# The following illustrates how to read a file (on the server) line-by-line using PHP.

# First, open the file...
# The 'r' means the file is being opened for reading.
$fp = fopen("some_file.txt", 'r');

# Check to see if the file opened successfully. *Always do this!*
# The code below terminates the script if the file didn't open. This might not always be
# the most appropriate choice. Often it is necessary to use an 'else' clause on the 'if'
# for the "normal" flow, and put other non-trivial error handling inside 'if' clause.
if (!$fp) {
  echo "<p><b>Error: Cannot open file...</b></p>";
  exit;
}

# Keep reading the file as long as you aren't at the end-of-file.
while (!feof($fp)) {

    # Function fgets() gets a single line of any length from the file. The '\n' character
    # is still at the end of the line. Normally you want to throw that character away. The
    # rtrim() function does a right-hand (i.e., the end of the string) trim of "whitespace"
    # characters. This also removes trailing spaces or tabs (normally a good thing).
    $line = rtrim(fgets($fp));

    # If fgets() returns False (due to an error), rtrim() will return an empty value. In
    # that case, just iterate around the loop again. [Is this really smart?]
    if (empty($line)) continue;

    # Now process the line...
}


# Finally, close the file...
fclose($fp);