Re: [PATCH 2/4] Mostly the copied code from perf for argument processing

[David Ahern <dsahern@gmail.com>]

On 04/07/11 13:47, Prasad Joshi wrote:
> - parse-options.[ch] has argument processing code.
> 
> - types.h: Additional types for argument processing.
> 
> - strbuf.[ch]: Added a function prefixcmp to compare string prefix

Rather than copy perf code, how about a tools/lib?

David

> 
> Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
> ---
>  tools/kvm/include/kvm/parse-options.h |  161 ++++++++++
>  tools/kvm/include/kvm/strbuf.h        |    6 +
>  tools/kvm/include/kvm/util.h          |    8 +
>  tools/kvm/include/linux/types.h       |   12 +
>  tools/kvm/util/parse-options.c        |  560 +++++++++++++++++++++++++++++++++
>  tools/kvm/util/strbuf.c               |   13 +
>  6 files changed, 760 insertions(+), 0 deletions(-)
>  create mode 100644 tools/kvm/include/kvm/parse-options.h
>  create mode 100644 tools/kvm/include/kvm/strbuf.h
>  create mode 100644 tools/kvm/util/parse-options.c
>  create mode 100644 tools/kvm/util/strbuf.c
> 
> diff --git a/tools/kvm/include/kvm/parse-options.h b/tools/kvm/include/kvm/parse-options.h
> new file mode 100644
> index 0000000..b59220d
> --- /dev/null
> +++ b/tools/kvm/include/kvm/parse-options.h
> @@ -0,0 +1,161 @@
> +#ifndef __PARSE_OPTIONS_H__
> +#define __PARSE_OPTIONS_H__
> +
> +enum parse_opt_type {
> +	/* special types */
> +	OPTION_END,
> +	OPTION_ARGUMENT,
> +	OPTION_GROUP,
> +	/* options with no arguments */
> +	OPTION_BIT,
> +	OPTION_BOOLEAN,
> +	OPTION_INCR,
> +	OPTION_SET_UINT,
> +	OPTION_SET_PTR,
> +	/* options with arguments (usually) */
> +	OPTION_STRING,
> +	OPTION_INTEGER,
> +	OPTION_LONG,
> +	OPTION_CALLBACK,
> +	OPTION_U64,
> +	OPTION_UINTEGER,
> +};
> +
> +enum parse_opt_flags {
> +	PARSE_OPT_KEEP_DASHDASH = 1,
> +	PARSE_OPT_STOP_AT_NON_OPTION = 2,
> +	PARSE_OPT_KEEP_ARGV0 = 4,
> +	PARSE_OPT_KEEP_UNKNOWN = 8,
> +	PARSE_OPT_NO_INTERNAL_HELP = 16,
> +};
> +
> +enum parse_opt_option_flags {
> +	PARSE_OPT_OPTARG  = 1,
> +	PARSE_OPT_NOARG   = 2,
> +	PARSE_OPT_NONEG   = 4,
> +	PARSE_OPT_HIDDEN  = 8,
> +	PARSE_OPT_LASTARG_DEFAULT = 16,
> +};
> +
> +struct option;
> +typedef int parse_opt_cb(const struct option *, const char *arg, int unset);
> +/*
> + * `type`::
> + *   holds the type of the option, you must have an OPTION_END last in your
> + *   array.
> + *
> + * `short_name`::
> + *   the character to use as a short option name, '\0' if none.
> + *
> + * `long_name`::
> + *   the long option name, without the leading dashes, NULL if none.
> + *
> + * `value`::
> + *   stores pointers to the values to be filled.
> + *
> + * `argh`::
> + *   token to explain the kind of argument this option wants. Keep it
> + *   homogenous across the repository.
> + *
> + * `help`::
> + *   the short help associated to what the option does.
> + *   Must never be NULL (except for OPTION_END).
> + *   OPTION_GROUP uses this pointer to store the group header.
> + *
> + * `flags`::
> + *   mask of parse_opt_option_flags.
> + *   PARSE_OPT_OPTARG: says that the argument is optionnal (not for BOOLEANs)
> + *   PARSE_OPT_NOARG: says that this option takes no argument, for CALLBACKs
> + *   PARSE_OPT_NONEG: says that this option cannot be negated
> + *   PARSE_OPT_HIDDEN this option is skipped in the default usage, showed in
> + *                    the long one.
> + *
> + * `callback`::
> + *   pointer to the callback to use for OPTION_CALLBACK.
> + *
> + * `defval`::
> + *   default value to fill (*->value) with for PARSE_OPT_OPTARG.
> + *   OPTION_{BIT,SET_UINT,SET_PTR} store the {mask,integer,pointer} to put in
> + *   the value when met.
