I was using fish-shell when reading about kill command.
The output of kill -l command for fish is
HUP INT QUIT ILL TRAP ABRT IOT BUS FPE KILL USR1 SEGV USR2 PIPE ALRM
....
When invoking same command in bash I had
1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP
....
I checked kill with whereis, and there is valid path to program /usr/bin/kill. I also checked man bash for kill, and didn't find anything connected to kill itself :(, so it's not bash builtin.
I also tried kill -l on tcsh and output was once more different.
This is not very important problem for me, but I really curious why does it look like this.
I'm using RHEL7 clone.
Best Answer
It can still be a shell built-in even when not documented:
With fish:
With zsh
With tcsh
It is a built-in for dash also, but the listing is a single column...
I would get similar results for other systems (the nice thing about portable code). As for
whereis
, the manual page saysnote the binary (it does not try to look for shell built-ins or aliases).