PHP to search within txt file and echo the whole line

Using php, I'm trying to create a script which will search within a text file and grab that entire line and echo it.

I have a text file (.txt) titled "numorder.txt" and within that text file, there are several lines of data, with new lines coming in every 5 minutes (using cron job). The data looks similar to:

2 aullah1
7 name
12 username

How would I go about creating a php script which will search for the data "aullah1" and then grab the entire line and echo it? (Once echoed, it should display "2 aullah1" (without quotations).

If I didn't explain anything clearly and/or you'd like me to explain in more detail, please comment.

And a PHP example, multiple matching lines will be displayed:

<?php
$file = 'somefile.txt';
$searchfor = 'name';

// the following line prevents the browser from parsing this as HTML.
header('Content-Type: text/plain');

// get the file contents, assuming the file to be readable (and exist)
$contents = file_get_contents($file);
// escape special characters in the query
$pattern = preg_quote($searchfor, '/');
// finalise the regular expression, matching the whole line
$pattern = "/^.*$pattern.*\$/m";
// search, and store all matching occurences in $matches
if(preg_match_all($pattern, $contents, $matches)){
   echo "Found matches:\n";
   echo implode("\n", $matches[0]);
}
else{
   echo "No matches found";
}

Do it like this. This approach lets you search a file of any size (big size won't crash the script) and will return ALL lines that match the string you want.

<?php
$searchthis = "mystring";
$matches = array();

$handle = @fopen("path/to/inputfile.txt", "r");
if ($handle)
{
    while (!feof($handle))
	{
        $buffer = fgets($handle);
		if(strpos($buffer, $searchthis) !== FALSE)
			$matches[] = $buffer;
    }
    fclose($handle);
}

//show results:
print_r($matches);
?>

Note the way strpos is used with !== operator.

Using file() and strpos():

<?php
// What to look for
$search = 'foo';
// Read from file
$lines = file('file.txt');
foreach($lines as $line)
{
  // Check if the line contains the string we're looking for, and print if it does
  if(strpos($line, $search) !== false)
    echo $line;
}

When tested on this file:

> foozah
> barzah
> abczah

It outputs:

> foozah

---

Update:
To show text if the text is not found, use something like this:

<?php
$search = 'foo';
$lines = file('file.txt');
// Store true when the text is found
$found = false;
foreach($lines as $line)
{
  if(strpos($line, $search) !== false)
  {
    $found = true;
    echo $line;
  }
}
// If the text was not found, show a message
if(!$found)
{
  echo 'No match found';
}

Here I'm using the $found variable to find out if a match was found.

$searchfor = $_GET['keyword'];
$file = 'users.txt';

$contents = file_get_contents($file);
$pattern = preg_quote($searchfor, '/');
$pattern = "/^.*$pattern.*\$/m";

if (preg_match_all($pattern, $contents, $matches)) {
    echo "Found matches:<br />";
    echo implode("<br />", $matches[0]);
} else {
    echo "No matches found";
    fclose ($file); 
}

looks like you're better off systeming out to system("grep \"$QUERY\"") since that script won't be particularly high performance either way. Otherwise http://php.net/manual/en/function.file.php shows you how to loop over lines and you can use http://php.net/manual/en/function.strstr.php for finding matches.

one way...

$needle = "blah";
$content = file_get_contents('file.txt');
preg_match('~^(.*'.$needle.'.*)$~',$content,$line);
echo $line[1];

though it would probably be better to read it line by line with fopen() and fread() and use strpos()

Slightly modified approach of the Upvoted answer to support multiple directories and variable keywords through a GET variable (if you wish to do it that way)

if (isset($_GET["keyword"])){

   foreach(glob('*.php') as $file) { 

      $searchfor = $_GET["keyword"];
      
      // the following line prevents the browser from parsing this as HTML.
      header('Content-Type: text/plain');
      
      // get the file contents, assuming the file to be readable (and exist)
      $contents = file_get_contents($file);
      // escape special characters in the query
      $pattern = preg_quote($searchfor, '/');
      // finalise the regular expression, matching the whole line
      $pattern = "/^.*$pattern.*\$/m";
      // search, and store all matching occurences in $matches
      if(preg_match_all($pattern, $contents, $matches)){
         echo "Found matches:\n";
         echo $file. "\n";
         echo implode("\n", $matches[0]);
         echo "\n\n";
      }
      else{
      //  echo "No matches found";
      }
   }
}