Grep moving spaces? - shell

Question

{
while read -r line ; do
if grep -q '2015' $line
then
echo "inside then"
echo "$line"
echo "yes"
fi
done
} < testinput
Once I execute the above code the output is:
inside then
( nothing is printed in this line its spaces)
yes
Why is that input line is not getting printed in the second output line?
Your help is appreciated. The reason why I am asking is that I actually have to perform a few operations on the input line after the match using grep is successful.
Input file Sample :
2015-07-18-00.07.28.991321-240 I84033A497 LEVEL: Info
PID : 21233902 TID : 9510 PROC : db2sysc 0
INSTANCE: xxxxxxxx NODE : 000 DB : XXXXXXX
APPHDL : 0-8 APPID: *LOCAL.xxxxxxx.150718040727
AUTHID : XXXXXXXX
EDUID : 9510 EDUNAME: db2agent (XXXXXXXX) 0
FUNCTION: DB2 Common, SQLHA APIs for DB2 HA Infrastructure
I need to capture the time when SQLHA shows up in the input file or log file. To do that first I find the match for time in the input file and then I save that time in the variables. Once I find SQLHA I will write the time saved in the variables into an output file. So for every occurrence of SQLHA in the log, I will write the time to the output file.

Answer 1

After the update about what is really wanted, it is fairly clear that
you should probably use awk, though sed would also be an option (but harder). You can do it in shell too, though that's messier.
awk '/^2015-/ { datetime = $1 } / SQLHA / { print datetime }' testinput
Using sed:
sed -n -e '/^2015-/ {s/ .*//; h; n; }' -e '/ SQLHA / { x; p; x; }' testinput
(If you find 2015- at the start of a line, remove the stuff after a space and save it in the hold space. If you find SQLHA with spaces on either side, swap the hold and pattern space (thus placing the saved date/time in the pattern space), then print it, then switch it back. The switch back means that if two lines contain SQLHA between occurrences of the date line, you'll get the same date printed twice, rather than a date and then the first of the SQLHA lines. You end up having to think about what can go wrong, as well as what to do when everything goes right — but that may be more for later than right now.)
Using just sh:
while read -r line
do
case "$line" in
(2015-*) datetime=$(set -- $line; echo $1);; # Absence of quotes is deliberate
(*SQLHA*) echo "$datetime";;
esac
done < testinput
There are many other ways to do that in shell. Some of them are safer than this. It'll work on the data shown safely, but you might get to run against maliciously created data.
while read -r line
do
case "$line" in
(2015-*) datetime=$(echo "$line" | sed 's/ .*//');;
(*SQLHA*) echo "$datetime";;
esac
done < testinput
This invokes sed once per date line. Using Bash, I guess you can use:
while read -r line
do
case "$line" in
(2015-*) datetime="${line/ */}";; # Replace blank and everything after with nothing
(*SQLHA*) echo "$datetime";;
esac
done < testinput
This is the least likely to go wrong and avoids executing an external command for each line. You could also avoid case…esac using if and probably [[ so as to get pattern matching. Etc.
Running your script on a Mac, I get error output such as:
grep: 2015-07-18-00.07.28.991321-240: No such file or directory
grep: I84033A497: No such file or directory
grep: LEVEL:: No such file or directory
Are you not seeing that? If you're not, then either you've sent errors to /dev/null (or some other location than the terminal) or you've not shown us exactly the code you're using — or there's a blank line at the top of your testinput file.

Answer 2

This will do what your script is trying to do:
#!/usr/bin/awk -f
/2015/ {
print "inside then"
print
print "yes"
}

Answer 3

This is what I have written(very basic).I will try to run the same program with Grep and post why i am getting the blank space soon.
while read -r line
do
if [[ $line == *2015* ]];
then
dtime=`echo $line | cut -c1-26`
fi
if [[ $line == *SQLHA* ]];
then
echo $dtime
fi
done
} < testinput
Input Used:
2015-07-18-00.07.28.991321-240 I84033A497 LEVEL: Info
EDUID : 9510 EDUNAME: db2agent (SIEB_RPT) 0
FUNCTION: DB2 Common,APIs for DB2 HA Infrastructure, sqlhaAmIin
2015-07-18-00.07.29.991321-240 I84033A497 LEVEL: Info
FUNCTION: DB2 Common, SQLHA APIs for DB2 HA Infrastructure, sqlha
2015-07-18-00.07.48.991321-240 I84033A497 LEVEL: Info
EDUID : 9510 EDUNAME: db2agent (SIEB_RPT) 0
FUNCTION: DB2 Common, SQLHA APIs for DB2 HA Infrastructure, sqlha
O/p :
2015-07-18-00.07.29.991321
2015-07-18-00.07.48.991321