Input file:

Thu Mar 19 2:34:14 EDT 2009
STC
Data query:

Record 1 of 1

DN: Data Name
Information Sciences
TI: Title
Distribution and abundance of bound volumes of the file in institute
shelves from 1978
AU: Author
Sahu, SR; Gawas, AKG
AF: Affiliation
Inst. of document scanning and documentation profiling at library,
toward the prograssive society and establishment
SO: Source
Test document file. Vol. 5, no. 1, pp. 1-14. Jul 1990.
DE: Descriptors
Article Subject Terms: Abundance; Ecological distribution;
Geographical distribution; Life cycle; Zooplankton; Article Taxonomic
Terms: Euphausia; Article Geographic Terms: ISW,
LA: Language
English

Perl Script:

#!/usr/bin/perl -w

my $found_f = 0;
my ($lastline, $line);
open (INPUTFILE, "test.txt");

while (<INPUTFILE>)
{
chomp;

if (/^[A-Z]{2}:\s/) {
$lastline = $line;
$line = $_;
$found_f = 1;
}
elsif (! /^[A-Z]{2}:\s/ && $found_f) {
s/^ {4}/ /;
$line .= $_;
next;
}
elsif (/^$/) {
$lastline = ' ';
$found_f =0;
}
print "$lastline\n";