This is an old revision of the document!
Use Input-output Redirection
General Information
Using input/output redirection (>, », |, 2>, etc.).
> Redirect standard output to a file, overwrite contents
cat /etc/system-release > info.txt
» Redirect standard output to file, append to file
tail /etc/passwd >> info.txt
| Piping output to other commands
cat /etc/passwd | wc -l
Count the number of lines in /etc/passwd
2> Redirect standard error
ssh admin@webserver01.com "uptime" 2>/dev/null
SSH to webserver01.com, issue the uptime command, send standard errors to /dev/null (to nowhere)
Redirect both standard error and standard output
ssh admin@webserver01.com "uptime" &> results.log
Redirect standard error to standard out
cat /etc/system-release /etc/Red 2>&1 | grep Red
Standard output can be passed through a pipe to the next command. By redirecting standard error to standard output, any error messages are successfully sent through as well.