generic increment of number/string

[alexxx.magni]

hi everybody,
there is some way to easily loop a padded variable, getting:
0001
0002
0003
0004
....

?

I'd like to do it in a simple for() loop, and I wanted to avoid
checking the total string length...

thanks!


Alessandro Magni

 

[Paul Lalli]

hi everybody,
there is some way to easily loop a padded variable, getting:
0001
0002
0003
0004
...

?

I'd like to do it in a simple for() loop, and I wanted to avoid
checking the total string length...

You've made it more difficult than it is, probably by thinking too much
like a C programmer.

for my $num ('0001' .. '0100') {
print "$num\n";
}

Paul Lalli

 

[alexxx.magni]

thanks!

What I had problem with, was that at first I checked on the command
line,
and there I discovered what still puzzles me:

1) output of your program in a script:
0001
0002
0003
....

2) while instead, perl -e 'for my $num ('0001' .. '0100') {print
"$num\n";}' gives:
1
2
3
....


I really wonder why............


Alessandro

Paul Lalli ha scritto:

 

[Paul Lalli]

What I had problem with, was that at first I checked on the command line,
and there I discovered what still puzzles me:

1) output of your program in a script:
0001
0002
0003
...

2) while instead, perl -e 'for my $num ('0001' .. '0100') {print
"$num\n";}' gives:
1
2
3
...

Did you actually look at the *entire* list, not just the first three?
It only goes up to 64, not 100. That's because you're using single
quotes within the program, and as delimeters to the perl -e.
Therefore, Perl is not seeing single quoted strings. Instead, Perl is
seeing the shell's interpretation of 0001 and 0100, which are octal 1
and octal 64, respectively.

Change the inner single quotes to double quotes, and everything will
work out...

Paul Lalli

 

[alexxx.magni]

that was tricky!

thanks...............


Alessandro

Paul Lalli ha scritto:

 

[Ben Morrow]

Did you actually look at the *entire* list, not just the first three?
It only goes up to 64, not 100. That's because you're using single
quotes within the program, and as delimeters to the perl -e.
Therefore, Perl is not seeing single quoted strings. Instead, Perl is
seeing the shell's interpretation of 0001 and 0100, which are octal 1
and octal 64, respectively.

Minor nit: this has nothing to do with the shell. 0100 is not special to
the shell. The important thing is that perl sees

for my $num (0001 .. 0100) {

instead of

for my $num ('0001' .. '0100') {

, and *perl* interprets 0100 as '100 octal' = 64.

Change the inner single quotes to double quotes, and everything will
work out...

Or escape the quotes, or use q//. That's why it's there, after all.

Ben