String Comparison in php is not working

Question

I am trying to open a file and compare each line to a string to see if they are same or not, but it's not working, here is the code.

$toSearch="moizhusnain@hotmail.com";
$textData=array();
$fla=FALSE;
$file=fopen('text.txt','r') or die('Unable to open file.');
while(!feof($file))
{
  $textData[]=fgets($file);
}
fclose($file);
for($i=0;$i<count($textData);$i++)
{
  echo $textData[$i]."<br/>";
  if (strcmp($toSearch,$textData[$i])==0)
  {
      echo "Yes";
  }
}

I assume, there is a newline (`\n`) at the end of each `$textData[$i]`, so it probably won't match? Why do you use strcmp anyway? — Jakumi, Aug 10 '16 at 06:02
1. `strcmp` is case sensitive. 2. use `===` comparison operator — rokas, Aug 10 '16 at 06:02
Simple Way `shell_exec("grep -h 'moizhusnain@hotmail.com' filename")` if you get output then exist else no match found — Saurabh, Aug 10 '16 at 06:02
Instead of loading your data line for line into an array, do the comparison directly in `while`. What you are doing is overkill and you are wasting memory and cpu. — Charlotte Dunois, Aug 10 '16 at 06:04
@Saurabh `shell_exec` isn't by default simpler ... especially if you aren't allowed to call it (some hosters are very picky) — Jakumi, Aug 10 '16 at 06:04
@CharlotteDunois you are probably meaning well, but I just assumed this is a minimal example and OP didn't bother to optimize it further. — Jakumi, Aug 10 '16 at 06:05
@Jakumi Yes that may be the case. But if it available we could use it to search for string in file. — Saurabh, Aug 10 '16 at 06:06
I have actually tried that too, means in the while loop, and i have also tried '===' but it was not showing the desired results. — Moiz Husnain, Aug 10 '16 at 06:12

score 3 · Answer 1 · edited Aug 10 '16 at 06:04

3

Try this

if (strcasecmp ($toSearch,$textData[$i])==0){ //case insensitive comparison
      echo "Yes";
}

Doc: http://php.net/manual/en/function.strcasecmp.php

edited Aug 10 '16 at 06:04

rokas

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answered Aug 10 '16 at 06:02

jonju

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This presumes that the problem is case-sensitivity. What if it is not? Doesn't a trailing newline seem more obvious (not "visual" to casual inspection, whereas a n uppercase letter tends to stick out when you say to yourself "why aren't these two things the same"). Still, three votes for it and counting. – Bill Woodger Aug 10 '16 at 06:07
it's still not working. It actually works when i just compare two stings but unfortunately in this case when i compare a string with an element of array this is not working. – Moiz Husnain Aug 10 '16 at 06:08
Try to reproduce the problem before you write an answer. This problem has nothing to do with case sensivity – Daniel Aug 10 '16 at 06:09

Anant Kumar Singh · Accepted Answer · 2021-08-23T04:51:40.360

2

My Assumption:-(your text file looks like this)

moizhusnain@hotmail.com
dfgfdgmoizhusnain111@hotmail.com
moidgdfdffdgzhusnain@hotmail.com
moizdsfdsfdsdfhusnain@hotmail.com

According to above assumption code should be:-

<?php
error_reporting(E_ALL);
ini_set('display_errors',1);
$toSearch="moizhusnain@hotmail.com";
$textData = file('text.txt',FILE_IGNORE_NEW_LINES); // use file() function with ignoring new lines of your text file
foreach($textData as $textDat){ // use foreach() rather than for() loop
  if ($toSearch == $textDat){
    echo "Yes";
  }
}
?>

Reference:-

http://php.net/manual/en/function.file.php

Note:- If this works for you that simply means that new lines of your text-file are restricting your code to work as well as strcmp() is not needed actually.

edited Aug 23 '21 at 04:51

answered Aug 10 '16 at 06:11

Anant Kumar Singh

68,309
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Yeah! it worked, but i want to ask what `
` do because i'm just newbie to web programming.
– Moiz Husnain Aug 10 '16 at 06:19
@MoizHusnain check this link for your question:-http://stackoverflow.com/questions/4756842/what-does-php-echo-pre-echo-pre-mean – Anant Kumar Singh Aug 10 '16 at 06:20
@Daniel the problem was with the `\n` – Moiz Husnain Aug 10 '16 at 06:22

score 0 · Answer 3 · edited May 23 '17 at 12:22

0

While jonju has made a working example that fixes the problem using another approach, it can be fixed with the existing code, merely by using this RegEx (stolen from here)

$string = trim(preg_replace('/\s\s+/', ' ', $string));

The following code works:

<?php
$toSearch="moizhusnain@hotmail.com";
$textData=array();
$fla=FALSE;
$file=fopen('text.txt','r') or die('Unable to open file.');
while(!feof($file))
{
  $textData[]=trim(preg_replace('/\s\s+/', ' ', fgets($file)));;
}
fclose($file);
for($i=0;$i<count($textData);$i++)
{

    if (strcmp($toSearch,$textData[$i])==0)
    {
        echo "Yes";
    }
}
?>

edited May 23 '17 at 12:22

Community

1
1

answered Aug 10 '16 at 06:25

Daniel

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@Anant It's my first question actually, i tired to mark both answers but when i marked the second one your answer was automatically unmarked, it was not my intention. – Moiz Husnain Aug 10 '16 at 06:57
@MoizHusnain it's ok. I understand. Sorry if my wordings hurted you. – Anant Kumar Singh Aug 10 '16 at 08:58

String Comparison in php is not working

3 Answers3