This example builds a very simple version of grep. It accepts the path to the file to search as an argument and an arbitrary number of search terms as arguments. It outputs lines that contain one or more of the search terms (no regex!). The search terms are highlighted in yellow in the output.

Usage:

script.php "search term 1" "search term 2" /path/to/file

#Features used

This recipie uses the following Macrame features:

• arguments
• text
• file

#Example

#!/usr/bin/env php
<?php
require __DIR__ . '/vendor/autoload.php';

use Gbhorwood\Macrame\Macrame;

$macrame = new Macrame("simple grep");

if($macrame->running()) {

    /**
     * Get the last positional argument in the list, which is the file to inspect
     */
    $file = $macrame->args('positional')->last();

    /**
     * Get all the other positional arguments before the last one, the terms to search
     */
    $searches = array_slice($macrame->args('positional')->all(), 0, -1);

    /**
     * Convert search terms to a preg-style regex
     */
    $searchesRegex = '/'.join('|', $searches).'/';

    /**
     * Get the patterns and replacemens so preg_replace() can highlight each search term
     */
    $patterns = array_map(fn($s) => "/$s/", $searches);
    $replacements = array_map(fn($s) => $macrame->text($s)->colour('yellow')->get(), $searches);

    /**
     * Iterate over each line in file using byLine()'s generator.
     * Test for the existence of any of the search terms. Replace the search term
     * with the ANSI-coloured search term using preg_replace(). Output using
     * text's write() method.
     */
    foreach($macrame->file($file)->byLine() as $line) {
        if(preg_match($searchesRegex, $line) > 0) {
            $macrame->text(preg_replace($patterns, $replacements, $line))->write();
        }
    }

    // exit cleanly
    $macrame->exit();
}

#Walkthrough

The first step is to get the command line arguments. There are two types of arguments: the file to search on, which is always the last positional argument, and the arbitrary number of search terms, which come before the file.

Getting the path to the file is done using the args object’s last() method.

$file = $macrame->args('positional')->last();

To get the arbitrary number of search terms, the all() method for the args object is used to get all the arguments as an array. Then array_slice() is applied so that all the arguments except the last one are assigned to the $searches variable.

$searches = array_slice($macrame->args('positional')->all(), 0, -1);

Since this script uses preg_match(), the array of search terms in $searches needs to be converted into a regular expression string. This is done wiht

$searchesRegex = '/'.join('|', $searches).'/';

The result in $searchesRegex is a string that looks like /term1|term2|term3.

Highlighting of the search terms in the output is done with preg_replace(), which requires an array of patterns to match and a matching array of strings to replace each pattern with.

$patterns = array_map(fn($s) => "/$s/", $searches);
$replacements = array_map(fn($s) => $macrame->text($s)->colour('yellow')->get(), $searches);

The array of patterns is an array containing each search term delimited as a regular expression. ie. if one of the search terms is bicycle, the pattern is /bicycle/.

The array of replacements for the patterns is the search term with ANSI colourization tags added to them to make them yellow in the terminal. This is done using the colour() method on text(). The Macrame text object is returned as a string using get() and assigned to the $replacements array.

Finally, the contents of the file is iterated over using the byLine() method from Macrame’s file object. The byLine() method returns a generator that can be used in a foreach() loop just as an array would. Since the byLine() method does not read in the entire contents of the file, it can be used with files of very large sizes without worrying about system memory.

Inside the loop, preg_match() is applied to each line to determine if it contains any of the search terms listed in $searchesRegex.

If one or more terms is found, the search terms in the line are replaced with colourized versions using preg_replace() and the string is output to the console using the write() method of Macrame’s text object.

foreach($macrame->file($file)->byLine() as $line) {
    if(preg_match($searchesRegex, $line) > 0) {
        $macrame->text(preg_replace($patterns, $replacements, $line))->write();
    }