How Can I Efficiently Search and Extract Specific Lines from a Text File in PHP?

Searching and Extracting Lines from a Text File in PHP

Searching through large text files for specific data can be a crucial task in PHP programming. This is especially relevant when dealing with log files, databases, or other text-based formats. By leveraging the power of PHP's file handling and regular expression capabilities, you can easily create scripts that locate and extract the desired information.

Searching for Specific Lines in a Text File

Consider the following scenario: You have a text file named "numorder.txt" containing data like this:

2 aullah1
7 name
12 username

Your objective is to search within this file for the entry "aullah1" and retrieve the entire line it belongs to. Here's how you would approach this problem:

1. Open the Text File: Use the fopen() function to establish a connection to the text file.
2. Search for the Pattern: Employ the preg_match() function to define a regular expression pattern to match the desired text.
3. Extract the Line: Once the matching pattern is found, use fgets() to read the entire line from the file.

PHP Code Example:

The following PHP code demonstrates the process described above:

<?php
$filename = 'numorder.txt';
$search_term = 'aullah1';

$file_handle = fopen($filename, 'r');
while (!feof($file_handle)) {
    $line = fgets($file_handle);
    if (preg_match("/.*$search_term.*/", $line)) {
        echo $line;
        break;
    }
}
?>

This code will read the "numorder.txt" file line by line and search for the string "aullah1" using the regular expression pattern. Once the match is found, it will echo the entire line containing the matching text.

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