NAME
Text::XLogfile - read and write xlogfiles
VERSION
Version 0.04 released 26 Mar 08
SYNOPSIS
use Text::XLogfile ':all';
my @scores = read_xlogfile("scores.xlogfile");
for (@scores) { $_->{player} = lc $_->{player} }
write_xlogfile(\@scores, "scores.xlogfile.new");
my $xlogline = make_xlogline($scores[0], -1);
my $score = parse_xlogline($xlogline);
print "First place: $score->{player}\n";
print "$xlogline\n";
each_xlogline("scores.xlogfile" => sub {
printf "%s (%d points) %s\n", $_->{player}, $_->{score}, $_->{death};
});
xlogfile format
'xlogfile' is a simple line-based data format. An xlogfile is analogous
to an array of hashes. Each line corresponds to a hash. A sample
xlogline looks like:
name=Eidolos:ascended=1:role=Wiz:race=Elf:gender=Mal:align=Cha
This obviously corresponds to the following hash:
{
ascended => 1,
align => 'Cha',
name => 'Eidolos',
race => 'Elf',
role => 'Wiz',
gender => 'Mal',
}
xlogfile supports no quoting. Keys and values may be any non-colon
characters. The first "=" separates the key from the value (so in
"a=b=c", the key is "a", and the value is "b=c". Colons are usually
transliterated to underscores. Like a Perl hash, if multiple values have
the same key, later values will overwrite earlier values. Here's
something resembling the actual grammar:
xlogfile <- xlogline [\n xlogline]*
xlogline <- field [: field]*
field <- key=value
key <- [^:=\n]*
value <- [^:\n]*
xlogfiles are used in the NetHack and Crawl communities. CSV is too
ill-defined. XML is too heavyweight. I'd say the same for YAML and JSON.
FUNCTIONS
read_xlogfile FILENAME => ARRAY OF HASHREFS
Takes a file and parses it as an xlogfile. If any IO error occurs in
reading the file, an exception is thrown. If any error occurs in parsing
an xlogline, then an empty hash will be returned in its place.
parse_xlogline STRING => HASHREF
Takes a string and attempts to parse it as an xlogline. If a parse error
occurs, "undef" is returned. The only actual parse error is if there is
a field with no "=". Lacking ":" does not invalidate an xlogline; the
entire line is a single field.
Since xlogfiles are an inherently line-based format, the input will be
chomped. Any other newlines in the input will be incuded in the output.
each_xlogline FILENAME, CODE
This runs the code reference for each xlogline in the given file. The
xlogline will be passed in as a hashref and as $_. If any IO error
occurs in reading the file, an exception is thrown. If any error occurs
in parsing an xlogline, then an empty hash will be used in its place.
write_xlogfile ARRAYREF OF HASHREFS, FILENAME
Writes an xlogfile to FILENAME. If any IO error occurs, it will throw an
exception. If any error in making the xlogline occurs (see the
documentation of "make_xlogline"), it will automatically be corrected.
Returns no useful value.
make_xlogline HASHREF[, INTEGER] => STRING
Takes a hashref and turns it into an xlogline. The optional integer
controls what the function will do when it faces one of three potential
errors. A value of one will correct the error. A value of zero will
cause an exception (this is the default). A value of negative one will
ignore the error which is very likely to cause problems when you read
the xlogfile back in (you may want this when know for sure that your
hashref is fine).
The potential problems it will fix are:
Keys with "="
If a key contains "=", then it will not be read back in correctly.
Consider the following field:
foo=bar=baz
The interpretation of this will always be 'foo' = 'bar=baz'.
Therefore a key with "=" is erroneous. If error correcting is
enabled, any "=" in a key will be turned into an underscore, "_".
Keys or values with ":"
Because colons separate fields and there's no way to escape colons,
any colons in a key or value is an error. If error correcting is
enabled, any ":" in a key or value will be turned into an
underscore, "_".
Keys or values with "\n"
xlogfiles are a line-based format, so neither keys nor values may
contain newlines, "\n". If error correcting is enabled, any "\n" in
a key or value will be turned into a single space character.
AUTHOR
Shawn M Moore, "<sartak at gmail.com>"
BUGS
No known bugs.
Please report any bugs through RT: email "bug-text-xlogfile at
rt.cpan.org", or browse to
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Text-XLogfile>.
ACKNOWLEDGEMENTS
Thanks to Aardvark Joe for coming up with the xlogfile format. It's much
better than NetHack's default logfile.
COPYRIGHT & LICENSE
Copyright 2007-2008 Shawn M Moore.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.