Stderr, also known as standard error, is the default file descriptor where a process can write error messages. In Unix-like operating systems, such as Linux, macOS X, and BSD, stderr is defined by the POSIX standard. … In the terminal, standard error defaults to the user’s screen.

What is stderr used for?

Stderr is the standard error message that is used to print the output on the screen or windows terminal. Stderr is used to print the error on the output screen or window terminal. Stderr is also one of the command output as stdout, which is logged anywhere by default.

What is stderr and stdout in Linux?

The Linux Standard Streams

Text output from the command to the shell is delivered via the stdout (standard out) stream. Error messages from the command are sent through the stderr (standard error) stream. So you can see that there are two output streams, stdout and stderr , and one input stream, stdin .