I don't know renderman, so i am not sure how complex this is going to grow to, but i think the following will do something similar to what you are asking about : lightly-tested code ahead

#!/usr/bin/perl

my $string;
{
    $/ = undef;
    $string = <DATA>;
}

while ($string =~ m!\[\s*([^]]+)\]!g) {
    my @nums = split(/\s+/,$1);
    print "Array : ",join(',',@nums),"\n";
   
}

__DATA__
[1 1 1 1 1 1 ][4 4 4 4 4 4]

[ 123 123 123
  123 123 123
  123 123 123 ]

"P"

[ -1 1 1
  1 1 -1
  1 1 1 ]
[download]

If renderman has a very complex file format, you may want to write a more robust parser.

Thanks for your fast reply !!!

I use the open ( INPUT, .....)
to read in the file and I want to seprate the 4 array's

so something like this

my @nloops = ...;
my @lverts = ...;
my @vertid  = ...;
my @paramslist = ...;

so your code was nice to print this info but I like to
asign it to 4 array ex.

my @nloops = [ ... ];
my @lverts = [ ... ];
my @vertid = [ ... ];
my @params = [ ... ];

next I could count the array length this I know how to
next I could build a for loop to assign 1 array and first value to new
+ data format ...

ex.

change the data
0.5 0.5 0.5 add 1 -------- first array
to output
0.5 0.5 0.5 1
Print some info here !!!
4 < 1 2 3 4
Print end info !!!

so in another words the 4 arrays need to be seprate.
ex.

print @nloops;
OUT
1,1,1,1,1

print @lverts;
OUT
4,4,4,4,4

...
[download]

I am unsure what you mean about changing the data. While i am not quite clear on that, i do understand you want to save each array of numbers seperatly. To accomplish this, i used an Array of Arrays. The code is listed below (it is untested) :

#!/usr/bin/perl

my $string;
{
    $/ = undef;
    $string = <DATA>;
}

my @collection;
while ($string =~ m!\[\s*([^]]+)\]!g) {
    my @nums = split(/\s+/,$1);
    print "Array : ",join(',',@nums),"\n";
    push(@collection,\@nums);   
}

## Now, i have an array or arrays, like :
#
# @collection = (
#    [1,1,1,...],
#    [4,4,4,...],
#    [123,123,123,123,...],
#    [-1,1,1,1,1,...],
# )

print "nloops : ",join(',',@{$collection[0]}),"\n";
print "lverts : ",join(',',@{$collection[1]}),"\n";
print "vertid : ",join(',',@{$collection[2]}),"\n";
print "params : ",join(',',@{$collection[3]}),"\n";

__DATA__
[1 1 1 1 1 1 ][4 4 4 4 4 4]

[ 123 123 123
  123 123 123
  123 123 123 ]

"P"

[ -1 1 1
  1 1 -1
  1 1 1 ]
[download]

I do not understand what you wrote about changing the data, but from what i posted i think you should be able to work out the seperate array issue which should put you well on your way.

---

from the frivolous to the serious

If your files get very large, then slurping them into memory to parse can be memory intensive. This solution processes the file line-by-line and uses a running buffer to parse it.

Code

Output