$ which time
time: shell reserved word
$ ls /usr/bin/time /bin/time
ls: cannot access '/usr/bin/time': No such file or directory
ls: cannot access '/bin/time': No such file or directory
Which gives new meaning to the relativity and vagueries of time....
$ time ls / bin boot dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
real 0m0.004s
user 0m0.000s
sys 0m0.000s
$ /usr/bin/time ls /
bin boot dev etc home lib lib64 lost+found media mnt opt proc root run sbin srv sys tmp usr var
0.00user 0.00system 0:00.00elapsed 0%CPU (0avgtext+0avgdata 2304maxresident)k
0inputs+0outputs (0major+109minor)pagefaults 0swaps
Edit: formatting
GNU source: http://git.savannah.gnu.org/cgit/time.git/tree/
BSD source: https://github.com/freebsd/freebsd/blob/f5d95e1f8d32db4ccccf...
Busybox source: https://github.com/mirror/busybox/blob/f88e3bfa8ded4f1c7e7d2...
Toybox source: https://github.com/landley/toybox/blob/master/toys/posix/tim...
This would have been a lot easier if I'd known GitHub has a `filename:` search