Allow specifying resource in posix_getrlimit() for single result

Closes GH-9790

Author: iluuu1994

UPGRADING

@@ -23,6 +23,10 @@ PHP 8.3 UPGRADE NOTES
 2. New Features
 ========================================
 
+- Posix
+  . posix_getrlimit() now takes an optional $res parameter to allow fetching a
+    single resource limit.
+
 ========================================
 3. Changes in SAPI modules
 ========================================

ext/posix/posix.c

@@ -1056,16 +1056,43 @@ static const struct limitlist {
 PHP_FUNCTION(posix_getrlimit)
 {
 	const struct limitlist *l = NULL;
+	zend_long res;
+	bool res_is_null = true;
 
-	ZEND_PARSE_PARAMETERS_NONE();
+	ZEND_PARSE_PARAMETERS_START(0, 1)
+		Z_PARAM_OPTIONAL
+		Z_PARAM_LONG_OR_NULL(res, res_is_null)
+	ZEND_PARSE_PARAMETERS_END();
 
-	array_init(return_value);
+	if (res_is_null) {
+		array_init(return_value);
 
-	for (l=limits; l->name; l++) {
-		if (posix_addlimit(l->limit, l->name, return_value) == FAILURE) {
-			zend_array_destroy(Z_ARR_P(return_value));
+		for (l=limits; l->name; l++) {
+			if (posix_addlimit(l->limit, l->name, return_value) == FAILURE) {
+				zend_array_destroy(Z_ARR_P(return_value));
+				RETURN_FALSE;
+			}
+		}
+	} else {
+		struct rlimit rl;
+		int result = getrlimit(res, &rl);
+		if (result < 0) {
+			POSIX_G(last_error) = errno;
 			RETURN_FALSE;
 		}
+
+		array_init(return_value);
+		if (rl.rlim_cur == RLIM_INFINITY) {
+			add_next_index_stringl(return_value, UNLIMITED_STRING, sizeof(UNLIMITED_STRING)-1);
+		} else {
+			add_next_index_long(return_value, rl.rlim_cur);
+		}
+
+		if (rl.rlim_max == RLIM_INFINITY) {
+			add_next_index_stringl(return_value, UNLIMITED_STRING, sizeof(UNLIMITED_STRING)-1);
+		} else {
+			add_next_index_long(return_value, rl.rlim_max);
+		}
 	}
 }
 /* }}} */

ext/posix/posix.stub.php

@@ -338,7 +338,7 @@ function posix_getpwuid(int $user_id): array|false {}
  * @return array<string, int|string>|false
  * @refcount 1
  */
-function posix_getrlimit(): array|false {}
+function posix_getrlimit(?int $resource = null): array|false {}
 #endif
 
 #ifdef HAVE_SETRLIMIT

ext/posix/posix_arginfo.h

@@ -0,0 +1,28 @@
+--TEST--
+posix_getrlimit() for single resource
+--EXTENSIONS--
+posix
+--SKIPIF--
+<?php
+if (!function_exists('posix_getrlimit')) die('skip posix_getrlimit() not found');
+if (!function_exists('posix_setrlimit') || !posix_setrlimit(POSIX_RLIMIT_CORE, 2048, -1)) {
+    die('skip Failed to set POSIX_RLIMIT_CORE');
+}
+?>
+--FILE--
+<?php
+
+posix_setrlimit(POSIX_RLIMIT_CORE, 2048, -1);
+[$hard, $soft] = posix_getrlimit(POSIX_RLIMIT_CORE);
+var_dump($hard, $soft);
+
+posix_setrlimit(POSIX_RLIMIT_CORE, 1024, 2048);
+[$hard, $soft] = posix_getrlimit(POSIX_RLIMIT_CORE);
+var_dump($hard, $soft);
+
+?>
+--EXPECT--
+int(2048)
+string(9) "unlimited"
+int(1024)
+int(2048)