Shell Programming and Scripting

I have a shell script that used to look for a particular sting in the last line of a log file. Howeve this string now has moved to the 3rd or 4th line from bottom.

Can anyone point me to how i easiest chage this one to look within the last frew lines (5 or so) for the particular string rather than just the very last one.

Here's the code that's used:

Code:

while [ "${SUCCESS}" = "FAILED" ]
do
LOGINFO="`/usr/bin/cat "${LOGFILE_NBU}" | /usr/bin/nawk \
'BEGIN{
last_line="";
}
{ # Main
if ($0 != ""){
last_line=$0;
}
} # end of Main
END{
printf("%s",last_line);
}'`"

if [ "${LOGINFO}" != "" ]
then

SUCCESS="`echo "$LOGINFO" | /usr/bin/nawk \
'BEGIN{
tsys_success="";
success="";
fla_backup=0;
fla_success=0;
number=0;
m=0;
}
{ # main
number=(split($0,arr00,""));
for (m=1; m <= number; m++){
if (index(arr00[m],"User_")>0){
fla_backup=1;
}

if (index(arr00[m],"essfull")>0){
fla_success=1;
}
if ((fla_backup==1) && (fla_success==1)){

success="OK";
printf("%s",success);
}
else{
success="FAILED";
printf("%s",success);
}
} # for loop
}'`" # end of main
fi

if [ ${i} -lt $LEFT_TIME ]
then
echo "+ + + + INFO :`/usr/bin/date`: Left time(secs) = $LEFT_TIME, WAITED_TIME(secs)=$i !"
echo "+ + + + INFO :`/usr/bin/date`: We are still waiting for the right information in the NBULOGFILE before we could proceed!"
/usr/bin/sleep 60
i=`expr $i + 60`
else
break
fi

done

Thanks for helping me.

Moderator's Comments:

Please use code tags when posting data and code samples!

Look at the command 'tail':

Code:

tail -n20 $logFile

will print last 20 lines of $logFile.

Thanks for the quick reply.

tail -n would be fine, but when you look at the code there are some clauses to it.

How would I implement it within this code sniplet?

Code:

tail -5 log_file.txt|while read line
do
    echo $line | # your nawk goes here and 
done

Or you could store the last few lines in temp file and run nawk on it

Hi kumaran_5555,

if i understand you correctly here, you would be replacing the whole of:

while [ "${SUCCESS}" = "FAILED" ]
do
LOGINFO="`/usr/bin/cat "${LOGFILE_NBU}" | /usr/bin/nawk \
'BEGIN{
last_line="";
}
{ # Main
if ($0 != ""){
last_line=$0;
}
} # end of Main
END{
printf("%s",last_line);
}'`"

if [ "${LOGINFO}" != "" ]
then


with just:

tail -5 log_file.txt|while read line
do
echo $line | /usr/bin/nawk \
'BEGIN{
tsys_success="";
success="";
fla_backup=0;
fla_success=0;
number=0;
m=0;
}
{ # main
number=(split($0,arr00,""));
for (m=1; m <= number; m++){
if (index(arr00[m],"User_")>0){
fla_backup=1;
}

if (index(arr00[m],"essfull")>0){
fla_success=1;
}
if ((fla_backup==1) && (fla_success==1)){

success="OK";
printf("%s",success);
}
else{
success="FAILED";
printf("%s",success);
}
} # for loop
}'`" # end of main
fi
I am lost here...?
Thanks for giving me a heads up

Please use code tags!

no need for the while loop. Pipe it directly

Code:

tail -n5 logFile | nawk '{...}'

The code I opend the thread with is part of a whole compex scipt that seems do been written by somone dunno how to put this.
And I just try to change the code that is there with minimal invasion as possible to the whole thing as there is other code that would rely on the whole script to still work...and the whole thing has got a wrapper round with the loop that the script will look into the log file for 20hours to see if the string will occur. However as pointed out the string simply doesn't occure in the last line anymore so either the whole log file has to get grepped for or at least the last 5 lines...

Thanks for your great help and input!

---------- Post updated at 07:17 AM ---------- Previous update was at 06:40 AM ----------

I am coming up with the following which now should be doing the same but looking into the last 5 lines of the log file:



LEFT_TIME=`expr $CON_TIME_DIFF - $DIFF_TIME` # the time we would wait for success entry in nbulog!

if [ ${DIFF_TIME} -lt ${CON_TIME_DIFF} ]
then

i=0
SUCCESS="FAILED"

while [ "${SUCCESS}" = "FAILED" ]
do
LOGINFO="`/usr/bin/tail -n5 "${LOGFILE_NBU}" | /usr/bin/nawk \
'BEGIN{
last_line="";
}
{ # Main
if ($0 != ""){
last_line=$0;
}
} # end of Main
END{
printf("%s",last_line);
}'`"

if [ "${LOGINFO}" != "" ]
then

SUCCESS="`echo "$LOGINFO" | /usr/bin/nawk \
'BEGIN{
tsys_success="";
success="";
fla_backup=0;
fla_success=0;
number=0;
m=0;
}
{ # main
number=(split($0,arr00,""));
for (m=1; m <= number; m++){
if (index(arr00[m],"User_")>0){
fla_backup=1;
}

if (index(arr00[m],"essfull")>0){
fla_success=1;
}
if ((fla_backup==1) && (fla_success==1)){

success="OK";
printf("%s",success);
}
else{
success="FAILED";
printf("%s",success);
}
} # for loop
}'`" # end of main
fi