PHP - Find a string in file then show it's line number - php

Question

I have an application which needs to open the file, then find string in it, and print a line number where is string found.
For example, file example.txt contains few hashes:
APLF2J51 1a79a4d60de6718e8e5b326e338ae533 EEQJE2YX
66b375b08fc869632935c9e6a9c7f8da O87IGF8R
c458fb5edb84c54f4dc42804622aa0c5 APLF2J51 B7TSW1ZE
1e9eea56686511e9052e6578b56ae018 EEQJE2YX
affb23b07576b88d1e9fea50719fb3b7
So, I want to PHP search for "1e9eea56686511e9052e6578b56ae018" and print out its line number, in this case 4.
Please note that there are will not be multiple hashes in file.
I found a few codes over Internet, but none seem to work.
I tried this one:
<?PHP
$string = "1e9eea56686511e9052e6578b56ae018";
$data = file_get_contents("example.txt");
$data = explode("\n", $data);
for ($line = 0; $line < count($data); $line++) {
if (strpos($data[$line], $string) >= 0) {
die("String $string found at line number: $line");
}
}
?>
It just says that string is found at line 0.... Which is not correct....
Final application is much more complex than that...
After it founds line number, it should replace string which something else, and save changes to file, then goes further processing....
Thanks in advance :)

Answer 1

An ultra-basic solution could be:
$search = "1e9eea56686511e9052e6578b56ae018";
$lines = file('example.txt');
$line_number = false;
while (list($key, $line) = each($lines) and !$line_number) {
$line_number = (strpos($line, $search) !== FALSE) ? $key + 1 : $line_number;
}
echo $line_number;
A memory-saver version, for larger files:
$search = "1e9eea56686511e9052e6578b56ae018";
$line_number = false;
if ($handle = fopen("example.txt", "r")) {
$count = 0;
while (($line = fgets($handle, 4096)) !== FALSE and !$line_number) {
$count++;
$line_number = (strpos($line, $search) !== FALSE) ? $count : $line_number;
}
fclose($handle);
}
echo $line_number;

Answer 2

function get_line_from_hashes($file, $find){
$file_content = file_get_contents($file);
$lines = explode("\n", $file_content);
foreach($lines as $num => $line){
$pos = strpos($line, $find);
if($pos !== false)
return $num + 1
}
return false
}
get_line_from_hashes("arquivo.txt", "asdsadas2e3xe3ceQ#E"); //return some number or false case not found.

Answer 3

If you need fast and universal solution that working also for finding line number of multiline text in file, use this:
$file_content = file_get_contents('example.txt');
$content_before_string = strstr($file_content, $string, true);
if (false !== $content_before_string) {
$line = count(explode(PHP_EOL, $content_before_string));
die("String $string found at line number: $line");
}
FYI Works only with PHP 5.3.0+.

Answer 4

$pattern = '/1e9eea56686511e9052e6578b56ae018/';
if (preg_match($pattern, $content, $matches, PREG_OFFSET_CAPTURE)) {
//PREG_OFFSET_CAPTURE will add offset of the found string to the array of matches
//now get a substring of the offset length and explode it by \n
$lineNumber = count(explode("\n", substr($content, 0, $matches[0][1])));
}

Answer 5

If the file is not extremely large then just read the file into an array file, search for the word preg_grep, get the index key for that line and add 1 since the array starts at 0:
$string = "1e9eea56686511e9052e6578b56ae018";
echo key(preg_grep("/$string/", file("example.txt"))) + 1;

Answer 6

I found this to work great and be very efficient; Simply explode the file by each line and search through the array for your search terms like so:
function getLineNum($haystack, $needle){
# Our Count
$c = 1;
# Turn our file contents/haystack into an array
$hsarr = explode("\n", $haystack);
# Iterate through each value in the array as $str
foreach($hsarr as $str){
# If the current line contains our needle/hash we are looking for it
# returns the current count.
if(strstr($str, $needle)) return $c;
# If not, Keep adding one for every new line.
$c++;
}
# If nothing is found
if($c >= count($hsarr)) return 'No hash found!';
}
EDIT: Looking through the other answers, I realize that Guilherme Soares had a similar approach but used strpos, which in this case doesnt work. So I made a few alterations with his idea in mind here:
function getLineNum($haystack, $needle){
$hsarr = explode(PHP_EOL, $haystack);
foreach($hsarr as $num => $str) if(strstr($str, $needle)) return $num + 1;
return 'No hash found!';
}
Live Demo: https://ideone.com/J4ftV3