This converts all the data lines from a filehandle (I use DATA) to 7bit binary strings.

while (my $line = <DATA>){
   chomp $line;
   for (split//, $line) {
       print unpack "b7", $_;
   }
   print "\n";
}
__DATA__
Hello
World!
-JAPH
[download]

First we chomp off the newline. Then we get to the guts of it. How this works is the split//, $line part splits our line on null characters which generates an array/list which contains all the characters in line with each single character stored as an element of this array. The for iterates over this array and assigns each element to the magical $_ variable. We then use unpack to generate our bitstring. The "b7" specifies a 7 bit template which is sufficient for the ASCII char set. We then print each char (now a 7bit bitstring)in turn. We need to print a newline to maintain our file structure

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

• The $/ variable determines what constitutes a "line" read by the <> operator. (See perlman:perlvar).
• A null first argument to split breaks up the second argument into individual characters.¹ (See perlman:perlfunc.)
• The ord and chr functions essentially complement each other.
• map is a powerful way to construct loops in Perl, in a style reminiscent of functional programming languages. (See perlman:perlfunc.)
• To construct a string out of an array's elements, using a given string as separator, use join. In this sense, it's complementary to split. (See perlman:perlfunc also.)
• The -e option to Perl allows you to execute a script directly from the command line. (See perlman:perlrun.)

HTH

¹That gets tricky when dealing with multi-byte encodings, but ignore that for the moment....

umm, I want to lets say take message.txt and convert its contents to ascii code values, only instead of converting for example e's to 101 I want the binary 1100101.

for the 8 bit version (e.g. e becomes 01100101 (depending on arch)), the following should work (not tested, but should work) :


while (<DATA>) {
    print unpack("b*",$_);
}
__END__
Just Another Perl Hacker
[download]

---

may the foo be with you

And this converts it back again

while (my $line = <DATA>){
   chomp $line;
   print pack "b7", $1 while $line =~ m/(.{7})/g;
   print "\n";
}
__DATA__
00010011010011001101100110111111011
111010111110110100111001101100100111000010
10110100101001100000100001010001001
[download]

If you don't understand pack and unpack don't worry - neither do I really!

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Do I have to use 7bit binary?

The answer is no but it does get a little more complex. Why don't you have a play with it and see?

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print