Strings Same but evaluates to false on equality?

Question

I am trying to read a file in my localhost and compare the equivalent string with another string. The contents of the strings are exactly the same and I have done the following:

$homepage = file_get_contents('./output.txt');
$input="some string"

strcmp($input,$homepage) //this statement evaluates to -1..

Where am i going wrong..? How do i cross-check whether the string read from the file is exactly same as the string to be compared..?

Here's a screen-shot with two strings echoed..

enter image description here

Looks like the strings aren't equal. Check for *hidden* chars like new lines or tabs. My guess is that the file contains a new line at the end — hek2mgl, Feb 14 '14 at 08:55
and what does `print_r($input);` and `print_r($homepage);` tell you? — Prix, Feb 14 '14 at 08:57

score 2 · Answer 1 · answered Feb 14 '14 at 08:56

2

Try this:

strcmp($input, trim($homepage));

I'm using trim() to remove leading or trailing whitespace from $homepage. As I've told in comments, I guess that there is a newline at the end of $homepage.

answered Feb 14 '14 at 08:56

hek2mgl

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score 0 · Answer 2 · answered Feb 14 '14 at 08:58

There may be a newline character present in the string that you've read from the file. The best thing to do when taking in input from an external source is to trim out trailing and leading spaces (and also filter/validate as well, but that's another issue).

e.g.

$homepage = trim(file_get_contents('./output.txt'));
$input="some string";

As a further example:

kguest@radagast:~$ php -a
Interactive mode enabled

php > $f = "  foo \n";
php > $b = "foo";
php > var_dump($f === $b);
bool(false)
php > var_dump(trim($f) === $b);
bool(true)
php > var_dump(strcmp(trim($f), $b));
int(0)
php >

Strings Same but evaluates to false on equality?

2 Answers2