time nohup ./script --> the time hasn't been logged

Question

I need to measure the time that Firefox takes to build itself from the source code. Here's what I do normaly:

nohup ./mach build > my_log.log &

I then prepended time to it:

time nohup ./mach build > my_log.log &

However, this hasn't made it generate any report about the time spent, at the end of the my_log file.

Why not? How to fix it?

this might be smarter: `nohup time -o build.out ./mach build >my_log.log 2>&1 &` the output from `time` is in build.out/, ( or even add `--verbose` after the `-o build.out` ) — Luuk, May 27 '23 at 16:40

Romeo Ninov · Answer 1 · 2023-05-27T20:21:02.110

1

In your second attempt you measure the execution time of nohup command itself. So to get the build time you should put time after nohup:

nohup time ./mach build >my_log.log  2>&1 &

Also redirect the STDERR is good practice.

And as mentioned in comment you can have dedicated log for time command:

nohup time -o build.time ./mach build >my_log.log  2>&1 &

edited May 27 '23 at 20:21

answered May 27 '23 at 19:45

Romeo Ninov

1 Answers1