Random file generator code?

Question

Does anyone have a simple shell script or c program to generate random files of a set size with random content under linux?

Answer 1

How about:

head -c SIZE /dev/random > file

Answer 2

Python. Call it make_random.py

#!/usr/bin/env python
import random
import sys
import string
size = int(sys.argv[1])
for i in xrange(size):
    sys.stdout.write( random.choice(string.printable) )

Use it like this

./make_random 1024 >some_file

That will write 1024 bytes to stdout, which you can capture into a file. Depending on your system's encoding this will probably not be readable as Unicode.

Answer 3

Here's a quick an dirty script I wrote in Perl. It allows you to control the range of characters that will be in the generated file.

#!/usr/bin/perl

if ($#ARGV < 1) { die("usage: <size_in_bytes> <file_name>\n"); }

open(FILE,">" . $ARGV[0]) or die "Can't open file for writing\n";

# you can control the range of characters here
my $minimum = 32;
my $range = 96;

for ($i=0; $i< $ARGV[1]; $i++) {
    print FILE chr(int(rand($range)) + $minimum);
}

close(FILE);

To use:

./script.pl file 2048

---

Here's a shorter version, based on S. Lott's idea of outputting to STDOUT:

#!/usr/bin/perl

# you can control the range of characters here
my $minimum = 32;
my $range = 96;

for ($i=0; $i< $ARGV[0]; $i++) {
    print chr(int(rand($range)) + $minimum);
}

Warning: This is the first script I wrote in Perl. Ever. But it seems to work fine.