Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== Use Input-output Redirection ====== **General Information** Using input/output redirection (>, >>, |, 2>, etc.). ---- '>' Redirect standard output to a file, overwrite contents <code bash> cat /etc/system-release > info.txt </code> \\ '>>' Redirect standard output to file, append to file <code bash> tail /etc/passwd >> info.txt </code> \\ '|' Piping output to other commands <code bash> cat /etc/passwd | wc -l </code> * Counts the number of lines in /etc/passwd \\ '2>' Redirect standard error <code bash> ssh admin@webserver01.com "uptime" 2>/dev/null </code> * SSH to webserver01.com, issue the uptime command, send standard errors to /dev/null (to nowhere) \\ Redirect both standard error and standard output <code bash> ssh admin@webserver01.com "uptime" &> results.log </code> \\ Redirect standard error to standard out <code bash> cat /etc/system-release /etc/Red 2>&1 | grep Red </code> * 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. ---- linux_wiki/use_input-output_redirection.txt Last modified: 2019/05/25 23:50(external edit)