Shell Programming and Scripting

$ cat c.sh
#! /bin/sh

if [ $# -ne 2 ]; then
        echo "Usage: $0 <input> <pattern>"
        exit 1
fi


awk '
$1 ~ /^'$2'$/ {
        for (i=1;i<=11;++i) {
                n=getline
                if (n==0) {
                        exit
                }
        }
        print
        exit
}' $1

$ cat c.in
Line1 a line
Line2 a line
Line3 a line
Line4 a line
Line5 a line
Line6 a line
Line7 a line
Line8 a line
Line9 a line
Line10 a line
Line11 a line
Line12 a line
Line13 a line
Line14 a line
Line15 a line

$ ./c.sh c.in Line1
Line12 a line

$ ./c.sh c.in Line4
Line15 a line

$ ./c.sh c.in Line5

$

awk '{_[NR%2]=$2;l[NR%2]=$NF}$NF==0 && l[(NR+1)%1]!=0 {print _[(NR+1)%1]-$2}' file

#!/bin/sh
x=0 && y=0;
while read a b c
do
  if test \( $c -gt 0 \) ; then
    x=1 && y="$b";
  elif test \( $c -eq 0 \) -a \( $x -eq 1 \)  -a \( ! -z $y \); then
    echo "$y - $b" | bc && x=0 && y=0;
  fi
done < file