Jim Gibson <jimsgib...@gmail.com> writes:
> On Jun 13, 2013, at 10:51 AM, lee wrote:
>> + When I create files with lines like "filename:size:mtime" or
>> "filename:hash", is there something built in to read a syntax like
>> this into, let's say, an array like "my @fileinfo;" with $fileinfo[0]
>> being the file name, $fileinfo[1] the hash?
>> Such 'key:value:...' combinations is probably something frequently
>> used. I'm finding some examples to this and don't know what would be
>> the best way to do it.
>
>
> The split function is the normal way of parsing lines like 'filename:hash'.
> You have to make sure that your data fields do not contain the ':' character,
> or whatever character you use to delimit your fields.
>
> my @fields = split(':',$line);
>
> For more complicated formats, the Text::CSV module can be used.
>
> You could also use the Storable or Data::Dumper modules to write out a hash
> or array containing your data structure to a file and read it back the next
> time you run your program.
Thank you!
So I started implementing some functions (simple and inefficient), and
for reading size, mtime and has from a file, I came up with this:
[CODE]
[...]
sub dbreadhash {
#
# dbreadhash("hashs.list", "filename"): find the entry for "filename" in the
# hashs.list and return size, mtime and hash
#
my ($filename, $key) = @_;
$key .= ":";
my @ret;
if( -e $filename) {
open(my $file, "<$filename");
while( <$file> ) {
chomp $_;
if( m/^$key/ ) {
@ret = split(':', $'); #'
last;
}
}
close($file);
}
else {
print $filename . " not found\n";
}
if(scalar(@ret) != 3) {
print "no or invalid syntax in " . $filename . "\n";
@ret = ( -1, -1, "");
}
return @ret;
}
# test: try out dbreadhash
my @test = dbreadhash("testfile", "this");
print $test[0] . "\n";
[/CODE]
This is expecting lines like:
/path/filename:123:456:hash
How is the return value of the split() function defined for instances
when splitting is not possible? All the documentation I found uses
examples that can be split, and checking the array size like this is
merely based on assumptions ...
--
"Object-oriented programming languages aren't completely convinced that
you should be allowed to do anything with functions."
http://www.joelonsoftware.com/items/2006/08/01.html
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