Shell Redirections ↔ Quick Guide

File descriptors:
stdin : 0
stdout : 1
stderr : 2
Redirecting stdin
This trick can be used to take multi-line input in scripts.
#!/usr/bin/env bash
​
echo -e "Enter Commit Message (Ctrl+d when done):"
msg=$(</dev/stdin)
echo $msg
Redirecting stderr
1.Use 2>. Compatible with both bash and sh
Redirecting both stderr & stdout
1.With bash, use some_command &> /dev/null
2.With sh,
some_command > where-to-redirect 2>&1
# or
some_command 2>&1 > stdout_and_err
3.If you want to capture standard output/error separately,
$ some_command 1>output.txt 2>error.txt

Last modified 1yr ago

Shell Redirections ↔ Quick Guide

Redirecting `stdin`

Redirecting `stderr`

Redirecting both `stderr` & `stdout`