Linux Shell Command - Find And Replace Text Within Files

To Find and Replace text within file(s)

ok today i was asked to edit 900 files in a unix system. i was asked to change the ip addresses on all the dns records in bind.

so when i went to see how many domain names there were, there were like 980 pri. files.. ouch

how am i going to do this.. do i have to do this one by one? no, i thought, there's gotta be an easier way tot do this. well im luck because you can search for text and then replace whatever text you want in a file with some simple commands in linux.

so here is my situation. when i open a pri. file in /var/named/chroot/var/named/pri.mydomain.com it looks something like this:

pri.mydomain.com

$TTL        86400
@       IN      SOA     ns1.webune.com. admin.mydomain.net. (
                        2006101601       ; serial, todays date + todays serial #
                        28800              ; refresh, seconds
                        7200              ; retry, seconds
                        604800              ; expire, seconds
                        86400 )            ; minimum, seconds
;
                NS      ns1.webune.com.              ; Inet Address of name server 1
                NS      ns1.webune.com.              ; Inet Address of name server 2
;

www  MX      10 ns1.webune.com.

mydomain.net.      A        192.168.1.135
www       A       192.168.1.135

;;;; MAKE MANUAL ENTRIES BELOW THIS LINE! ;;;;

as you can see my pri files have 192.168.1.135 address, so i want to change it to 192.168.1.112

so i would use these commands for the shell to go look in all my pri file where it find 192.168.1.135 and replace it with 192.168.1.112

Command:

for fl in pri.*; do
mv $fl $fl.old
sed ’s/192.168.1.135/192.168.1.112/g’ $fl.old > $fl
done

This command will make backup copies of the old files

Command WITHOUT MAKING BACKUPS:

for fl in pri.*; do
mv $fl $fl.old
sed ’s/192.168.1.135/192.168.1.112/g’ $fl.old > $fl
rm -f $fl.old
done

so now when i view the file called pri.mydomain.com it looks like this:

pri.mydomain.com

$TTL        86400
@       IN      SOA     ns1.webune.com. admin.mydomain.net. (
                        2006101601       ; serial, todays date + todays serial #
                        28800              ; refresh, seconds
                        7200              ; retry, seconds
                        604800              ; expire, seconds
                        86400 )            ; minimum, seconds
;
                NS      ns1.webune.com.              ; Inet Address of name server 1
                NS      ns1.webune.com.              ; Inet Address of name server 2
;

www  MX      10 ns1.webune.com.

mydomain.net.      A        192.168.1.112
www       A       192.168.1.112

;;;; MAKE MANUAL ENTRIES BELOW THIS LINE! ;;;;

- that was easy

What do you think?