Perl: Keeping Leading Zeros

[Hase]

There might be better places to ask but I already have an account here and like this ravenous crowd.

So, I have a script that uses an incrementing variable within a filename. That filename is generated using a leading zero for the digits "01" through "09." When I increment in the script, it drops the leading zero off rendering the script unable to locate the file.


for ($day = 01; $day < 31; $day++) {
system ("ssh remote_machine \"cat /log/reports/$year/$month/$day/summary_$year-$month-$day.txt | grep -v 'whatever'\" >> $temp_file 2>/dev/null");


Thanks!?

[pmasiar]

http://perldoc.perl.org/functions/sprintf.html - on first page when you http://www.google.com/search?q=perl+number+formatting

[Hase]

for ($day = "01"; "$day" < 31; $day++) {
system ("ssh remote_machine \"cat /log/reports/$year/$month/$day/summary_$year-$month-$day.txt | grep -v 'whatever'\" >> $temp_file 2>/dev/null");

[Hase]

http://perldoc.perl.org/functions/sprintf.html - on first page when you http://www.google.com/search?q=perl+number+formatting

Thanks, I was googling the wrong thing for two hours.

I think that the solution I stumbled across is much more straight forward though, since I'm not trying to "re"-format, just keep formatting.

[pmasiar]

I know how it hurts: You know **exactly** that answer is trivial, but for hour cannot whip up decent keywords for Google... :-( Doing it all the time, always learn something new unexpectedly... :-)

[bashologist]

Those lines are very long, you could maybe split them up a bit like this.

for ($day = 1; $day < 31; $day++)
{
$file = sprintf "/log/reports/$year/$month/%02d/summary_$year-$month-$day.txt", $day;
system ("ssh remote_machine \"cat '$file' | grep -v 'whatever'\" >> $temp_file 2>/dev/null");
}

[Hase]

I'll play around with that on Monday. Thanks all!