How can I redirect the output of the “time” command?

Question

I tried to redirect the output of the time command, but I couldn\'t:

$time ls > filename
real    0m0.000s
user    0m0.000s
sys     0m0.000s

Answer 1

The reason why redirection does not seem to work with time is that it's a bash reserved word (not a builtin!) when used in front of a pipeline. bash(1):

If the time reserved word precedes a pipeline, the elapsed as well as user and system time consumed by its execution are reported when the pipeline terminates.

So, to redirect output of time, either use curly braces:

{ time ls; } 2> filename

Or call /usr/bin/time:

/usr/bin/time ls 2> filename