I have found that a systems administrators job doesn't simply involve managing services and ensuring they are running. Many times the job includes extracting data from files and putting them into a usable form.
Today's example of Shell-Fu is creating a CSV list of the users on the system generated by the /etc/passwd file.
[[email protected] play]$ cat /etc/passwd | cut -d: -f1| perl -pi -e 's/n/,/' root,bin,daemon,adm,lp,sync,shutdown,halt,mail,uucp,operator,games,[Continued]
If you wanted to save this to a file you could use
> or depending on whether you want to overwrite pre-existing data or not.
> Will overwrite an existing file
>> Will append to an existing file