print "\nThis has a \\n at the start and end of the line.\n";
print "\n\nIt might be clearer to state: \n";
print "    This has a \"\\n\" at the start and end of the line.\n";
print "\nThe trick is to put a \"\\\" in front of any \"special\" character to be printed\n";
print "A \"\$\" is also a special character.

# NOTE: so far we have done most printing using "      " and this use of the "\" for
#             "special" characters only applies to things inside of "   ", or inside of '   '.

open (INFILE, "dataFile.txt");
    # assumes that a file named "dataFile.txt" exists and has some text in it

open (INFILE, "dataFile.txt");
$lineRead = <INFILE>;
print "The line read was [$lineRead] which still has a new line character in it.\n ";
chop($lineRead);
print "The line read, [$lineRead] no longer has a new line character in it.\n";

open (INFILE2, "dataFile.txt");
$count = 1;
while ($in = <INFILE2>)
        {
           chop ($in);
           print "Line number $count is [$in].\n"
           $count = $count + 1;
         }

open (OUTFILE, ">dataOut.txt"); #opens empty file, erases old file of same name
    # File is opened and permits program to write new lines of text into file

Read from
one file, write to second

open (OUTF, ">fileOut.txt");
open (INFILE2, "dataFile.txt");
$count = 1;
while ($in = <INFILE2>)
        {
           print " read Line number $count, and wrote to fileOut.txt.\n"
           print OUTF $in;
           $count = $count + 1;
         }

Exercise: See if you can write a program to read a number from a file and then have the user keep guessing the number till they get it right.   Click here for the answer!

$inPath = "dataFile.txt";
open (INF, $inPath) or die "could not open $inPath";

$outPathPart = "OutFile_";

$count = 1;
while ($in = <INF>)
        {
           $outPath = $outPathPart."count";  # the period between the two text lines appends
                                                                #    the first two the second, e.g OutFile_1
           open (OUTF, $outPath) or die "Could not open $outPath!";
           print OUTF $in;
           print " read Line number $count, and wrote to $outPath.\n"
           $count = $count + 1;
           close (OUTF); # close the file when you are through writing to it.
         }

NOTES:
The Perl statement : open (OUTF, ">outfile.txt"); creates a new, empty file. If a file of the same name aleady existed, it is deleted.   To open an existing file so that the program can add lines to the bottom of the file use this Perl statement: open(OUTF,">>outfile.txt);

Note the use of    ">>"    rather than just   ">"

Write a Perl program that will ask any number of users for their name and append each name to the bottom of a previously existing output file.   Click here for answer.