PHP string comparison. Regex - php

Question

We are trying to display whether a file contains a specific string or not:
Here we read the file:
$myFile = "filename.txt";
$fh = fopen($myFile,'r');
$theData = fread($fh, filesize("filename.txt"));
fclose($fh);
filename.txt contains "Offline"
Here we are trying to compare the strings:
if(strcmp($theData,"Online")==0){
echo "Online"; }
elseif(strcmp($theData,"Offline")==0) {
echo "Offline"; }
else {
echo "This IF is not working." }
We have tried using regular if without the strcomp, but it did not work either. I'm thinking that an IF cannot compare the results from the fread to a regular string. Perhaps we will need to try another method.
Any Ideas?

Answer 1

Use preg_match()
$string = "your-string";
$pattern = "/\boffline\b/i";
// The \b in the pattern indicates a word boundary, so only the distinct
// word "offline" is matched; if you want to match even partial word "offline"
// within some word, change the pattern to this /offline/i
if(preg_match($pattern, $string)) {
echo "A match was found.";
}
You can use strpos() as well (it is faster in this case)
$string = 'your-stringoffline';
$find = 'offline';
$pos = strpos($string, $find);
if($pos !== false){
echo "The string '$find' was found in the string '$string' at position $pos";
}else{
echo "The string '$find' was not found in the string '$string'";
}

Answer 2

regex is very slow when used to search in long strings. use strpos
$strFile = file_get_contents("filename.txt"); // load file
if(strpos($strFile, 'Online')!==false){ // check if "Online" exists
echo "We are Online";
}
elseif(strpos($strFile, 'Offline')!==false){ // check if "Offline" exists
echo "We are Offline";
}
else{ // other cases
echo "Status is unknown";
}

Answer 3

I put another way to do that (depending what it is inside the file), although it is not the best it may be useful in some circumstances
if (exec("grep Offline filename.txt") === 'Offline')
echo 'Offline';
else
echo 'Online';
Byee

Answer 4

Are you checked the value contains in $theData ?
Try something like this:
if(strcmp($theData,"Online") === 0)
echo $theData." is equal to string Online using case sensisive";
else if(strcmp($theData,"Offline") === 0)
echo $theData." is equal to string Offline using case sensisive";
else
echo $theData." This IF is not working.";
Here the doc for more infos: http://php.net//manual/en/function.strcmp.php
Or using the hex494D49's method: (Not tested)
function isStringAreTheSame($initialString, $stringToCompare) {
$pattern = "/\b".$initialString."\b/";
return preg_match($pattern, $stringToCompare);
}