xdiff Functions
PHP Manual

xdiff_string_diff

Make unified diff of two strings

Description

string xdiff_string_diff(
    string $old_data,
    string $new_data,
    int $context = 3,
    bool $minimal = false
)

Makes an unified diff containing differences between old_data string and new_data string and returns it. The resulting diff is human-readable. An optional context parameter specifies how many lines of context should be added around each change. Setting minimal parameter to true will result in outputting the shortest patch file possible (can take a long time).

Parameters

old_data

First string with data. It acts as "old" data.

new_data

Second string with data. It acts as "new" data.

context

Indicates how many lines of context you want to include in the diff result.

minimal

Set this parameter to true if you want to minimalize the size of the result (can take a long time).

Return Values

Returns string with resulting diff or false if an internal error happened.

Examples

Example #1 xdiff_string_diff example

The following code makes unified diff of two articles. 

<?php
$old_article = file_get_contents('./old_article.txt');
$new_article = $_REQUEST['article']; /* Let's say that someone pasted a new article to html form */

$diff = xdiff_string_diff($old_article, $new_article, 1);
if (is_string($diff)) {
    echo "Differences between two articles:\n";
    echo $diff;
}

?>

Notes

Note:

This function doesn't work well with binary strings. To make diff of binary strings use xdiff_string_bdiff/xdiff_string_rabdiff.

See Also

  • xdiff_string_patch