> + *   CALLBACKS can use it like they want.
> + */
> +struct option {
> +enum parse_opt_type type;
> +int short_name;
> +const char *long_name;
> +void *value;
> +const char *argh;
> +const char *help;
> +
> +int flags;
> +parse_opt_cb *callback;
> +intptr_t defval;
> +};
> +
> +#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
> +#define check_vtype(v, type) \
> +	(BUILD_BUG_ON_ZERO(!__builtin_types_compatible_p(typeof(v), type)) + v)
> +
> +#define OPT_INTEGER(s, l, v, h)             \
> +{                                           \
> +	.type = OPTION_INTEGER,             \
> +	.short_name = (s),                  \
> +	.long_name = (l),                   \
> +	.value = check_vtype(v, int *),     \
> +	.help = (h)                         \
> +}
> +
> +#define OPT_U64(s, l, v, h)                 \
> +{                                           \
> +	.type = OPTION_U64,                 \
> +	.short_name = (s),                  \
> +	.long_name = (l),                   \
> +	.value = check_vtype(v, u64 *),     \
> +	.help = (h)                         \
> +}
> +
> +#define OPT_STRING(s, l, v, a, h)           \
> +{                                           \
> +	.type = OPTION_STRING,              \
> +	.short_name = (s),                  \
> +	.long_name = (l),                   \
> +	.value = check_vtype(v, const char **), (a), \
> +	.help = (h)                         \
> +}
> +
> +#define OPT_BOOLEAN(s, l, v, h)             \
> +{                                           \
> +	.type = OPTION_BOOLEAN,             \
> +	.short_name = (s),                  \
> +	.long_name = (l),                   \
> +	.value = check_vtype(v, bool *),    \
> +	.help = (h)                         \
> +}
> +
> +#define OPT_END() { .type = OPTION_END }
> +
> +enum {
> +	PARSE_OPT_HELP = -1,
> +	PARSE_OPT_DONE,
> +	PARSE_OPT_UNKNOWN,
> +};
> +
> +/*
> + * It's okay for the caller to consume argv/argc in the usual way.
> + * Other fields of that structure are private to parse-options and should not
> + * be modified in any way.
> + **/
> +struct parse_opt_ctx_t {
> +	const char **argv;
> +	const char **out;
> +	int argc, cpidx;
> +	const char *opt;
> +	int flags;
> +};
> +
> +/* global functions */
> +void usage_with_options(const char * const *usagestr,
> +		const struct option *opts);
> +int parse_options(int argc, const char **argv, const struct option *options,
> +		const char * const usagestr[], int flags);
> +#endif
> diff --git a/tools/kvm/include/kvm/strbuf.h b/tools/kvm/include/kvm/strbuf.h
> new file mode 100644
> index 0000000..e67ca20
> --- /dev/null
> +++ b/tools/kvm/include/kvm/strbuf.h
> @@ -0,0 +1,6 @@
> +#ifndef __STRBUF_H__
> +#define __STRBUF_H__
> +
> +int prefixcmp(const char *str, const char *prefix);
> +
> +#endif
> diff --git a/tools/kvm/include/kvm/util.h b/tools/kvm/include/kvm/util.h
> index 8c80777..ae033cc 100644
> --- a/tools/kvm/include/kvm/util.h
> +++ b/tools/kvm/include/kvm/util.h
> @@ -48,4 +48,12 @@ do {								\
>  
>  extern size_t strlcat(char *dest, const char *src, size_t count);
>  
> +/* some inline functions */
> +
> +static inline const char *skip_prefix(const char *str, const char *prefix)
> +{
> +	size_t len = strlen(prefix);
> +	return strncmp(str, prefix, len) ? NULL : str + len;
> +}
> +
>  #endif /* KVM__UTIL_H */
> diff --git a/tools/kvm/include/linux/types.h b/tools/kvm/include/linux/types.h
> index 70e2546..b989d2a 100644
> --- a/tools/kvm/include/linux/types.h
> +++ b/tools/kvm/include/linux/types.h
> @@ -15,4 +15,16 @@
>  #define __s64		int64_t
>  #define __u64		uint64_t
>  
> +typedef __u64 u64;
> +typedef __s64 s64;
> +
> +typedef __u32 u32;
> +typedef __s32 s32;
> +
> +typedef __u16 u16;
