Re: unexpected bash behaviour

[Shaul Karl <shaulka@bezeqint.net>]

> How come `time a.out > /dev/null` prints "time" output,
> while `time (a.out > /dev/null)` doesn't print anything at all. 
> Shouldn't it be the other way around?
> 
> Thanks
> 
> Alec


[04:58:22 tmp]$ help time
time: time [-p] PIPELINE
    Execute PIPELINE and print a summary of the real time, user CPU 
time,
    and system CPU time spent executing PIPELINE when it terminates.
    The return status is the return status of PIPELINE.  The `-p' option
    prints the timing summary in a slightly different format.  This uses
    the value of the TIMEFORMAT variable as the output format.
times: times
    Print the accumulated user and system times for processes run from
    the shell.
[04:58:58 tmp]$ 


This explain the time a.out > /dev/null case. This is so because the 
whole string a.out > /dev/null is executed and its execution time is 
measured.

Do not know about time (a.out > /dev/null). It could be that time is 
forced to exit as soon as a sub shell is forked and so it can not 
measure the execution time of the sub process.

-- 

    Shaul Karl
    email: shaulka(at-no-spam)bezeqint.net 
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