[TUHS] POSIX ed(1)'s exit status. (Was: diving into vi...)

Hi, Will Senn wrote: Me too. I've heard others who have told crontab(1) or their mail program to use ed have been bitten by the exit status varying between 0 and 1. ed(1p) explains: EXIT STATUS The following exit values shall be returned: 0 Successful completion without any file or command errors. This behaviour is surprising. Here's GNU ed: $ ed /tmp/foo /tmp/foo: No such file or directory a foo . wq 4 $ echo $? 0 $ ed /tmp/foo 4 /bar ? $a bar . wq 8 $ echo $? 1 $ I assume POSIX made it the default behaviour to be useful when ed isn't talking to mankind. Perhaps they think that's the default these days. GNU ed added -l: -l, --loose-exit-status exit with 0 status even if a command fails From https://man.netbsd.org/ed.1, I don't think BSD ed has a similar option. Probably, because it doesn't need it as my quick skim of http://bxr.su/NetBSD/bin/ed/main.c#220 suggests it will exit(0) even if an earlier search found nothing. There is a list of BSD's differences to POSIX, e.g. ‘z’ for scrolling, amidst the source, http://bxr.su/NetBSD/bin/ed/POSIX, but it doesn't mention the exit status. -- Cheers, Ralph.