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Redirect all output to file


Question

I know that in Linux, to redirect output from the screen to a file, I can either use the > or tee. However, I'm not sure why part of the output is still output to the screen and not written to the file.

Is there a way to redirect all output to file?

2015/03/03
1
761
3/3/2015 3:42:41 PM

Accepted Answer

That part is written to stderr, use 2> to redirect it. For example:

foo > stdout.txt 2> stderr.txt

or if you want in same file:

foo > allout.txt 2>&1

Note: this works in (ba)sh, check your shell for proper syntax

2011/07/13
1206
7/13/2011 5:10:01 AM

All POSIX operating systems have 3 streams: stdin, stdout, and stderr. stdin is the input, which can accept the stdout or stderr. stdout is the primary output, which is redirected with >, >>, or |. stderr is the error output, which is handled separately so that any exceptions do not get passed to a command or written to a file that it might break; normally, this is sent to a log of some kind, or dumped directly, even when the stdout is redirected. To redirect both to the same place, use:

command &> /some/file

EDIT: thanks to Zack for pointing out that the above solution is not portable--use instead:

*command* > file 2>&1 

If you want to silence the error, do:

*command* 2> /dev/null
2014/10/23

To get the output on the console AND in a file file.txt for example.

make 2>&1 | tee file.txt

Note: & (in 2>&1) specifies that 1 is not a file name but a file descriptor.

2017/05/28

Use this - "require command here" > log_file_name 2>&1

Detail description of redirection operator in Unix/Linux.

The > operator redirects the output usually to a file but it can be to a device. You can also use >> to append.

If you don't specify a number then the standard output stream is assumed but you can also redirect errors

> file redirects stdout to file
1> file redirects stdout to file
2> file redirects stderr to file
&> file redirects stdout and stderr to file

/dev/null is the null device it takes any input you want and throws it away. It can be used to suppress any output.

2015/06/11

Credits to osexp2003 and j.a. …


Instead of putting:

&>> your_file.log

behind a line in:

crontab -e

I use:

#!/bin/bash
exec &>> your_file.log
…

at the beginning of a BASH script.

Advantage: You have the log definitions within your script. Good for Git etc.

2020/04/19

You can use exec command to redirect all stdout/stderr output of any commands later.

sample script:

exec 2> your_file2 > your_file1
your other commands.....
2015/10/10

Source: https://stackoverflow.com/questions/6674327
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