Added a functional version of getopt() and getopt_long(), ready for use

in our commands.

src/core/getopt.c

@@ -0,0 +1,280 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <vsprintf.h>
+#include <getopt.h>
+
+/** @file
+ *
+ * Parse command-line options
+ *
+ */
+
+/**
+ * Option argument
+ *
+ * This will point to the argument for the most recently returned
+ * option, if applicable.
+ */
+char *optarg;
+
+/**
+ * Current option index
+ *
+ * This is an index into the argv[] array.  When getopt() returns -1,
+ * @c optind is the index to the first element that is not an option.
+ */
+int optind = 1;
+
+/**
+ * Current option character index
+ *
+ * This is an index into the current element of argv[].
+ */
+static int nextchar = 0;
+
+/**
+ * Unrecognised option
+ *
+ * When an unrecognised option is encountered, the actual option
+ * character is stored in @c optopt.
+ */
+int optopt;
+
+/**
+ * Reset getopt() internal state
+ *
+ * Due to a limitation of the POSIX getopt() API, it is necessary to
+ * add a call to reset_getopt() before each set of calls to getopt()
+ * or getopt_long().  This arises because POSIX assumes that each
+ * process will parse command line arguments no more than once; this
+ * assumption is not valid within Etherboot.  We work around the
+ * limitation by arranging for execv() to call reset_getopt() before
+ * executing the command.
+ */
+void reset_getopt ( void ) {
+	optind = 1;
+	nextchar = 0;
+}
+
+/**
+ * Get option argument from argv[] array
+ *
+ * @v argc		Argument count
+ * @v argv		Argument list
+ * @ret argument	Option argument, or NULL
+ *
+ * Grab the next element of argv[], if it exists and is not an option.
+ */
+static const char * get_argv_argument ( int argc, char * const argv[] ) {
+	char *arg;
+
+	/* Don't overrun argv[] */
+	if ( optind >= argc )
+		return NULL;
+	arg = argv[optind];
+
+	/* If next argv element is an option, then it's not usable as
+	 * an argument.
+	 */
+	if ( *arg == '-' )
+		return NULL;
+
+	/** Consume this argv element, and return it */
+	optind++;
+	return arg;
+}
+
+/**
+ * Match long option
+ *
+ * @v argc		Argument count
+ * @v argv		Argument list
+ * @v opttext		Option text within current argv[] element
+ * @v longopt		Long option specification
+ * @ret option		Option to return from getopt()
+ * @ret matched		Found a match for this long option
+ */
+static int match_long_option ( int argc, char * const argv[],
+			       const char *opttext,
+			       const struct option *longopt, int *option ) {
+	size_t optlen;
+	const char *argument = NULL;
+
+	/* Compare option name */
+	optlen = strlen ( longopt->name );
+	if ( strncmp ( opttext, longopt->name, optlen ) != 0 )
+		return 0;
+
+	/* Check for inline argument */
+	if ( opttext[optlen] == '=' ) {
+		argument = &opttext[ optlen + 1 ];
+	} else if ( opttext[optlen] ) {
+		/* Long option with trailing garbage - no match */
+		return 0;
+	}
+
+	/* Consume this argv element */
+	optind++;
+
+	/* If we want an argument but don't have one yet, try to grab
+	 * the next argv element
+	 */
+	if ( ( longopt->has_arg != no_argument ) && ( ! argument ) )
+		argument = get_argv_argument ( argc, argv );
+
+	/* If we need an argument but don't have one, sulk */
+	if ( ( longopt->has_arg == required_argument ) && ( ! argument ) ) {
+		printf ( "Option \"%s\" requires an argument\n",
+			 longopt->name );
+		*option = ':';
+		return 1;
+	}
+
+	/* If we have an argument where we shouldn't have one, sulk */
+	if ( ( longopt->has_arg == no_argument ) && argument ) {
+		printf ( "Option \"%s\" takes no argument\n", longopt->name );
+		*option = ':';
+		return 1;
+	}
+
+	/* Store values and return success */
+	optarg = ( char * ) argument;
+	if ( longopt->flag ) {
+		*(longopt->flag) = longopt->val;
+		*option = 0;
+	} else {
+		*option = longopt->val;
+	}
+	return 1;
+}
+
+/**
+ * Match short option
+ *
+ * @v argc		Argument count
+ * @v argv		Argument list
+ * @v opttext		Option text within current argv[] element
+ * @v shortopt		Option character from option specification
+ * @ret option		Option to return from getopt()
+ * @ret matched		Found a match for this short option
+ */
+static int match_short_option ( int argc, char * const argv[],
+				const char *opttext, int shortopt,
+				enum getopt_argument_requirement has_arg,
+				int *option ) {
+	const char *argument = NULL;
+
+	/* Compare option character */
+	if ( *opttext != shortopt )
+		return 0;
+
+	/* Consume option character */
+	opttext++;
+	nextchar++;
+	if ( *opttext ) {
+		if ( has_arg != no_argument ) {
+			/* Consume remainder of element as inline argument */
+			argument = opttext;
+			optind++;
+			nextchar = 0;
+		}
+	} else {
+		/* Reached end of argv element */
+		optind++;
+		nextchar = 0;
+	}
+
+	/* If we want an argument but don't have one yet, try to grab
+	 * the next argv element
+	 */
+	if ( ( has_arg != no_argument ) && ( ! argument ) )
+		argument = get_argv_argument ( argc, argv );
+
+	/* If we need an argument but don't have one, sulk */
+	if ( ( has_arg == required_argument ) && ( ! argument ) ) {
+		printf ( "Option \"%c\" requires an argument\n", shortopt );
+		*option = ':';
+		return 1;
+	}
+
+	/* Store values and return success */
+	optarg = ( char * ) argument;
+	*option = shortopt;
+	return 1;
+}
+
+/**
+ * Parse command-line options
+ *
+ * @v argc		Argument count
+ * @v argv		Argument list
+ * @v optstring		Option specification string
+ * @v longopts		Long option specification table
+ * @ret longindex	Index of long option (or NULL)
+ * @ret option		Option found, or -1 for no more options
+ *
+ */
+int getopt_long ( int argc, char * const argv[], const char *optstring,
+		  const struct option *longopts, int *longindex ) {
+	const char *opttext = argv[optind];
+	const struct option *longopt;
+	int shortopt;
+	enum getopt_argument_requirement has_arg;
+	int option;
+
+	/* Check for end of options */
+	if ( *(opttext++) != '-' )
+		return -1;
+
+	/* Check for long options */
+	if ( *(opttext++) == '-' ) {
+		for ( longopt = longopts ; longopt->name ; longopt++ ) {
+			if ( ! match_long_option ( argc, argv, opttext,
+						   longopt, &option ) )
+				continue;
+			if ( longindex )
+				*longindex = ( longopt - longopts );
+			return option;
+		}
+		optopt = '?';
+		printf ( "Unrecognised option \"--%s\"\n", opttext );
+		return '?';
+	}
+
+	/* Check for short options */
+	if ( nextchar < 1 )
+		nextchar = 1;
+	opttext = ( argv[optind] + nextchar );
+	while ( ( shortopt = *(optstring++) ) ) {
+		has_arg = no_argument;
+		while ( *optstring == ':' ) {
+			has_arg++;
+			optstring++;
+		}
+		if ( match_short_option ( argc, argv, opttext, shortopt,
+					  has_arg, &option ) ) {
+			return option;
+		}
+	}
+	optopt = *opttext;
+	printf ( "Unrecognised option \"-%c\"\n", optopt );
+	return '?';
+}

