purge.sh

#!/usr/bin/php
<?php
/**
 * This works for the following nginx configuration:
 *
 * fastcgi_cache_path [..] levels=1:2 [..];
 * fastcgi_cache_key  "$scheme://$host$request_uri";
 *
 * Make this file executable
 * `chmod +x /path/to/this/file`
 * and use like this
 * `/path/to/this/file http://example.com/uri/`
 */

$url = isset( $argv[1] ) ? $argv[1] : '';

$url = trim( $url, '/' );

if ( empty( $url ) ) {
    die('Must provide a URL');
}

$url .= '/';

purge( $url );

function purge( $url ) {

	$frag = parse_url( $url );

	// edit as needed according to the first value in {proxy|fastcgi}_cache_path
	$cache_root = '/etc/nginx/cache/';
	$query      = isset( $frag['query'] ) ? "?{$frag['query']}" : '';

	// edit as needed according to the value in {proxy|fastcgi}_cache_key
	$hash       = md5( "{$frag['scheme']}://{$frag['host']}{$frag['path']}{$query}" );

	// edit as needed according to the levels value in {proxy|fastcgi}_cache_path
	$hash_path  = $cache_root . substr( $hash, -1 ) .'/'. substr( $hash, -3, 2 ) .'/'. $hash;

	if ( ! is_file( $hash_path ) ) {
		echo "No cache set [{$url}::{$hash_path}]\n";
		return;
	}
	if ( unlink( $hash_path ) ) {
		echo "Cache removed [{$url}::{$hash_path}]\n";
	} else {
		echo "Cache could not be removed [{$url}::{$hash_path}]\n";
	}
}