`time` crashes in a script

[Calil Neto]

In a script, when I run `time` like this:

$TIME=`time $cmd`

It runs well, but when I put the time in a variable

cmd="time cmd"
$TIME=`$cmd`

It apparently crashes.

This is a testcase where it works:
$ cmd="ls"; time $cmd
(ls output)

real 0m0.003s
user 0m0.000s
sys 0m0.004s

And in this case it crashes:
$ cmd="time ls"; $cmd
(ls output)
0.00user 0.00system 0:00.00elapsed 200%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+292minor)pagefaults 0swaps

[IKT (ikt)]

ikt@ikt-desk:~$ cmd="time ls"; $cmd
Dropbox Music Templates
0.00user 0.00system 0:00.00elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+305minor)pagefaults 0swaps
ikt@ikt-desk:~$ uname -a
Linux ikt-desk 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:05:01 UTC 2009 x86_64 GNU/Linux
ikt@ikt-desk:~$

Confirming this bug in ubuntu 9.10.

[IKT (ikt)]

Talked about this on irc and Pici noted something:

Its just using the default time output format, instead of the one that it regularly uses. The manpage says that it should use the following format if none is specified:

%Uuser %Ssystem %Eelapsed %PCPU (%Xtext+%Ddata %Mmax)k
%Iinputs+%Ooutputs (%Fmajor+%Rminor)pagefaults %Wswaps

It looks like it has to do with an environment variable, but its not $TIME even though the manpage says it should be.

If I run time from within dash, it gives me that extended output.
--
So it doesn't appear to be a problem with the command as such, but it's not working as intended.

[Jilles Tjoelker (jilles)]

This is because bash's time is a keyword, not a builtin command ('type time' will show). Therefore it will only be recognized if it is in the input literally and unquoted.

[IKT (ikt)]

setting to invalid since there is essentially nothing to fix.