# Last update: 2005/12/30
# 
# Automatic namer for only-number-jpg-files and string-prefixed-numered jpg-files
#
# (p) Jerry Nagasaki
#
#
# Renames only-number- or string-prefixed-jpg-files (e. g. 01.jpg, or pp01.jpg, or ...)
# to files with 5 random leading characters
#
# INPUT:  File names like 01.jpg, 02.jpg, 03.jpg, ... or: [ABC]01.jpg, ..., whereby
#         [ABC] is argument of script call
# OUTPUT: Renamed file names to ABCD01.jpg, ABCD02.jpg, ABCD03.jpg, ... whereby
#         the first 5 characters are randomly generated per file list and a sub
#         set of [0-9][A-Z][a-z]
#
# Note:   File names smaller than 10 w/o leading zero will also be renamed to
#         ABCD0n.jpg, n = {0, 1, 2, ... , 9}
#             ^
#

# get argument for starting characters, if existing
$prefix = $ARGV[0] || "";

# maximum file numbers to search
$MAXFILES = 99;

# file extension for renaming
$FILE_EXT = ".jpg";

# definition to set length to "zero"
$code ="";

# get randomized values and continue until 5 ASCII characters got
while (length($code) < 5)
{
	$rand = chr(int(rand(1) * 256));

	# add only 0-9, A-Z, or a-z to string
	if ($rand =~ /[0-9A-Za-z]/)
	{
		$code .= $rand;
	}
}

# rename files with "'just-a-number'.jpg" to "'5-randomized-characters-plus-number'.jpg"
for ($i = 0; $i < $MAXFILES; $i++)
{
	$filename1 = $i.$FILE_EXT;		# prepare for checking for no leading "0" -> "n"
	$filename2 = "0".$i.$FILE_EXT;		# prepare for checking for leading "0"    -> "0n"
	$filename3 = "00".$i.$FILE_EXT;		# prepare for checking for leading "00"   -> "00n"
	
	# check for "n" or "0n" ...
	if ((-e $prefix.$filename1) && ($i < 10))
	{
		$newname = "$code"."0"."$filename1"; 			# add a "0", if "n.jpg"
		print "Renaming $prefix$filename1 to $newname\n";
		rename($prefix.$filename1, $newname);
	}
	
	elsif ((-e $prefix.$filename2) && ($i < 10))
	{
		$newname = "$code$filename2";
		print "Renaming $prefix$filename2 to $newname\n";	# don't add a "0", if "0n.jpg"
		rename($prefix.$filename2, $newname);
	}

	elsif ((-e $prefix.$filename2) && ($i >= 10))
	{
		$newname = "$code$filename2";
		print "Renaming $prefix$filename2 to $newname\n";	# add a "0", if "0n.jpg", n >= 10
		rename($prefix.$filename2, $newname);
	}
	
	elsif ((-e $prefix.$filename3) && ($i < 10))
	{
		$newname = "$code$filename3";
		print "Renaming $prefix$filename3 to $newname\n";	# don't add a "0", if "0n.jpg"
		rename($prefix.$filename3, $newname);
	}	
	
	elsif (-e $prefix.$filename1)
	{
		$newname = "$code$filename1";
		print "Renaming $prefix$filename1 to $newname\n";
		rename($prefix.$filename1, $newname);
	}
}