How to Find a Wildcard String in a Text File in PHP

To search for a wildcard string in a text file in PHP, you need to open the text file and read its contents into a single variable with the file_get_contents function. Then you need to define a regular expression that contains the syntax for matching to the wildcard. Next you need to search the variable with the file contents for the wildcard string using either the built-in preg_match or preg_match_all function.

Instructions

1. Create a new PHP file using an editor. For example, type:

   nano wildcard.php

2. Open the text file and read the entire contents of the file into a single variable using the file_get_contents function. For example, type:

   <?php

   if (!($text = file_get_contents("myfile.txt"))) die("Could not open text file!");

3. Initialize an array that will be used to store the matches from the text file. For example, type:

   $results = array();

4. Define the wildcard string as a regular expression. For example, type:

   $wildcard = /wildcardmatch(\d\d\d)/ig;

5. Call the preg_match or preg_match_all function to match the text file contents against the wildcard regular expression. Pass the array you initialized as the third parameter and the array will be populated with the matches. Print the array with the matches if the function succeeds. For example, type:

   if (preg_match_all($wildcard, $text. $matches)) {

   print_r($matches);

   }

   ?>

References

• PHP Manual: file_get_contents
• PHP Manual: preg_match_all
• PHP Manual: print_r

Resources

• PHP Manual: Regular Expressions (Perl-Compatible)
• Regular-Expressions.info: PHP Provides Three Sets of Regular Expression Functions