Displaying stdout to screen and file, stderr only to file

jeriryan · 07-11-2013, 10:26 AM

Hi guys,

I'm trying to figure out how I can have the stdout from my script print to the screen and a log file, and have stderr print only to the log file. And if possible, have it sequenced correctly (since I've read that because of stdout and stderr being handled by buffers differently, ordering might be rearranged).

Anyone know how I can accomplish this?

AlucardZero · 07-11-2013, 10:51 AM

What kind of script? If this is a shell script, use redirection and tee (man tee) as follows:

Code:

./foo 2>/tmp/errorlog | tee /tmp/screenlog

edit: this will send STDOUT and STDERR to different files which is not exactly what you asked, but I don't see a button to delete my post.

smallpond · 07-11-2013, 10:59 AM

The problem is that piping stdout to tee (or anything else) delays stdout so you lose ordering. Combining the outputs preserves order but doesn't let you send them to different places. AlucardZero's solution seems like the best you can do.

shm0 · 07-12-2013, 03:18 AM

Quote:

Originally Posted by jeriryan

Hi guys,

I'm trying to figure out how I can have the stdout from my script print to the screen and a log file, and have stderr print only to the log file. And if possible, have it sequenced correctly (since I've read that because of stdout and stderr being handled by buffers differently, ordering might be rearranged).

Anyone know how I can accomplish this?

You can use the stdbuf utility, here is an example.