Capture output of `time` utility
shell bash add tag
PeterVandivier 
Given `foo.sh` looks like this...

```bash
#!/bin/bash

echo good
echo bad 1>&2
```

... I can see how long it takes to run `foo.sh` by prefixing the [`time`](https://linux.die.net/man/1/time) utility.

```bash
time ./foo.sh

good
bad

real    0m0.003s
user    0m0.002s
sys     0m0.001s
```

I would like capture the output of `time` and log it to a file. Sadly neither redirection or capture appear to work as I expect.

![Screenshot 2020-09-23 at 08.58.15.png](/image?hash=8a6301b151e6efa50ff665b69a2310005f3d68adc630e8d539f1192908bb7c51)

Is there a naïve method to capture and log this output?

---

^n.b.^ ^Wrapping^ ^the^ ^command^ ^appears^ ^also^ ^to^ ^not^ ^work^ [^(screenshot)^](/image?hash=f1911dcade3262ca6df549e8e4f064ed9fe7fe936f1f3b3b62457fa024f9eff3)

^n.b.2^ ^coreutils^ ^`--output`^ ^arg^ ^appears^ ^to^ ^be^ ^screwing^ ^up^ ^for^ ^me^ ^as^ ^well^ [^(screenshot)^](/image?hash=018e88854b8e161d5e6b03ab850c4d9be040e48cdd20263b687ce045e82fe98a)
Top Answer
Jack Douglas 
As you imply, the [`time` command](https://linux.die.net/man/1/time) outputs the timing info to stderr:

> time writes a message to standard error giving timing statistics about this program run

However your redirection is happening to the output of `./foo.sh`, not the output of `time`.

To force that you can use braces:

```
# { time ./foo.sh; } &> foo.log 
# cat foo.log 
good
bad

real	0m0.005s
user	0m0.001s
sys	0m0.005s
```

---

*Side note*: you are using the Bash built-in version of `time`:

::: tio S0oszvj/v6SyIFWhJDM39f9/AA
§§§ bash bash
type time
§§§
``` none
time is a shell keyword
```
:::

There is also [a GNU version](https://www.gnu.org/software/time/) with various options and a different default output format.
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