LibC: Implement getopt_long{,_only}

Few ports attempt to use this so lets add them :D

userspace/libraries/LibC/CMakeLists.txt

@@ -12,6 +12,7 @@ set(LIBC_SOURCES
 	fenv.cpp
 	fnmatch.cpp
 	ftw.cpp
+	getopt.cpp
 	grp.cpp
 	ifaddrs.cpp
 	inttypes.cpp

userspace/libraries/LibC/getopt.cpp

@@ -0,0 +1,194 @@
+#include <assert.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <string.h>
+
+char* optarg = nullptr;
+int opterr = 1;
+int optind = 1;
+int optopt = 0;
+
+static int s_idx_in_arg = -1;
+static int s_old_optind = 1;
+
+static int getopt_long_impl(int argc, char* const argv[], const char* optstring, const struct option* longopts, int* longindex, bool need_double_hyphen)
+{
+	if (optind >= argc)
+		return -1;
+
+	if (optind == 0)
+	{
+		s_old_optind = -1;
+		s_idx_in_arg = -1;
+		optind = 1;
+	}
+
+	const char* curr = argv[optind];
+	if (curr == nullptr || curr[0] != '-' || curr[1] == '\0')
+		return -1;
+
+	if (curr[1] == '-' && curr[2] == '\0')
+	{
+		optind++;
+		return -1;
+	}
+
+	if (s_old_optind != optind)
+		s_idx_in_arg = -1;
+	struct dummy { ~dummy() { s_old_optind = optind; }} _;
+
+	if (s_idx_in_arg == -1 && (!need_double_hyphen || curr[1] == '-'))
+	{
+		for (size_t i = 0; longopts[i].name; i++)
+		{
+			const auto& opt = longopts[i];
+			const size_t name_len = strlen(opt.name);
+			if (strncmp(curr + 2, opt.name, name_len) != 0)
+				continue;
+			if (curr[2 + name_len] != '=' && curr[2 + name_len] != '\0')
+				continue;
+
+			bool has_argument;
+			switch (opt.has_arg)
+			{
+				case no_argument:
+					has_argument = false;
+					break;
+				case required_argument:
+					has_argument = true;
+					break;
+				case optional_argument:
+					has_argument = (curr[2 + name_len] == '=')
+						|| (optind + 1 < argc && argv[optind + 1][0] != '-');
+					break;
+				default:
+					assert(false);
+			}
+
+			if (!has_argument)
+			{
+				if (curr[2 + name_len] == '=')
+				{
+					if (opterr && optstring[0] != ':')
+						fprintf(stderr, "%s: option takes no argument -- %.*s\n", argv[0], static_cast<int>(name_len), curr + 2);
+					optind++;
+					return (optstring[0] == ':') ? ':' : '?';
+				}
+				optarg = nullptr;
+				optind++;
+			}
+			else
+			{
+				if (curr[2 + name_len] == '=')
+				{
+					optarg = const_cast<char*>(curr + 2 + name_len + 1);
+					optind++;
+				}
+				else
+				{
+					if (optind + 1 >= argc)
+					{
+						if (opterr && optstring[0] != ':')
+							fprintf(stderr, "%s: option requires an argument -- %.*s\n", argv[0], static_cast<int>(name_len), curr + 2);
+						optind++;
+						return (optstring[0] == ':') ? ':' : '?';
+					}
+					optarg = argv[optind + 1];
+					optind += 2;
+				}
+			}
+
+			if (longindex != nullptr)
+				*longindex = i;
+
+			if (opt.flag == nullptr)
+				return opt.val;
+			*opt.flag = opt.val;
+			return 0;
+		}
+
+		if (curr[1] == '-')
+		{
+			if (opterr && optstring[0] != ':')
+				fprintf(stderr, "%s: illegal option -- %s\n", argv[0], curr + 2);
+			optind++;
+			return '?';
+		}
+	}
+
+	if (s_idx_in_arg == -1)
+		s_idx_in_arg = 1;
+
+	for (size_t i = 0; optstring[i]; i++)
+	{
+		if (optstring[i] == ':')
+			continue;
+		if (curr[s_idx_in_arg] != optstring[i])
+			continue;
+
+		const bool has_argument = (optstring[i + 1] == ':');
+		if (!has_argument)
+		{
+			s_idx_in_arg++;
+			if (curr[s_idx_in_arg] == '\0')
+			{
+				s_idx_in_arg = -1;
+				optind++;
+			}
+		}
+		else
+		{
+			if (curr[s_idx_in_arg + 1] != '\0')
+			{
+				optarg = const_cast<char*>(curr + s_idx_in_arg + 1);
+				optind++;
+				s_idx_in_arg = -1;
+			}
+			else
+			{
+				if (optind + 1 >= argc)
+				{
+					if (opterr && optstring[0] != ':')
+						fprintf(stderr, "%s: option requires an argument -- %c\n", argv[0], optstring[i]);
+					optopt = optstring[i];
+					optind++;
+					return optstring[0] == ':' ? ':' : '?';
+				}
+				optarg = const_cast<char*>(argv[optind + 1]);
+				optind += 2;
+				s_idx_in_arg = -1;
+			}
+		}
+
+		return optstring[i];
+	}
+
+	if (opterr && optstring[0] != ':')
+		fprintf(stderr, "%s: illegal option -- %c\n", argv[0], curr[s_idx_in_arg]);
+	optopt = curr[s_idx_in_arg];
+
+	s_idx_in_arg++;
+	if (curr[s_idx_in_arg] == '\0')
+	{
+		s_idx_in_arg = -1;
+		optind++;
+	}
+
+	return '?';
+}
+
+int getopt(int argc, char* const argv[], const char* optstring)
+{
+	struct option option {};
+	return getopt_long_impl(argc, argv, optstring, &option, nullptr, true);
+}
+
+int getopt_long(int argc, char* argv[], const char* optstring, const struct option* longopts, int* longindex)
+{
+	return getopt_long_impl(argc, argv, optstring, longopts, longindex, true);
+}
+
+int getopt_long_only(int argc, char* argv[], const char* optstring, const struct option* longopts, int* longindex)
+{
+	return getopt_long_impl(argc, argv, optstring, longopts, longindex, false);
+}

