Pretty-print JSON from any URL PHP's file_get_contents can reach

jsonprint

#!/usr/bin/php
<?php

function usage() {
	echo "Usage: " . $_SERVER['argv'][0] . " [-v] URL\n";
	echo "\nPretty-prints JSON output from a URL.";

	echo "\n\t-v\tDecode JSON and use var_dump to display result\n";
}

/**
 * Indents a flat JSON string to make it more human-readable.
 * Stolen from http://recursive-design.com/blog/2008/03/11/format-json-with-php/
 * and adapted to put spaces around : characters.
 *
 * @param string $json The original JSON string to process.
 *
 * @return string Indented version of the original JSON string.
 */
function indent($json) {

	$result      = '';
	$pos         = 0;
	$strLen      = strlen($json);
	$indentStr   = '  ';
	$newLine     = "\n";
	$prevChar    = '';
	$outOfQuotes = true;

	for ($i=0; $i<=$strLen; $i++) {

		// Grab the next character in the string.
		$char = substr($json, $i, 1);

		// Put spaces in front of :
		if ($outOfQuotes && $char == ':' && $prevChar != ' ') {
			$result .= ' ';
		}
		
		if ($outOfQuotes && $char != ' ' && $prevChar == ':') {
			$result .= ' ';
		}

		// Are we inside a quoted string?
		if ($char == '"' && $prevChar != '\\') {
			$outOfQuotes = !$outOfQuotes;

			// If this character is the end of an element, 
			// output a new line and indent the next line.
		} else if(($char == '}' || $char == ']') && $outOfQuotes) {
			$result .= $newLine;
			$pos --;
			for ($j=0; $j<$pos; $j++) {
				$result .= $indentStr;
			}
		}

		// Add the character to the result string.
		$result .= $char;
		
		// If the last character was the beginning of an element, 
		// output a new line and indent the next line.
		if (($char == ',' || $char == '{' || $char == '[') && $outOfQuotes) {
			$result .= $newLine;
			if ($char == '{' || $char == '[') {
				$pos ++;
			}

			for ($j = 0; $j < $pos; $j++) {
				$result .= $indentStr;
			}
		}

		$prevChar = $char;
	}

	return $result;
}

$url = null;
$asVarDump = false;

foreach ($_SERVER['argv'] as $arg) {
	if ($arg == '-v') {
		$asVarDump = true;
	} else if ($arg == '--help') {
		usage();
		exit;
	} else {
		$url = $arg;
	}
}

if (!$url) {
	usage();
	exit(-1);
}

if ($asVarDump) {
	$result = json_decode(file_get_contents($url));
	var_dump($result);
} else {
	$result = indent(file_get_contents($url));
	echo $result;
}
echo "\n";