hi everybody,
i'm a principiant on linux system so excuse me for my following stupid question...

i have a LOGFILE which i need to view as soon as the events come...moreover i need to apply a filter on the events

now i use:
tail -f LOGFILE | grep PATTERN

the problem is that my LOGFILE has the following feature:
DATE
INFO1
INFO2
INFO3
INFO4
INFO5

but i need "tail" command presents me data in this way:

DATE - INFO1 - INFO3 - INFO5

what's the command line i have to use?

THANKS A LOT!!!

Try this :

Beware that you'll have a delayed output as the pipe processing is buffered.

I tried Agrouf suggestion:

tail -f LOGFILE | grep PATTERN | while read line
do
printf "$line - "
done

but i received this warning:
line 3: printf: --: invalid option
printf: usage: printf format [arguments]

moreover....do you know how can i print only some lines? for example first, second and fifth?

THANKS A LOT!!

i tried this way:

tail -f LOGFILE|grep PATTERN|while {read line} {
printf \n
set lineCount 0
if {lineCount==0||lineCount==3||lineCount==4} then {printf "$line "}
incr lineCount
}

but i receive this error:

line 6: syntax error near unexpected token `}'
line 6: `}'


PLEASE, WHERE IS THE ERROR?!?!?

thanks

The error is in the use of curly braces {} to enclose the list of commands.

Change this:
tail -f LOGFILE|grep PATTERN|while {read line} {
printf \n
set lineCount 0
if {lineCount==0||lineCount==3||lineCount==4} then {printf "$line "}
incr lineCount
}

to this:
tail -f LOGFILE|grep PATTERN|while {read line}
do
printf \n
set lineCount 0
if {lineCount==0||lineCount==3||lineCount==4} then {printf "$line "}
incr lineCount
done

no way, this is the error:


line 7: syntax error near unexpected token `done'
line 7: `done'

Are you using bash?
Anyway, try this :
awk syntax is the same, no matter the shell.

I don't understand about the logfile feature you are talking about.
Could you post a portion of the logfile. Piping through grep or sed should filter out unwanted lines.

If there is a blank line between INFO5 and the next date, you can use "awk" and change the record separater to a blank line. However, you won't see output until the end of the record.

BTW you forgot fi after if.

That should be :

tail -f LOGFILE|grep PATTERN|while read line
do
echo
# set lineCount 0 ==> is it tcsh?
lineCount=0 # bash style
if [ $lineCount=0 -o $lineCount=3 -o $lineCount=4 ]
then
printf "%s " $line # may work with your printf?
fi
lineCount=$(expr $lineCount + 1)
done

I believe you are confusing C and bash... ?

sorry,
but i don't know what's my shell

how can i check it?

thanks

PS: i told you i'm a beginner...

What is the output of :
grep $USER /etc/passwd | cut -d ":" -f 7

this is the output:

/bin/bash
/sbin/nologin


i tried last "Agrouf" suggestion but i received this kind of otuput:

+ printf '%s ' Date: 6/26/07 1:23:49 PM
Date: 6/26/07 1:23:49 PM ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' Logname: NAME12
Logname: pippo ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' Logtype: TYPE12
Logtype: TYPE ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' LogUser: USER12
LogUser: USER ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' LogClient: CLIENT12
LogClient: CLIENT ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' LogServer: SERVER12
LogServer: SERVER ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' LogLife: LIFE12
LogLife: LIFE ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' LogContent: CONTENT12
LogContent: CONTENT ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'
+ printf '%s ' --
-- ++ expr 0 + 1
+ lineCount=1
+ read line
+ lineCount=0
+ '[' 0=0 -o 0=3 -o 0=4 ']'


i inserted an "echo off" command at the begin of the script but anything is changed...


For "jschiwal": this is what my tail|grep returns to me; i need only lines 1, 3, 4

...
Date: 6/26/07 1:33:14 PM
LogName: NAME1
Logtype: TYPE1
LogUser: USER1
LogClient: CLIENT1
LogServer: SERVER1
LogLife: LIFE1
LogContent: CONTENT1
--
Date: 6/26/07 1:33:15 PM
LogName: NAME2
Logtype: TYPE2
LogUser: USER2
LogClient: CLIENT2
LogServer: SERVER2
LogLife: LIFE2
LogContent: CONTENT2
--
Date: 6/26/07 1:33:16 PM
LogName: NAME3
Logtype: TYPE3
LogUser: USER3
LogClient: CLIENT3
LogServer: SERVER3
LogLife: LIFE3
LogContent: CONTENT3
...

to complete infos:

i need a logfile like this:

...
Date: 6/26/07 1:33:14 PM - Logtype: TYPE1 - LogUser: USER1
Date: 6/26/07 1:33:15 PM - Logtype: TYPE2 - LogUser: USER2
Date: 6/26/07 1:33:16 PM - Logtype: TYPE3 - LogUser: USER3
...

what is the output of
echo off is a dos command.
try
and