Add getopt(3) and getopt_long(3).

libc/Makefile

@@ -220,6 +220,8 @@ fsmarshall/fsm_listen.o \
 fsmarshall/fsm_mkserver.o \
 fsmarshall/fsm_recv.o \
 fsmarshall/fsm_send.o \
+getopt/getopt_long.o \
+getopt/getopt.o \
 grp/grent.o \
 init/init.o \
 libgen/basename.o \

libc/getopt/getopt.cpp

@@ -0,0 +1,31 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    getopt/getopt.cpp
+    Command-line parsing utility function.
+
+*******************************************************************************/
+
+#include <stddef.h>
+#include <getopt.h>
+
+extern "C" int getopt(int argc, char* const* argv, const char* shortopts)
+{
+	return getopt_long(argc, argv, shortopts, NULL, NULL);
+}

libc/getopt/getopt_long.cpp

@@ -0,0 +1,255 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    getopt/getopt_long.cpp
+    Command-line parsing utility function.
+
+*******************************************************************************/
+
+#include <assert.h>
+#include <errno.h>
+#include <error.h>
+#include <getopt.h>
+#include <string.h>
+
+extern "C" { char* optarg = NULL; }
+extern "C" { int opterr = 1; }
+extern "C" { int optind = 1; }
+extern "C" { int optopt = 0; }
+
+static char* const* optcurargv;
+static const char* optcurarg;
+static int optcurind;
+static size_t optcurpos;
+
+static bool optcurvalid = false;
+
+static bool is_supported_option_declaration(const char* shortopts)
+{
+	// Optional parameters to options only make sense after a option character.
+	if ( shortopts[0] == ':' && shortopts[1] == ':' )
+		return false;
+
+	for ( size_t i = 0; shortopts[i]; i++ )
+	{
+		if ( shortopts[i] == '-' || shortopts[i] == '+' || shortopts[i] == ';' )
+			return false;
+
+		// We support a: and a::, but a::: doesn't make sense.
+		if ( shortopts[i] == ':' &&
+		     shortopts[i+1] == ':' &&
+		     shortopts[i+2] == ':' )
+			return false;
+
+		// We don't support that -W foo is the same as --foo.
+		if ( shortopts[i] == 'W' && shortopts[i+1] == ';' )
+			return false;
+	}
+	return true;
+}
+
+// TODO: It would appear that it is allowed to abbreviate options if the
+//       abbreviation isn't ambiguous. (WTF)
+static
+const struct option* find_long_option(char* arg,
+                                      const struct option* longopts,
+                                      int* option_index,
+                                      char** option_arg)
+{
+	char* argname = arg + 2;
+	size_t argname_length = strcspn(arg, "=");
+
+	for ( int i = 0; longopts && longopts[i].name; i++ )
+	{
+		if ( longopts[i].has_arg == no_argument &&
+		     argname[argname_length] == '=' )
+			continue;
+		if ( strncmp(argname, longopts[i].name, argname_length) != 0 )
+			continue;
+		if ( longopts[i].name[argname_length] != '\0' )
+			continue;
+		return *option_arg = (argname[argname_length] == '=' ?
+		                      argname + argname_length + 1 :
+		                      NULL),
+		       *option_index = i,
+		       &longopts[i];
+	}
+	return NULL;
+}
+
+extern "C"
+int getopt_long(int argc, char* const* argv, const char* shortopts,
+                const struct option* longopts, int* longindex)
+{
+	assert(shortopts);
+	assert(0 <= optind);
+
+	// Verify that the input string was compatible.
+	if ( !is_supported_option_declaration(shortopts) )
+		return errno = EINVAL, -1;
+
+	// The caller will handle missing arguments if the short options string
+	// start with a colon character.
+	bool caller_handles_missing_argument = false;
+	if ( shortopts[0] == ':' )
+		shortopts++,
+		caller_handles_missing_argument = false;
+
+	// Check if we have finished processing the command line.
+	if ( argc <= optind )
+		return optcurvalid = false, -1;
+
+	char* arg = argv[optind];
+
+	// Stop if we encountered a NULL pointer.
+	if ( !arg )
+		return optcurvalid = false, -1;
+
+	// Stop if we encounteed an argument that didn't start with -.
+	if ( arg[0] != '-' )
+		return optcurvalid = false, -1;
+
+	// Stop if we encounted the string "-" as an argument.
+	if ( arg[1] == '\0' )
+		return optcurvalid = false, -1;
+
+	// Stop and skip the argument if we encountered the string "--".
+	if ( arg[1] == '-' && arg[2] == '\0' )
+		return optcurvalid = false, optind++, -1;
+
+	// Check if we encountered a long option.
+	if ( arg[1] == '-' && arg[2] != '\0' )
+	{
+		// Locate the long option.
+		int option_index;
+		char* option_arg;
+		const struct option* option =
+			find_long_option(arg, longopts, &option_index, &option_arg);
+
+		// Increment so we don't process the next argument on the next call.
+		optind++;
+
+		// Verify the long option is allowed.
+		if ( !option )
+			return '?';
+
+		// Check whether the next argument is the parameter to this option.
+		if ( !option_arg && option->has_arg != no_argument )
+		{
+			if ( optind + 1 < argc && argv[optind] &&
+			     (option->has_arg == required_argument || argv[optind][0] != '-') )
+				option_arg = argv[optind++];
+		}
+
+		// Return an error if a required option parameter was missing.
+		if ( !option_arg && option->has_arg == required_argument )
+		{
+			if ( caller_handles_missing_argument )
+				return *longindex = option_index, ':';
+			if ( opterr )
+				error(0, 0, "option requires an argument `--%s'", option->name);
+			return '?';
+		}
+
+		return optarg = option_arg,
+		       *longindex = option_index,
+		       option->flag ? (*option->flag = option->val, 0) : option->val;
+	}
+
+	// Unfortunately, there is no standardized optpos global variable, and
+	// programs are supposed to be able to restart the parsing by setting optind
+	// to 1. We need to keep track of the current position in the current
+	// argument, but it would have to be invalidated whenever we restart the
+	// parsing. We keep track of what the parsing input is supposed to be so we
+	// can easily invalidate the current position in the current argument
+	// whenever something fishy is going on.
+	if ( !optcurvalid || optcurargv != argv || optcurarg != arg || optcurind != optind )
+	{
+		optcurargv = argv;
+		optcurarg = arg;
+		optcurind = optind;
+		optcurpos = 1;
+		optcurvalid = true;
+	}
+
+	int short_option = (unsigned char) arg[optcurpos++];
+
+	// The character : can't be a option character.
+	if ( short_option == ':' )
+		short_option = '?';
+
+	// Verify the short option is allowed.
+	char* opt_decl = strchr(shortopts, short_option);
+	if ( !opt_decl )
+	{
+		optopt = short_option;
+		short_option = '?';
+	}
+
+	// Check whether the short option requires an parameter.
+	if ( opt_decl[1] == ':' )
+	{
+		// This argument cannot contain more short options after this.
+		optcurvalid = false;
+
+		// A double :: means optional parameter.
+		bool required = opt_decl[2] != ':';
+
+		// The rest of the argument is the parameter if non-empty.
+		if ( arg[optcurpos] )
+		{
+			optarg = arg + optcurpos;
+			optind += 1;
+		}
+
+		// Otherwise, the next element (if any) is the parameter.
+		else if ( optind + 1 < argc && argv[optind+1] &&
+		          (required || argv[optind+1][0] != '-') )
+		{
+			optarg = argv[optind+1];
+			optind += 2;
+		}
+
+		// It's okay to have a missing parameter if it was optional.
+		else if ( !required )
+		{
+			optarg = NULL;
+			optind += 1;
+		}
+
+		// Return an error if a required option parameter was missing.
+		else
+		{
+			if ( caller_handles_missing_argument )
+				return optopt = short_option, ':';
+			if ( opterr )
+				error(0, 0, "option requires an argument -- '%c'", short_option);
+			return optopt = short_option, '?';
+		}
+	}
+
+	// If we reached the last option, use the next index next time.
+	else if ( !arg[optcurpos] )
+	{
+		optind++;
+		optcurvalid = false;
+	}
+
+	return short_option;
+}

