CODEWITHSUNDEEP
phpstring
user1951615
user1951615

Reputation: 141

PHP string goes empty unless echoed

I have the following test program:

#!/usr/bin/php
<?php
echo "Starting\n";

# Now read the file.
#
$file_pn = "contact.txt";
$fh = fopen($file_pn, 'r');
while (!feof($fh)) {
   $line = fgets($fh);
   $trimmed = trim($line);
   echo "trimmed = <" . $trimmed . ">\n";
   if (preg_match('/^\s*$/', $trimmed)) {
      echo "Looks blank: trimmed = <" . $trimmed . ">\n";
      #continue;
   }
}
fclose($fh);
?>

The file being read has some blank lines and some non-blank lines. As shown here, it acts as one would expect: only the lines that are actually blank receive the "Looks blank" message, and trimmed = <>. But if I comment out the echo statement in line 12 and run the script again, $trimmed always appears to be the empty string when we get to the if statement. It is as if $trimmed gets clobbered unless it has been echoed. How can this be?

Upvotes: 2

Views: 65

Answers (1)

calcinai
calcinai

Reputation: 2617

I don't think you need to be using a regex there. If the line is only whitespace to begin with, trim() will make it empty.

Try:

if (empty($trimmed)) {

It behaves as expected for me - since you're now not echoing any lines that aren't empty, your output will only show a heap of empty lines

$ ./test|wc -l
18
$ nano test #comment line 12
$ ./test|wc -l
6

Upvotes: 2

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