Redirect all output to file
I know that in Linux, to redirect output from the screen to a file, I can either use the
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?
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
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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
|. 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
To get the output on the console AND in a file
file.txt for example.
make 2>&1 | tee file.txt
2>&1) specifies that
1 is not a file name but a file descriptor.
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.
Credits to osexp2003 and j.a. …
Instead of putting:
behind a line in:
#!/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.
You can use
exec command to redirect all stdout/stderr output of any commands later.
exec 2> your_file2 > your_file1 your other commands.....