Can someone help with the basics of creating a command that will read a .log file and strip the output to another file that just conatins certain aspects of that original eg:

Scriptlog: ........

basically the log contains loads of data, but i just want a file that shows anything begining with Scriptlog:

i know that to ouput to the file i can do
date $var >> scriptlog.log

or something similar. im extremely new to programing and have a small knowledge of C ( but only windows console applications)

oh and btw i have made something similar in C running as a console application. but how do i do this as a shell script, and i read another thread about make, which updates when the file is edited by something else (eg in my case the server adding to the log.)

Well how abt this
I am using awk to do this . Let me explain

1. I am using : as the field seperator . So, the fields will be stored in $1 $2 so on
2. Then I check if field 1 is equal to "Scriptlog" or not
3. If it is Scriptlog then I just print $0 [ $0 contains the entire line ]
4.This thing I write to another file strip.log

wat exactly does the cat bit do? and does this scan the entire log? and can i make it do this when the log is modified?

Just logged in to my server with ssh, and done help commands, so eg:
cat -A /home/server.log | (then your awk code etc)

It scans the file line by line and so by using a broken pipe | we can put the code into operation

i.e, cat some_file | blahblahblah

where blahblahblah is what you want to do with the file
<edit>
Did my code give u successful results . Was that what you wanted ??
</edit>

Ok, im going to specify further. this is a game server's log, and obviously every time a play joins or it changes map its going to write to the log, is there a way of making the code continue from where it left off and make it so the script is always reading the log file to add the lines?

Use crontab I suppose that would help
or
Put the code you want to run in a while(1) loop and then run this code

Or easier:
Or with sed:
Or with perl:
Or with grep:
Pick any tool you want.

O_o oh ek you know how to confuse a n00b

If it is using crontab then do it this way
type "crontab -e" on the konsole

Then a file will be opened and then in that file
* * * * * fields are as follows minute ,hour,day of month ,month ,day of week

* means it'll be run always . So for every minute your file will be updated
Check out man 5 crontab for more details

Well i used:
awk '/^MMCv110:/ {print}' RGserver.log > strip.log
and that worked this is wot it outputted:
MMCv110: ##########################################
MMCv110: # ModMenuChecker v1.10 by TA`Tremor (PD) #
MMCv110: ##########################################
MMCv110: [MMC] -rG.Hardw1re- :
MMCv110: [MMC] -rG.Hardw1re- : AdvancedInstaGib.AIG_ModMenuItem
MMCv110: [MMC] -rG.Hardw1re- : ChaosUT.ChaosUTModMenuItem
MMCv110: [MMC] -rG.Hardw1re- : ChatLog.ChatLogModMenuItem
MMCv110: [MMC] -rG.Hardw1re- : IRC_Reporter.IRC_Reporter
MMCv110: [MMC] -rG.Hardw1re- : JoltDemoEnhancer2.DEMenuItem
MMCv110: [MMC] -rG.Hardw1re- : MultiMesh.MultiMeshMenu
MMCv110: [MMC] -rG.Hardw1re- : udemo.UDmodItem
MMCv110: [MMC] -rG.Hardw1re- : Weaponer.WeaponerModMenuItem

So if i do a .sh file with this in a while(1){ } loop and make the auto restart script for the server that i use to boot the server run the .sh file this will make it write to the file all the time right??

Thank You so much Satan, i appreciate the help you have given me.

Hardw1re.

hopefully my final post, will this .sh file work:

#!/bin/sh
while(1){ awk '/^MMCv110:/ {print}' /home/utpub2/ut-server/System/RGserver.log > /home/utpub2/strip.log }
while(1){ awk '/^UTPure:/ {print}' /home/utpub2/ut-server/System/RGserver.log > /home/utpub2/strip.log }
done

For persistent following of the log, you can replace the cat (in my examples there were no cat, but it can be put in the beginning of the line with scriptlog.log word removed from the middle.) with a 'tail -f' command. for example:
Drawback: only new data in being written to the log.

Also if you want to do the check only once and a while, you could use the
logtail tool. Syntaxically just replacing the cat or tail -f with logtail.