Is there a way to pipe output of time command into a log file?

Question

I want to pipe the output of time command rather than the output of the job it is measuring the time of. I tried

 /usr/bin/time -v java RandomTest > time.log

But that redirects java RandomTest's output to time.log

possible duplicate of [how can't I redirect the output of time command](http://stackoverflow.com/questions/2408981/how-cant-i-redirect-the-output-of-time-command) — Simon, Dec 13 '12 at 04:01

score 4 · Answer 1 · answered Dec 12 '12 at 22:34

4

This one is a bit tricky, but you can do it as follows:

{ time java RandomTest ; } 2> time.log

This way the result of time goes into time.log, and stdout from java RandomTest stays in your tty.

Try it first with:

{ time ls ; } 2> tmp.txt 

cat tmp.txt

answered Dec 12 '12 at 22:34

sampson-chen

score 3 · Accepted Answer · answered Dec 12 '12 at 21:43

3

At least on recent Linux distributions, the time command supports the -o FILE option:

/usr/bin/time -v -o time.log java RandomTest

answered Dec 12 '12 at 21:43

kanaka

Basile Starynkevitch · Answer 3 · 2012-12-13T06:03:53.127

1

You could redirect also the stderr e.g. with >& in bash or zsh

(the >& is the same as 2>&1 since its redirects stderr to stdout)

edited Dec 13 '12 at 06:03

answered Dec 12 '12 at 21:40

Ah I suspected time might be writing to stderr and tried `time -v java RandomTest 2 > time.log` with no avail. I'm not familiar with the `>&` construct. How is `>& time.log` different from `2 > time.log`? – fo_x86 Dec 12 '12 at 21:48
@fo_x86 : Not sure if you have a typo there, but its `2> time.log` (not space). Good luck. – shellter Dec 12 '12 at 22:09
Thanks for pointing that out. Yes it was a careless typo. – fo_x86 Dec 12 '12 at 22:17

3 Answers3