Replacing strings in the middle of conf files

[lupo]

OK OK I am SUCH a newbie that I don't get it. I admit it!

Here is the situation.

Linux RHEL4.6

I want to disable "CTRL-ALT-DEL" in the /etc/inittab

I want to replace:
ca::ctrlaltdel:/sbin/shutdown -t3 -r now

With:
# Changed 8-5-08 -dfezz1 (disabling ctrl-alt-del at console)
ca:12345:ctrlaltdel:/bin/echo "CTRL-ALT-DEL is disabled"

I have tried the simplest SED I know:
$sed 's/replace_please/REPLACED_THX/g' /tmp/dummy
$sed 's/ca::ctrlaltdel:/sbin/shutdown -t3 -r now/ca:12345:ctrlaltdel:/bin/echo "CTRL-ALT-DEL is disabled"/g' /tmp/dummy

As you can tell from my feeble attempt, it didn't work, spaces and quotes seem to be the main reason.
Any help???

PS NO LAUGHING....I HATE TO BE LAUGHED AT just joking
Thanks
-dfezz1


My /etc/inittab:
For Ref.
########################################

[root@myserver Project_Server_Files]# cat /etc/inittab
#
# inittab This file describes how the INIT process should set up
# the system in a certain run-level.
#
# Author: Miquel van Smoorenburg, <miquels@drinkel.nl.mugnet.org>
# Modified for RHS Linux by Marc Ewing and Donnie Barnes
#

# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)
#
id:3:initdefault:

# System initialization.
si::sysinit:/etc/rc.d/rc.sysinit

l0:0:wait:/etc/rc.d/rc 0
l1:1:wait:/etc/rc.d/rc 1
l2:2:wait:/etc/rc.d/rc 2
l3:3:wait:/etc/rc.d/rc 3
l4:4:wait:/etc/rc.d/rc 4
l5:5:wait:/etc/rc.d/rc 5
l6:6:wait:/etc/rc.d/rc 6

# Trap CTRL-ALT-DELETE
ca::ctrlaltdel:/sbin/shutdown -t3 -r now

# When our UPS tells us power has failed, assume we have a few minutes
# of power left. Schedule a shutdown for 2 minutes from now.
# This does, of course, assume you have powerd installed and your
# UPS connected and working correctly.
pf: powerfail:/sbin/shutdown -f -h +2 "Power Failure; System Shutting Down"

# If power was restored before the shutdown kicked in, cancel it.
pr: 12345owerokwait:/sbin/shutdown -c "Power Restored; Shutdown Cancelled"


# Run gettys in standard runlevels
1:2345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6

# Run xdm in runlevel 5
x:5:respawn:/etc/X11/prefdm -nodaemon
################################################## ######################

[secondmouse]

try this:

sed 's#ca::ctrlaltdel:/sbin/shutdown -t3 -r now#ca:12345:ctrlaltdel:/bin/echo "CTRL-ALT-DEL is disabled"#g' /tmp/dummy

when the above is tested to work, you can replace the string in inittab like this:

sed -i -e 's#ca::ctrlaltdel:/sbin/shutdown -t3 -r now#ca:12345:ctrlaltdel:/bin/echo "CTRL-ALT-DEL is disabled"#g' /etc/inittab

The reason why your code didn't work is that there are "/" within the string to be replaced, which is also the delimiter you use in your sed command. But you don't have to always use "/" to indicate the boundaries, in this case I use "#" (there are a whole lot of characters you can use as the delimiter, as long as they are consistent in the same sed command).

[scm]

I usually use either ! or | delimiters when my patterns contain /s - looks much less ugly (to me) than those comment characters!