Shell Programming and Scripting

split -1000 testdata testdata_

testdata_aa
testdata_bb
testdata_cc

testdata1.snd
testdata2.snd
testdata3.snd

ls -1 testdata_* | sort -t "_" -n -k2,2 -k3,3 -k4,4

k=1
for i in $( ls test* )
do
mv -f $i ${i%%_*}$k.snd
((k++))
done

nawk -v f="$1" -v l="${2-1}" 'BEGIN{n=1}
{
file=sprintf("%s%s.snd",f,n)
print $0 >> file
if(NR % l ==0)
{
	file=sprintf("%s%s.snd",f,n)
	n++
}
}' yourfile

my $n=1;
my ($file,$line)=@ARGV;
$line||=1;
open FH,"<$file";
my $outfile=sprintf("%s%s.snd",$file,$n);
open OFH,">>$outfile";
while(<FH>){
        print OFH $_;
        if ($. % $line eq '0'){
                $n++;
                $outfile=sprintf("%s%s.snd",$file,$n);
                open OFH,">>$outfile";
        }
}