Standard Stream Redirection

The standard streams are normally associated with the console. The command will print to the terminal, or will read input typed into the terminal. Stdin and stout can also be redirected to write to or read from a file.

Redirect standard input with <

$./mycode < params.txt

Redirect standard output with >

$ls –l > filelist.txt 

If the file exists, > will overwrite it. Append with >>.

$cat file1 >> bigfile.csv

Redirection of standard error depends on the shell and is needed for only a few commands.

For bash

$make >& make.out

redirects both stdout and stderr from the make command to make.out.