> +typedef __s16 s16;
> +
> +typedef __u8  u8;
> +typedef __s8  s8;
> +
>  #endif /* LINUX_TYPES_H */
> diff --git a/tools/kvm/util/parse-options.c b/tools/kvm/util/parse-options.c
> new file mode 100644
> index 0000000..3065c50
> --- /dev/null
> +++ b/tools/kvm/util/parse-options.c
> @@ -0,0 +1,560 @@
> +#include <stdio.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <stdint.h>
> +
> +#include <stdbool.h>
> +
> +/* user defined includes */
> +#include <linux/types.h>
> +#include <kvm/util.h>
> +#include <kvm/parse-options.h>
> +#include <kvm/strbuf.h>
> +
> +#define OPT_SHORT 1
> +#define OPT_UNSET 2
> +
> +static int opterror(const struct option *opt, const char *reason, int flags)
> +{
> +	if (flags & OPT_SHORT)
> +		return error("switch `%c' %s", opt->short_name, reason);
> +	if (flags & OPT_UNSET)
> +		return error("option `no-%s' %s", opt->long_name, reason);
> +	return error("option `%s' %s", opt->long_name, reason);
> +}
> +
> +static int get_arg(struct parse_opt_ctx_t *p, const struct option *opt,
> +		int flags, const char **arg)
> +{
> +	if (p->opt) {
> +		*arg = p->opt;
> +		p->opt = NULL;
> +	} else if ((opt->flags & PARSE_OPT_LASTARG_DEFAULT) && (p->argc == 1 ||
> +				**(p->argv + 1) == '-')) {
> +		*arg = (const char *)opt->defval;
> +	} else if (p->argc > 1) {
> +		p->argc--;
> +		*arg = *++p->argv;
> +	} else
> +		return opterror(opt, "requires a value", flags);
> +	return 0;
> +}
> +
> +static int get_value(struct parse_opt_ctx_t *p,
> +		const struct option *opt, int flags)
> +{
> +	const char *s, *arg = NULL;
> +	const int unset = flags & OPT_UNSET;
> +
> +	if (unset && p->opt)
> +		return opterror(opt, "takes no value", flags);
> +	if (unset && (opt->flags & PARSE_OPT_NONEG))
> +		return opterror(opt, "isn't available", flags);
> +
> +	if (!(flags & OPT_SHORT) && p->opt) {
> +		switch (opt->type) {
> +		case OPTION_CALLBACK:
> +			if (!(opt->flags & PARSE_OPT_NOARG))
> +				break;
> +		/* FALLTHROUGH */
> +		case OPTION_BOOLEAN:
> +		case OPTION_INCR:
> +		case OPTION_BIT:
> +		case OPTION_SET_UINT:
> +		case OPTION_SET_PTR:
> +			return opterror(opt, "takes no value", flags);
> +		case OPTION_END:
> +		case OPTION_ARGUMENT:
> +		case OPTION_GROUP:
> +		case OPTION_STRING:
> +		case OPTION_INTEGER:
> +		case OPTION_UINTEGER:
> +		case OPTION_LONG:
> +		case OPTION_U64:
> +		default:
> +			break;
> +		}
> +	}
> +
> +	switch (opt->type) {
> +	case OPTION_BIT:
> +		if (unset)
> +			*(int *)opt->value &= ~opt->defval;
> +		else
> +			*(int *)opt->value |= opt->defval;
> +		return 0;
> +
> +	case OPTION_BOOLEAN:
> +		*(bool *)opt->value = unset ? false : true;
> +		return 0;
> +
> +	case OPTION_INCR:
> +		*(int *)opt->value = unset ? 0 : *(int *)opt->value + 1;
> +		return 0;
> +
> +	case OPTION_SET_UINT:
> +		*(unsigned int *)opt->value = unset ? 0 : opt->defval;
> +		return 0;
> +
> +	case OPTION_SET_PTR:
> +		*(void **)opt->value = unset ? NULL : (void *)opt->defval;
> +		return 0;
> +
> +	case OPTION_STRING:
> +		if (unset)
> +			*(const char **)opt->value = NULL;
> +		else if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
> +			*(const char **)opt->value = (const char *)opt->defval;
> +		else
> +			return get_arg(p, opt, flags, (const char **)opt->value);
> +		return 0;
> +
> +	case OPTION_CALLBACK:
> +		if (unset)
> +			return (*opt->callback)(opt, NULL, 1) ? (-1) : 0;
> +		if (opt->flags & PARSE_OPT_NOARG)
> +			return (*opt->callback)(opt, NULL, 0) ? (-1) : 0;
> +		if (opt->flags & PARSE_OPT_OPTARG && !p->opt)
> +			return (*opt->callback)(opt, NULL, 0) ? (-1) : 0;
> +		if (get_arg(p, opt, flags, &arg))
> +			return -1;
> +		return (*opt->callback)(opt, arg, 0) ? (-1) : 0;
> +
> +	case OPTION_INTEGER:
> +		if (unset) {
