which programs will the killall command kill?

Question

How do I list which programs will be killed with a killall command before I run it?

I'm looking for a killall -dryrun java kind of command, which would list all java processes that would be killed by executing the killall java command.

Answer 1

You can use pgrep as follows to list the processes first:

pgrep -a java

Answer 2

Depending on the killall version used on your system killall -s might do the trick. E.g. this is the case at least on Mac OS X and FreeBSD

On other variants of killall -s SIGNAL is used to specify the signal to send. Killall is not part of UNIX/POSIX standard so implementations vary.