help with regex

[George Mpouras]

I must discover all possible field names of a key/value file.
The properties of the file are unknown so I must be a little creative.
The values optional can have whitespaces inside "..."
its key/value separated with a space from the next pair.
Do you thing the following is ok ?



#!/usr/bin/perl
use strict;
use warnings;

while(<DATA>) { chomp;

while ( /([^=]+)=("[^"]+"|\S+)/g ) {
my ($key, $val) = ($1, $2);
$val =~s/^["\s]*(.*?)["\s]*$/$1/;
print "*$key* *$val*\n"
}

print "--------\n"
}


__DATA__
f1=hello f2= f3="foo" f4="hello world"
f6="day" f7="day & night" f8=100

[Tim McDaniel]

In article <kps6f4$15u3$1...@news.ntua.gr>,

George Mpouras <nospam.gravital...@hotmail.noads.com> wrote:
>I must discover all possible field names of a key/value file.
>The properties of the file are unknown

If by "properties" you mean the layout, format, et cetera,
then how can anyone advise you on a proper way to parse it
when neither you nor we know what's valid?

--
Tim McDaniel, tm...@panix.com

[Peter Gordon]

George Mpouras <nospam.gravital...@hotmail.noads.com> wrote
in news:kps6f4$15u3$1...@news.ntua.gr:

You don't say if all possible sequences are included in the data.
If they are, the code below decodes it.

#!/usr/bin/perl -w
use strict;
use 5.14.0;
my %lines;
while( <DATA> ) {
chomp;
last if /^$/; # Catch blank lines at end of data.
while ( /(f\d+)=(.*?)(?: f\d+=|$)/ ) {
my $key = $1;
my $value = $2;
s/$key=$value(.*)/$1/; # Strip the key/value pair off the
string.
$value =~ s/"(.*)"/$1/; # Strip off any "
$lines{$key} = $value;
}
}
say "The Hash";
foreach my $key (sort keys %lines ) {
say "$key: $lines{$key}";

[Martijn Lievaart]

On Thu, 20 Jun 2013 09:52:11 +0000, Peter Gordon wrote:

> You don't say if all possible sequences are included in the data.
> If they are, the code below decodes it.
>
> #!/usr/bin/perl -w use strict;
> use 5.14.0;
> my %lines;
> while( <DATA> ) {
> chomp;
> last if /^$/; # Catch blank lines at end of data.
> while ( /(f\d+)=(.*?)(?: f\d+=|$)/ ) {
> my $key = $1;
> my $value = $2;
> s/$key=$value(.*)/$1/; # Strip the key/value pair off the
> string.
> $value =~ s/"(.*)"/$1/; # Strip off any "
> $lines{$key} = $value;
> }
> }
> say "The Hash";
> foreach my $key (sort keys %lines ) {
> say "$key: $lines{$key}";
> }
> __DATA__
> f1=hello f2= f3="foo" f4="hello world"
> f6="day" f7="day & night" f8=100

I'ld do:

#!/usr/bin/perl -w
use strict;
use 5.14.0;
my %lines;
while( <DATA> ) {
chomp;

next if /^$/; # Skip blank lines
while (s/ \s* (f\d+) = (?: (".*?" | \w* ) \s* ) //x ) {
$lines{$1} = $2
}
die "'$1'" if /(..*)/;

}
say "The Hash";
foreach my $key (sort keys %lines ) {
say "$key: $lines{$key}";
}
__DATA__
f1=hello f2= f3="foo" f4="hello world"
f6="day" f7="day & night" f8=100

What it doesn't do is f99="\"" or a lot of other useful stuff. Anyone
know a module for this?

M4

[George Mpouras]

key names can be whatever string with no spaces not f\d+
f100 etc was an example, so the regex

/(f\d+)=(.*?)(?: f\d+=|$)/ )

is not catching correctly

[George Mpouras]

key names can be whatever string with no spaces not only f\d+

[George Mpouras]

you are correct, specs are loosy
lines with multiple key/value pairs separated by space
keys are not containing space
values may contain space inside double quotes

[Tim McDaniel]

In article <kpvome$ck5$1...@news.ntua.gr>,

George Mpouras <nospam.gravit...@spamno.hotmail.anispam.com.nospam> wrote:
>key names can be whatever string with no spaces not f\d+

The examples were the only spec you gave, so you can understand why
people coded to it.

>f100 etc was an example

An example provided by the teacher of the class?

Settings separated by space: do you mean one space or one or more
characters of whitespace?
Is there always an "="? That is, you can't have "foo bar"; it must be
"foo= bar="?
Can there be whitespace around "=", as in "foo = bar";
Can there be leading whitespace and/or trailing whitespace on the line?

--
Tim McDaniel, tm...@panix.com

[Martijn Lievaart]

On Thu, 20 Jun 2013 16:33:35 +0200, Martijn Lievaart wrote:

> while (s/ \s* (f\d+) = (?: (".*?" | \w* ) \s* ) //x ) {

Hummm...

while (s/ \s* (f\d+) = (".*?" | \w* ) \s* //x ) {

Does the job just as well. Dunno what I was smoking.

M4

[Martijn Lievaart]

On Thu, 20 Jun 2013 23:30:00 +0300, George Mpouras wrote:

> key names can be whatever string with no spaces not only f\d+

Replace f\d+ with \w+ or [^ ]+

M4

[George Mpouras]

> An example provided by the teacher of the class?

!!!!!!!!!!!!!!!!!!!!!!!!!!