userspace/libraries/LibC/include/bits/getopt.h

@@ -0,0 +1,15 @@
+#ifndef _BITS_GETOPT_H
+#define _BITS_GETOPT_H 1
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+int getopt(int argc, char* const argv[], const char* optstring);
+
+extern char* optarg;
+extern int   opterr, optind, optopt;
+
+__END_DECLS
+
+#endif

userspace/libraries/LibC/include/getopt.h

@@ -0,0 +1,27 @@
+#ifndef _GETOPT_H
+#define _GETOPT_H 1
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#include <bits/getopt.h>
+
+struct option
+{
+	const char* name;
+	int has_arg;
+	int* flag;
+	int val;
+};
+
+#define no_argument 0
+#define required_argument 1
+#define optional_argument 2
+
+int getopt_long(int argc, char* argv[], const char* optstring, const struct option* longopts, int* longindex);
+int getopt_long_only(int argc, char* argv[], const char* optstring, const struct option* longopts, int* longindex);
+
+__END_DECLS
+
+#endif

userspace/libraries/LibC/include/unistd.h

@@ -124,6 +124,8 @@ __BEGIN_DECLS
 #define __need_useconds_t
 #include <sys/types.h>
 
+#include <bits/getopt.h>
+
 enum
 {
 	_CS_PATH = 1,
@@ -547,7 +549,6 @@ long				gethostid(void);
 int					gethostname(char* name, size_t namelen);
 char*				getlogin(void);
 int					getlogin_r(char* name, size_t namesize);
-int					getopt(int argc, char* const argv[], const char* optstring);
 pid_t				getpgid(pid_t pid);
 pid_t				getpgrp(void);
 pid_t				getpid(void);
@@ -600,9 +601,6 @@ int					chroot(const char* path);
 int					getpagesize(void);
 char*				getpass(const char* prompt);
 
-extern char*	optarg;
-extern int		opterr, optind, optopt;
-
 long syscall(long syscall, ...);
 
 __END_DECLS

userspace/libraries/LibC/unistd.cpp

@@ -541,91 +541,6 @@ int rmdir(const char* path)
 	return unlinkat(AT_FDCWD, path, AT_REMOVEDIR);
 }
 
-char* optarg = nullptr;
-int opterr = 1;
-int optind = 1;
-int optopt = 0;
-
-int getopt(int argc, char* const argv[], const char* optstring)
-{
-	if (optind >= argc)
-		return -1;
-
-	static int idx = 1;
-	const char* current = argv[optind];
-
-	// if "--" is encountered, no more options are parsed
-	if (idx == -1)
-		return -1;
-
-	// if current is nullptr, does not start with '-' or is string "-", return -1
-	if (current == nullptr || current[0] != '-' || current[1] == '\0')
-		return -1;
-
-	// if current points to string "--" increment optind and return -1
-	if (current[1] == '-' && current[2] == '\0')
-	{
-		idx = -1;
-		optind++;
-		return -1;
-	}
-
-	for (size_t i = 0; optstring[i]; i++)
-	{
-		if (optstring[i] == ':')
-			continue;
-		if (current[idx] != optstring[i])
-			continue;
-
-		if (optstring[i + 1] == ':')
-		{
-			if (current[idx + 1])
-			{
-				optarg = const_cast<char*>(current + idx + 1);
-				optind += 1;
-			}
-			else
-			{
-				optarg = const_cast<char*>(argv[optind + 1]);
-				optind += 2;
-			}
-
-			idx = 1;
-
-			if (optind > argc)
-			{
-				if (opterr && optstring[0] != ':')
-					fprintf(stderr, "%s: option requires an argument -- %c\n", argv[0], optstring[i]);
-				optopt = optstring[i];
-				return optstring[0] == ':' ? ':' : '?';
-			}
-
-			return optstring[i];
-		}
-		else
-		{
-			if (current[++idx] == '\0')
-			{
-				idx = 1;
-				optind++;
-			}
-
-			return optstring[i];
-		}
-	}
-
-	if (opterr && optstring[0] != ':')
-		fprintf(stderr, "%s: illegal option -- %c\n", argv[0], current[idx]);
-
-	if (current[++idx] == '\0')
-	{
-		idx = 1;
-		optind++;
-	}
-
-	return '?';
-}
-
 int chroot(const char* path)
 {
 	return syscall(SYS_CHROOT, path);