You forgot to mention what's not working

In your case it is a missing line

__DATA__
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right before the example data, and a regex you might change to

s/<([^>]*)>/\{$1\}\n/g;
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or alternatively

s/<(.*?)>/\{$1\}\n/g;
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Note that this is probably still short of what you want, since you seem to need to throw away ending tags. In that case you could add '/' to the character class above and throw away the ending tags in a second regex

I think this is a better regex to solve this problem:

s!\s*<\s*(/?)\s*(\w+)\s*>\s*!$1?"\n":"\n\{$2\}\n"!ge;
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because </ttl> should not appear (from the example's output) and there is a problem with extra white spaces surrounding and inside tags. Also, there was no info on what to do if there is more text after a closing tag, so I guessed that a new line must be inserted.

But that regex will generate extra empty lines if a data line starts with a tag. Changing to this should do the trick:

s!\s*<\s*(/?)\s*(\w+)\s*>\s*!$1?"\n":"\n\{$2\}\n"!ge and s!^\n!!;
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Please note that I kept the \w+ for the capture, asuming that only alphanumerics are admited as tags.

What if you have <> inside your tags? Text::Delimited can solve a lot of your problems for this kind of parsing. More info here.

#! usr/bin/perl

use strict;
use warnings;
use Text::Balanced qw/extract_bracketed/;

while( <DATA> ) {
  my $in = $_;
  print "\nIN : $in"; ## input
  my $out = $in;
  ## OK if you never have \<\> inside \<\>
  $out =~ s/\<([^\>]+)\>/\n\{$1\}\n/g;
  print "\tOUT 1 : $out"; ## simple output

  ## Have to be more clever if it does
  ## extract balanced delimiters
  my @extracted = extract_bracketed($in, '<>');
  if (!defined$extracted[0]){
    ## undefined if no balanced delimiters existed
    ## so print straight out
    print "\tOUT 2 : $in";
  }
  else {
    ## balanced delimters were found, 
    ## so process them as before
    print "\tOUT 2 : ";
    for (@extracted){
      s/^\<(.+)\>$/\n\{$1\}\n/g;
      print $_;
    }
  }
}


__DATA__
[SOUR]
Por Gisela Orozco 312.527.8461/ Chicago\
<line> Por Gisela Orozco< ttl>312.527.8461/ Chicago</ttl>
<<test>>extra bumphf
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Will produce the right output more robustly (see the last input line) :

HTH

Moving away from say <ttl>blah..blah</ttl> to a less standard format of {ttl}blah..blah, is in my opinion a mistake.

There are lots of modules that can deal with: <ttl>blah..blah</ttl>. So I opted below to do what I could to "clean things up". I don't think that what you are asking for is a good idea. Of course there could be things that I don't know.

#!/usr/bin/perl -w
use strict;

while( <DATA> ) 
{
   s/<\s*/</g;     #compress spaces right after "< xxx"
   s/\s*>/>/g;     #compress spaces right before "xxx >"
   s/(.)</$1\n</g; #add \n before < if not already on new line
   print $_;
}

# prints:
# [SOUR]
# Por Gisela Orozco 312.527.8461/ Chicago\
# <line> Por Gisela Orozco
# <ttl>312.527.8461/ Chicago
# </ttl>

__DATA__
[SOUR]
Por Gisela Orozco 312.527.8461/ Chicago\
<line> Por Gisela Orozco< ttl>312.527.8461/ Chicago</ttl  >
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#!/usr/bin/perl
use strict;
use warnings;

my $tag;
my $output;
my $fh;
my $deletestrings;

while (<DATA>) {
s/\s*<\s*(\/?)\s*(\w+)\s*>\s*/$1?"\n":"\n\{$2\}\n"/ge;
    chomp;
 s/[\cA-\cZ]//g;     # To remove control characters
        s/^[\\|<]$//g; # To delete the character like \ and < at the e
+nd of the line
        s/[\\|<]$//; # To delete the character like \ and < at the beg
+ining of the line
        s/^\s+//g;  # To remove multiple spaces at the begining of the
+ line
        s/\s+$//g; # To remove  spaces at the end  of the line
    if(/^{(.*)}$/) {    # match {METATAG} line
        $fh = output($output, $tag, $fh);
        $output = "";
        $tag = $1;
    } else {            # not a {TAG} line
        next unless($tag);
        next if(/^\s*$/);
        s/\\//g;
        $output .= ($output) ? " $_" : "<$tag>$_";
    }
}

$fh = output($output, $tag, $fh);
if($fh) {
    print $fh "</ROOT>\n";
    close($fh);
}
exit(0);

# Subroutine to open the file with the filename as {SOURCETAG}
# Subroutine to open the file with the filename as {SOURCETAG}
sub output {
    my ($output, $tag, $fh) = @_;
    if($output) {
        if($output =~ m/<SOURCE>(.*)/) {
            if($fh) {
                print $fh "</ROOT>\n";
                close($fh);
            }
            open($fh, '>', "$1.xml") or die "$1.xml: $!";
            print $fh "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<RO
+OT>\n";
        }
        print $fh "$output</$tag>\n";
    }
    return($fh);
}
__DATA__
{SOURCE}
0904230634
{DATE}
090424
{EDITION}
1
{HEADLINE}
heredero del famoso deportista mexicano, lucha por enaltecer la vida y
+ obra
del autor de sus dM-mas
{SOURCE1}
Por Gisela Orozco 312.527.8461/ Chicago\
<byline> Por Gisela Orozco< ttl>312.527.8461/ Chicago</ttl>
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When executed, it creates a file called 0904230634.xml in the current directory. The output is

<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
<SOURCE>0904230634</SOURCE>
<DATE>090424</DATE>
<EDITION>1</EDITION>
<HEADLINE>heredero del famoso deportista mexicano, lucha por enaltecer
+ la vida y obra del autor de sus dM-mas</HEADLINE>
<SOURCE1>Por Gisela Orozco 312.527.8461/ Chicago {byline}Por Gisela Or
+ozco{ttl}312.527.8461/ Chicago</SOURCE1>
</ROOT>
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So Instead of

<?xml version="1.0" encoding="UTF-8"?>
<ROOT>
<SOURCE>0904230634</SOURCE>
<DATE>090424</DATE>
<EDITION>1</EDITION>
<HEADLINE>heredero del famoso deportista mexicano, lucha por enaltecer
+ la vida y obra del autor de sus dM-mas</HEADLINE>
<SOURCE1>Por Gisela Orozco 312.527.8461/ Chicago</SOURCE1>
<byline>Por Gisela Orozco</byline>
<ttl>312.527.8461/ Chicago</ttl>
</ROOT>
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So please tell me why the string is replaced only with {} and further it is not converted to < as for other tags

Please tell the name of this format. What is the name of this format?

open(DATA,"sample.txt") or die $!;
while( $line=<DATA> ) {
$line=~s/<(\w+)>/\{$1\}\n/g;
$line=~s/<\s(\w+)>/\n\{$1\}\n/g;
$line=~s/<\/\w+>//g;
print $line;
}
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