Hi,
I have text file like the following:

Start
a
b
121
c
d
End
Start
a
31
e
f
End
Start
p
o
i
k
l
993
End

 
awk -v V="121" ' /Start/ {
        s=x;
        s=$0;
} !/Start/&&!/End/ {
        s=s RS $0;
} $0 == V {
        f = 1;
} /End/ && f == 1 {
        s=s RS $0;
        print s;
        f = 0;
}' file

Got the solution

awk '/Start/{s=x}{s=s$0"\n"}/121/{p=1}/End/ && p{print s;exit}' <filename>

Converting it each section to rows, simplify handling it.

awk '{if ($0~"End") {print $0"\n"} else {print $0","}}' ORS="" | awk '/k/'
Start,p,o,i,k,l,993,End

Note that this program will not print another section if the search pattern is repeated. But if that is what you want, then it is OK.

Hi bipinajith, the search string will not appear in multiple blocks, thanks for thinking about this.

After I posted my question I found solution based on the following link (credit goes to this):
http://www.unix.com/shell-programmin...o-strings.html