topx.pl

取出一个文件的前n行

#!/usr/bin/perl

my $file;
my $number;
my $count = 0;
if($#ARGV < 1){
	print"$#ARGV \n";
	die"$!,Usage: perl topx.pl <filename> <number> \n";
}
else{
	$file = $ARGV[0];
	$number = $ARGV[1];
	print"$file,	$number \n";
}
print"Extracting the top $number from $file... \n";
open(DST, ">$file.top$number") or die"Cannot open file \"$file.top$number\" to write!";
open(SRC, $file) or die"Cannot open the source file $file!";

while (($line=<SRC>) && ($count < $number)){
	print(DST $line);
	$count++;
	#print "$count,	 $number; \n";
}
close(SRC);