src/include/getopt.h

@@ -0,0 +1,75 @@
+#ifndef _GETOPT_H
+#define _GETOPT_H
+
+/** @file
+ *
+ * Parse command-line options
+ *
+ */
+
+#include <stddef.h>
+
+enum getopt_argument_requirement {
+	/** Option does not take an argument */
+	no_argument = 0,
+	/** Option requires an argument */
+	required_argument = 1,
+	/** Option may have an argument */
+	optional_argument = 2,
+};
+
+/** A long option, as used for getopt_long() */
+struct option {
+	/** Long name of this option */
+	const char *name;
+	/** Option takes an argument
+	 *
+	 * Must be one of @c no_argument, @c required_argument, or @c
+	 * optional_argument.
+	 */
+	int has_arg;
+	/** Location into which to store @c val, or NULL.
+	 *
+	 * See the description for @c val for more details.
+	 */
+	int *flag;
+	/** Value to return
+	 *
+	 * If @c flag is NULL, then this is the value that will be
+	 * returned by getopt_long() when this option is found, and
+	 * should therefore be set to the equivalent short option
+	 * character.
+	 *
+	 * If @c flag is non-NULL, then this value will be written to
+	 * the location pointed to by @flag, and getopt_long() will
+	 * return 0.
+	 */
+	int val;
+};
+
+extern char *optarg;
+extern int optind;
+extern int optopt;
+
+extern int getopt_long ( int argc, char * const argv[], const char *optstring,
+			 const struct option *longopts, int *longindex );
+
+/**
+ * Parse command-line options
+ *
+ * @v argv		Argument count
+ * @v argv		Argument list
+ * @v optstring		Option specification string
+ * @ret option		Option found, or -1 for no more options
+ *
+ * See getopt_long() for full details.
+ */
+static inline int getopt ( int argc, char * const argv[],
+			   const char *optstring ) {
+	static const struct option no_options[] = {
+		{ NULL, 0, NULL, 0 }
+	};
+	return getopt_long ( argc, argv, optstring, no_options, NULL );
+}
+
+#endif /* _GETOPT_H */