PHP to search within txt file and echo the whole line

Question

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.

Answer 1

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";
}

Answer 2

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.

Answer 3

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.