BASH Shell: How To Redirect stderr To stdout ( redirect stderr to a File )

by VIVEK GITE on MARCH 12, 2008 

Q. How do I redirect stderr to stdout? How do I redirect stderr to a file?

A. Bash and other modern shell provides I/O redirection facility. There are 3 default standard files (standard streams) open:
[a] stdin – Use to get input (keyboard) i.e. data going into a program.

[b] stdout – Use to write information (screen)

 stderr – Use to write error message (screen)

Understanding I/O streams numbers

The Unix / Linux standard I/O streams with numbers:

Handle Name Description
0 stdin Standard input
1 stdout Standard output
2 stderr Standard error

Redirecting the standard error stream to a file

The following will redirect program error message to a file called error.log:

$ program-name 2> error.log
$ command1 2> error.log[/code]

Redirecting the standard error (stderr) and stdout to file

Use the following syntax:

$ command-name &>file[/code]

$ command > file-name 2>&1[/code]
Another useful example:

# find /usr/home -name .profile 2>&1 | more[/code]

Redirect stderr to stdout

Use the command as follows:

$ command-name 2>&1[/code]

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