Suggestion, Implement "time"

[etu]

Like in bash:

$ time <do something that takes time>
...

real 0m0.000s
user 0m0.000s
sys 0m0.000s
$

[maxfl]

time should not be implemented, because it's a system util
in arch/debian/ubuntu it is in the package 'time'

[etu]

I can say it's built-in in bash. But, found package in gentoo too, so I guess that's fine.

[justinmayer]

I think @etu might be onto something. As far as I can tell, the time command doesn't work with fish functions, at least on Mac OS X 10.8.2:

~> time myfishfunction
myfishfunction: No such file or directory

The time command produces the expected behavior when running an equivalent bash function. Unless I'm missing something, I think perhaps this should indeed be investigated further.

[JanKanis]

It would be nice for this to work, but that requires making a builtin time. Labeling this as an enhancement for fish-future

[terlar]

👍

[uggedal]

If you need to time fish functions:

time -p fish -c 'chemical_element_to_symbol oxygen'
o
real 0.03
user 0.00
sys 0.02

[etu]

Yes, that probably works. But does not produce a fair result. Because launching another instance of the shell means overhead.

So in theory, timing of all fish-functions would be equally slow (if you can trust that fish always takes the same time to launch). Which might not be true since we all do have different configs, different hardware, and stuff. I for instance set my own $PATH in fish-config, which not only sets a variable, it also checks for duplicates in the variable, and so on.

We would have a better result with better performance if we had a builtin for it.

And @uggedal, Your hack is a fine hack, so I rewrote my function "time" to use it. I made a function because I always want -p on the command to be there.

function time --description 'Wrapper for time'
    /usr/bin/time -p /bin/fish -c $argv
end

Because time is... well, time-sensitive, having a builtin for it might actually make sense. That conceptually works but has some overhead in loading another fish process.

[tom-pang]

+1 on this. Not being able to accurately time builtin functions is frustrating

[mrak]

👍 I'd love it for making my complicated prompt functions faster

[nsmgr8]

The custom time function that wrap the /usr/bin/time is not a good solution for me. It creates a new shell that does not have the current environment. Hence certain types of command will fail. For example, a python script that is running from a virtualenv.