Unix Shell Redirection ====================== Three built-in files/streams usable for redirection: STDIN (handle 0) STDOUT (handle 1) STDERR (handle 2) Standard **output** redirection operators: > (right carrot) (create/overwrite) $ ls . > file_list.txt | (pipe) $ cat file_list.txt | sort | less >> (double carrot) (append) $ ls ./foo/ >> file_list.txt Standard **input** redirection operators: < (left carrot) $ sort < file_list.txt Redirecting both input and output: $ sort < file_list.txt > sorted_file_list.txt < implicitly refers to STDIN, while > implicitly referes to STDOUT. Redirect standard error into standard out: $ make all 2>&1 | less Redirect error to null: $ make all 2>/dev/null | less Redirect both STDOUT and STDERR to null: $ rm -f $(find / -name core) &> /dev/null