I see that you are happy with the flip-flop operator as demo'ed by
haukex. The flip-flop operator in Perl keeps the state of whether or not you are within the beginning or closing statements of some data record. I like that operator, but it may not be the best in all situations.
In a language without the flip-flop operator, another method is to call a subroutine when the beginning of record is seen. Use that subroutine to process the record. This handles the "state information" of whether or not you are inside the record without having to have a flag value. Of course adjustments are necessary depending upon whether the first or last values of the record need to be included or not.
Here is some possible code:
use warnings;
use strict;
while (<DATA>)
{
process_record ($_) if /\@user_info_start/;
}
sub process_record #include first and last line
{
my $start_of_record = shift;
my @userinfo;
push @userinfo, $start_of_record;
my $line;
do {
$line =<DATA>;
push @userinfo, $line;
} until $line =~ /\@user_info_end/;
print @userinfo;
print "\n";
}
=Prints
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
=cut
__DATA__
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
d987sd66bd
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
somebus here or blank lines? whatever
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Or perhaps.
use warnings;
use strict;
while (<DATA>)
{
process_record() if /\@user_info_start/;
}
sub process_record
{
my $line;
print $line while (defined ($line =<DATA>) and $line !~ /\@user_info
+_end/);
print "\n";
}
=Prints
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
=cut
__DATA__
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
d987sd66bd
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
somebus here or blank lines? whatever
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
Update:
of course the first example could avoid a push...In general, Don't "push" when you can "print"!
use warnings;
use strict;
while (<DATA>)
{
process_record ($_) if /\@user_info_start/;
}
sub process_record #include first and last line
{
my $start_of_record = shift;
print $start_of_record;
my $line;
do {
$line =<DATA>;
print $line;
} until $line =~ /\@user_info_end/;
print "\n";
}
=Prints
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
=cut
__DATA__
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
d987sd66bd
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
somebus here or blank lines? whatever
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
I guess yet another way...
use warnings;
use strict;
while (<DATA>)
{
process_record ($_) if /\@user_info_start/;
}
sub process_record # include first and last line
{
my $start_of_record = shift;
print $start_of_record;
my $line;
# a bit of strangeness caused by using <DATA> handle
while (defined ($line=<DATA>) and $line !~ /\@user_info_end/)
{
print $line;
}
print $line; #the last line of record
print "\n";
}
=Prints
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
=cut
__DATA__
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : xxxxx
xxxx*@Filetype : txt
xxxx*@Version : 0001
xxxx*@Create_Date : 20190407
xxxx*@Product : xxxx
xxxx*@user_info_end
d987sd66bd
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxx
xxxx*@user_info_start
xxxx*@Title : Mr
xxxx*@Username : yy
xxxx*@Filetype : txt
xxxx*@Version : 0005
xxxx*@Create_Date : 43
xxxx*@Product : xxxx
xxxx*@user_info_end
somebus here or blank lines? whatever
xxxxxxxxxxxxxxxxxxxxxxxxxxxx
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