do the following


#!/bin/bash

cat instruments.txt | while read; do
if [[ $REPLY =~ trumpet ]]; then
echo "trumpet is not a stringed instrument!"
exit 1
else
echo $REPLY
fi
done

echo "All are stringed instruments" # last line of the program


I expected that upon reading the line "trumpet", the program would exit. So the output should look like this:

guitar
piano
violin
cello
trumpet is not a stringed instrument!


However, the output I get is the following


guitar
piano
violin
cello
trumpet is not a stringed instrument!
All are stringed instruments

So what seems to happen is that the exit command doesn't exit the program, but only the loop. After that, the rest of the program is still executed.

How can I make the exit command exit the entire program?

[sha1sum]

Maybe worth mentioning that I could work around it by doing the following:


#!/bin/bash

varex=

cat instruments.txt | while read; do
if [[ $REPLY =~ trumpet ]]; then
echo "trumpet is not a stringed instrument!"
varex=1
exit 1
else
echo $REPLY
fi
done

if [[ -n varex ]]; then
exit
fi

echo "All are stringed instruments"



Then it does work properly, but I don't really consider that a solution, but rather an ugly work-around. The exit command is behaving like the break command, which is not what I want it to do.

[steeldriver]

Is the catch that, by piping into the while loop from a cat command you are implicitly spawning a subshell, and it is that shell that is being exited? How about



while read; do
if [[ $REPLY =~ trumpet ]]; then
echo "trumpet is not a stringed instrument!"
exit 1
else
echo $REPLY
fi
done < instruments.txt

[sha1sum]

EDIT: I tried that and it works. Thanks!

I also think that it's some kind of subshell being exited instead of the entire program.

EDIT2: This solution also works on the bigger program I was writing (the one with the musical instruments was purely for illustration), so I'm out of the woods for now. :D

I'm leaving the topic open to see if somebody has another way of fixing it. There has to be a way to exit the program, even if the while-read loop is reading from a pipeline.