How can I append text to a string in a file

HGeneAnthony · 02-27-2007, 11:56 AM

I was wondering if there's a way I can add text to a specific string in a file without opening it. For example, if I wanted to add a group to geneanthony in /etc/group is there a way I can search the file for any string with geneanthony in it and then append to the end ,users? Is there a way to append on the next line after a string so I can keep a file organized? For example, I like to put certain text near other text is this possible?

weibullguy · 02-27-2007, 12:11 PM

If I understand your questions, sed should do what you want. Here's a quick primer http://tldp.org/LDP/abs/html/x19673.html

HGeneAnthony · 02-27-2007, 02:31 PM

Thank you I'm looking it up now!

pixellany · 02-27-2007, 02:48 PM

You can't do anything to a file without opening it!!

To search for a specific string and add to it:

sed "s/string/stringplusnewstuff/g" <oldfile >newfile

Here is a good tutorial on SED

weibullguy · 03-01-2007, 12:16 PM

Code:

sed -i 's:geneanthony:&,users:g' /etc/group

will append the string ",users" to every instance of the string "geneanthony" in file /etc/group. All that redirect stuff creates new files and is unnecessary.