Introduction to Unix |
|
|
|
See also
4.5. File Redirection¶
As was discussed in Standard Files and File Descriptors, standard input, output and error (stdin, stdout, stderr) are open file descriptors in every process.
4.5.1. stdin Redirection¶
Redirect standard input from a file (instead of the keyboard) using the
< metacharacter.
$ command < file
4.5.2. stdout Redirection¶
Redirect standard output to a file (instead of the terminal) using the
> metacharacter. The >> metacharacter redirects stdout appending
the file.
$ command > file
$ command >> file
4.5.3. stderr Redirection¶
Redirect standard error (error messages) to a file (instead of the terminal)
using the 2> metacharacter. The 2>&1 metacharacter redirects stderr
to the same file that stdout was redirected to.
# stdout to terminal and stderr to file:
$ command 2> file
# stdout and stderr to different files:
$ command > out_file 2> error_file
# stdout and stderr to the same file:
$ command > file 2>&1
