length of time question

[TGrimace]

Is there a command in BASH that will show you how long the program took to execute? For example `echo $?` shows if the last command was successfully executed, isn't there somthing that tells how long it took?

[bwkaz]

Not directly, but if you look at the "time" command, it will probably do what you want. The difference is that using time, you have to know when you start that you want to time the program. If there was a bash variable, it wouldn't matter... hmm...

I'm pretty sure there isn't one, but it wouldn't be too hard to do, what with process accounting and all that...

[Stuka]

bwkaz: you were more right than you know (and so very wrong too! :P )
From the man page for time(1)The time command runs the specified program command with
the given arguments. When command finishes, time writes a
message to standard output giving timing statistics about
this program run. These statistics consist of (i) the
elapsed real time between invocation and termination, (ii)
the user CPU time (the sum of the tms_utime and tms_cutime
values in a struct tms as returned by times(2)), and (iii)
the system CPU time (the sum of the tms_stime and
tms_cstime values in a struct tms as returned by
times(2)).

[bwkaz]

Err, what?

Oh... when I said "there isn't one", I meant a bash variable or something like that. I know there's a "time" command... :D

[Stuka]

oooh...ok then...:D

[bwkaz]

Ooh! Idea! I could hack a variable that does do that into bash! When it fork()s off a process, it starts a timer (or something; I haven't thought this through all the way yet), then whenever a process ends, it sets the variable(s) to the different times... system, user, CPU, etc.

I wonder if anyone's thought of that before... hmm. In any case, I'd wait to start that until after Christmas. Too much work this semester in Real Life (or at least college).

[TGrimace]

Cool. I just figured out how to use the time command. The man pages are a bit misleading, but trial-and-error will always show the way, eventually. :D
Thanks guys!