How to get return code from a program in a new terminal? (BASH "Inception")

Question

In terminal I can easily grab the error code of a command

> cat thisdoesntexist
cat: thisdoesntexist: No such file or directory
> echo $?
1

But doing the same when I run the command in a new terminal

> gnome-terminal -e "cat thisdoesntexist"
> echo $?
0

How can I grab the error code of the command in the second case (so that it returns 1)?

Answer 1

You probably have to rely on a fifo to communicate between the two shells as gnome-terminal does not seem to propagate exit status.

sh$ TMPDIR=$(mktemp -d)
sh$ F=$TMPDIR/fifo
sh$ mkfifo $F
sh$ gnome-terminal -e 'bash -c "cat thisdoesntexist; echo $? > '"$F"'"'
sh$ cat $F
1
sh$ rm -rf $TMPDIR 

Please notice: Fifo have the added benefit of being blocking. You might use regular file for simplicity, but beware of possible race conditions.