Parsing time format - php

Question

How do I calculate the input to time in seconds, when the input is in different formats as shown in the example output below?
With this format, all parts are optional:
5d 4h 3m 2s -> 5 days, 4 hours, 3 minutes and 2 seconds
4h 2s -> 4 hours and 2 seconds
3m -> 3 minutes
With this format, parts are sometimes optional:
05: 04: 03: 02 -> 5 days, 4 hours, 3 minutes and 2 seconds
4:03:02 -> 4 hours, 3 minutes and 2 seconds
05: 00: 03: 02 -> 5 days, 3 minutes and 2 seconds
02 -> 2 seconds
I'd like to get this output:
> php time.php 1d 6h 20m 2s
> 109.202 seconds
> php time.php 3:50
> 230 seconds
> php time.php 4: 23: 45: 02
> 431.102 seconds
> php time.php 23m
> 1.380 seconds
So far I made it possible to convert input seconds to a time format, but after 5 hours of trying to make the above question work I kind of gave up:
<?php
$setTime = $argv[1];
function format_time($t,$f=':') {
return sprintf("%02d%s%02d%s%02d", floor($t/3600), $f, ($t/60)%60, $f, $t%60);
}
echo format_time($setTime);
?>

Answer 1

You could use preg_match_all to split the input into pairs of numbers and suffixes and then iterate those to count the number of seconds:
function seconds($input) {
preg_match_all("/(\d+)(\S)/", "$input:", $matches, PREG_SET_ORDER);
$letters = "smhd";
$durations = ["s" => 1, "m" => 60, "h" => 60*60, "d" => 60*60*24];
$seconds = 0;
foreach (array_reverse($matches) as list($all, $num, $code)) {
$i = strpos($letters, $code);
if ($i === false) $code = $letters[$i = 0];
$letters = substr($letters, $i+1);
$seconds += $durations[$code] * $num;
}
return $seconds;
}
function test($input) {
$seconds = number_format(seconds($input));
echo "$input => $seconds seconds\n";
}
test("1d 6h 20m 2s"); // 109.202 seconds
test("3:50"); // 230 seconds
test("4: 23: 45: 02"); // 431.102 seconds
test("23m"); // 1.380 seconds
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Answer 2

The following might be total overkill, but it also might illustrate how you can approach this problem if you want your code to be extendable and easy to reuse:
<?php
declare(strict_types=1);
error_reporting(-1);
ini_set('display_errors', 'On');
interface TimeStringParser
{
public function accepts(string $input): bool;
public function parse(string $input): int;
}
final class InputWithUnits implements TimeStringParser
{
public function accepts(string $input): bool
{
foreach (preg_split('/\s+/', $input) as $chunk) {
if (! preg_match('/^\d+(d|h|m|s)$/', $chunk)) {
return false;
}
}
return true;
}
public function parse(string $input): int
{
if (! $this->accepts($input)) {
throw new \InvalidArgumentException('Invalid input.');
}
$result = 0;
if (preg_match_all('/((?<value>\d+)(?<unit>d|h|m|s))/', $input, $matches)) {
foreach ($matches['unit'] as $i => $unit) {
$value = (int) $matches['value'][$i];
switch ($unit) {
case 'd': $result += $value * 86400; break;
case 'h': $result += $value * 3600; break;
case 'm': $result += $value * 60; break;
case 's': $result += $value * 1; break;
}
}
}
return $result;
}
}
final class InputWithoutUnits implements TimeStringParser
{
public function accepts(string $input): bool
{
foreach (explode(':', $input) as $chunk) {
if (! preg_match('/^\d+$/', trim($chunk))) {
return false;
}
}
return true;
}
public function parse(string $input): int
{
if (! $this->accepts($input)) {
throw new \InvalidArgumentException('Invalid input.');
}
$multiplier = [1, 60, 3600, 86400];
$result = 0;
foreach (array_reverse(explode(':', $input)) as $chunk) {
$value = (int) trim($chunk);
$result += $value * array_shift($multiplier);
}
return $result;
}
}
final class ParserComposite implements TimeStringParser
{
private $parsers;
public function __construct(TimeStringParser ...$parsers)
{
$this->parsers = $parsers;
}
public function accepts(string $input): bool
{
foreach ($this->parsers as $parser) {
if ($parser->accepts($input)) {
return true;
}
}
return false;
}
public function parse(string $input): int
{
foreach ($this->parsers as $parser) {
if ($parser->accepts($input)) {
return $parser->parse($input);
}
}
throw new \InvalidArgumentException('Invalid input.');
}
}
$parser = new ParserComposite(
new InputWithUnits(),
new InputWithoutUnits()
);
$testCases = [
'5d 4h 3m 2s',
'4h 2s',
'3m',
'05: 04: 03: 02',
'4:03:02',
'05: 00: 03: 02',
'02',
'23m',
'2e-5'
];
foreach ($testCases as $testCase) {
if ($parser->accepts($testCase)) {
printf("%-'.20s: %8d\n", $testCase, $parser->parse($testCase));
}
else {
printf("%-'.20s: unsupported\n", $testCase);
}
}
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