libc/include/getopt.h

@@ -0,0 +1,59 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    getopt.h
+    Command-line parsing facility.
+
+*******************************************************************************/
+
+#ifndef INCLUDE_GETOPT_H
+#define INCLUDE_GETOPT_H
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+/* These declarations are repeated in <unistd.h>. */
+#ifndef __getopt_unistd_shared_declared
+#define __getopt_unistd_shared_declared
+extern char* optarg;
+extern int opterr;
+extern int optind;
+extern int optopt;
+
+int getopt(int, char* const*, const char*);
+#endif
+
+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, char* const*, const char*, const struct option*, int*);
+
+__END_DECLS
+
+#endif

libc/include/unistd.h

@@ -271,7 +271,7 @@ int fexecve(int, char* const [], char* const []);
 long fpathconf(int, int);
 int getgroups(int, gid_t []);
 long gethostid(void);
-int getopt(int, char* const [], const char*);
+
 pid_t getpgrp(void);
 pid_t getsid(pid_t);
 int lockf(int, int, off_t);
@@ -289,9 +289,6 @@ int ttyname_r(int, char*, size_t);
 #if __POSIX_OBSOLETE <= 200801
 pid_t setpgrp(void);
 #endif
-
-extern char* optarg;
-extern int opterr, optind, optopt;
 #endif
 
 int access(const char*, int);
@@ -384,6 +381,20 @@ size_t writeleast(int fd, const void* buf, size_t least, size_t max);
 void* sbrk(__intptr_t increment);
 #endif
 
+/* For compatibility with POSIX, declare getopt(3) here. */
+#if !defined(_SORTIX_SOURCE)
+/* These declarations are repeated in <getopt.h>. */
+#ifndef __getopt_unistd_shared_declared
+#define __getopt_unistd_shared_declared
+extern char* optarg;
+extern int opterr;
+extern int optind;
+extern int optopt;
+
+int getopt(int, char* const*, const char*);
+#endif
+#endif
+
 __END_DECLS
 
 #endif