Process between paragraphs in perl

[Ninja Li]

Hi,

I have a file with the following format, with common words "Sort
Alphabetically" for each paragraph:

London|Sort Alphabetically
line1
line2
line3
Chicago|Sort Alphabetically
line1
line2
Shanghai|Sort Alphabetically
line1
line2

I would like to print the country name after each line under city,
so the output will be something like:
London|Sort Alphabetically
line1 | UK
line2 | UK
line3 | UK
Chicago|Sort Alphabetically
line1 | US
line2 | US
Shanghai|Sort Alphabetically
line1 | China
line2 | China

I tried to split each paragraph into separate file base on "Sort
Alphabetically" and then merge them again. This is quite tideous. Is
there an easier way to do this without splitting into separate files?
The following is some of my code:

open(INFILE, "<$file");

foreach $line (<INFILE>)
{
if ($line =~ /Alphabetically/)
{
my @fields = split(/\|/, $line);
$location = $fields[0];

if ($location =~ /London/)
{
$location = 'UK';
}
elsif ($location =~ /Chicago/)
{
$location = 'US';
}
elsif ($location =~ /Shanghai/)
{
$location = 'China';
}
elsif ($location =~ /.../)
{
$location = '..';
}

close(OUTFILE);
open(OUTFILE, ">$output$location");
}
print OUTFILE $line;
}

 

[Ninja Li]

This is a nice solution. Thanks for your help.