How to get both the output of the time command in a file?

Question

I ran the command time echo "Hello world" | tee output.txt expecting to get the full output to both terminal stdout and the output.txt file. However, the file content is not what I expect :

Expected file content:

Hello world

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

Actual content:

Hello world"

can anyone help ?

[How can I redirect the output of 'time' to a variable or file?](https://mywiki.wooledge.org/BashFAQ/032), *call `time` in a SubShell or block* is needed. — Rick, Jun 06 '22 at 10:06

score 9 · Accepted Answer · edited Jul 31 '20 at 17:03

9

time Writes the time statistics to stderr. So we need to redirect stderr stream into stdout, then redirect it's output to tee.

(time echo "Hello world") 2>&1 | tee output.txt

Here

we need to take (time echo) as a single command so used braces,
redirected stderr to stdout,
piped stdout to tee.

edited Jul 31 '20 at 17:03

Community

1

answered Jul 31 '20 at 04:06

turbulence

804
4
16

Yes, thank you. It worked – Ahmed Hussein Jul 31 '20 at 04:12
2

Those are really *parentheses* not braces, and cause the commands to be executed in a subshell. You can actually use braces instead, which avoids the subshell: `{ time echo "Hello world"; } 2>&1`. Note the whitespace and extra `;` which is necessary when written as a one-liner. – steeldriver Jul 31 '20 at 12:17
@steeldriver updated. – turbulence Jul 31 '20 at 16:17
... I didn't mean to imply that your original answer was incorrect - just that there's another way to do it (at least in bash) – steeldriver Jul 31 '20 at 16:23
@steeldriver ok – turbulence Jul 31 '20 at 16:24
it's not working – dome Mar 16 '23 at 17:46
@dome, what system you are using. Still working on my computer. – turbulence Mar 18 '23 at 10:48

How to get both the output of the time command in a file?

1 Answers1