> +			*(int *)opt->value = 0;
> +			return 0;
> +		}
> +		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
> +			*(int *)opt->value = opt->defval;
> +			return 0;
> +		}
> +		if (get_arg(p, opt, flags, &arg))
> +			return -1;
> +		*(int *)opt->value = strtol(arg, (char **)&s, 10);
> +		if (*s)
> +			return opterror(opt, "expects a numerical value", flags);
> +		return 0;
> +
> +	case OPTION_UINTEGER:
> +		if (unset) {
> +			*(unsigned int *)opt->value = 0;
> +			return 0;
> +		}
> +		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
> +			*(unsigned int *)opt->value = opt->defval;
> +			return 0;
> +		}
> +		if (get_arg(p, opt, flags, &arg))
> +			return -1;
> +		*(unsigned int *)opt->value = strtol(arg, (char **)&s, 10);
> +		if (*s)
> +			return opterror(opt, "expects a numerical value", flags);
> +		return 0;
> +
> +	case OPTION_LONG:
> +		if (unset) {
> +			*(long *)opt->value = 0;
> +			return 0;
> +		}
> +		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
> +			*(long *)opt->value = opt->defval;
> +			return 0;
> +		}
> +		if (get_arg(p, opt, flags, &arg))
> +			return -1;
> +		*(long *)opt->value = strtol(arg, (char **)&s, 10);
> +		if (*s)
> +			return opterror(opt, "expects a numerical value", flags);
> +		return 0;
> +
> +	case OPTION_U64:
> +		if (unset) {
> +			*(u64 *)opt->value = 0;
> +			return 0;
> +		}
> +		if (opt->flags & PARSE_OPT_OPTARG && !p->opt) {
> +			*(u64 *)opt->value = opt->defval;
> +			return 0;
> +		}
> +		if (get_arg(p, opt, flags, &arg))
> +			return -1;
> +		*(u64 *)opt->value = strtoull(arg, (char **)&s, 10);
> +		if (*s)
> +			return opterror(opt, "expects a numerical value", flags);
> +		return 0;
> +
> +	case OPTION_END:
> +	case OPTION_ARGUMENT:
> +	case OPTION_GROUP:
> +	default:
> +		die("should not happen, someone must be hit on the forehead");
> +	}
> +}
> +
> +#define USAGE_OPTS_WIDTH 24
> +#define USAGE_GAP         2
> +
> +static int usage_with_options_internal(const char * const *usagestr,
> +		const struct option *opts, int full)
> +{
> +	if (!usagestr)
> +		return PARSE_OPT_HELP;
> +
> +	fprintf(stderr, "\n usage: %s\n", *usagestr++);
> +	while (*usagestr && **usagestr)
> +		fprintf(stderr, "    or: %s\n", *usagestr++);
> +	while (*usagestr) {
> +		fprintf(stderr, "%s%s\n",
> +				**usagestr ? "    " : "",
> +				*usagestr);
> +		usagestr++;
> +	}
> +
> +	if (opts->type != OPTION_GROUP)
> +		fputc('\n', stderr);
> +
> +	for (; opts->type != OPTION_END; opts++) {
> +		size_t pos;
> +		int pad;
> +
> +		if (opts->type == OPTION_GROUP) {
> +			fputc('\n', stderr);
> +			if (*opts->help)
> +				fprintf(stderr, "%s\n", opts->help);
> +			continue;
> +		}
> +		if (!full && (opts->flags & PARSE_OPT_HIDDEN))
> +			continue;
> +
> +		pos = fprintf(stderr, "    ");
> +		if (opts->short_name)
> +			pos += fprintf(stderr, "-%c", opts->short_name);
> +		else
> +			pos += fprintf(stderr, "    ");
> +
> +		if (opts->long_name && opts->short_name)
> +			pos += fprintf(stderr, ", ");
> +		if (opts->long_name)
> +			pos += fprintf(stderr, "--%s", opts->long_name);
> +
> +		switch (opts->type) {
> +		case OPTION_ARGUMENT:
> +			break;
> +		case OPTION_LONG:
> +		case OPTION_U64:
> +		case OPTION_INTEGER:
> +		case OPTION_UINTEGER:
> +			if (opts->flags & PARSE_OPT_OPTARG)
> +				if (opts->long_name)
> +					pos += fprintf(stderr, "[=<n>]");
> +				else
> +					pos += fprintf(stderr, "[<n>]");
> +			else
> +				pos += fprintf(stderr, " <n>");
> +			break;
> +		case OPTION_CALLBACK:
> +			if (opts->flags & PARSE_OPT_NOARG)
> +				break;
> +		/* FALLTHROUGH */
> +		case OPTION_STRING:
> +			if (opts->argh) {
> +				if (opts->flags & PARSE_OPT_OPTARG)
> +					if (opts->long_name)
> +						pos += fprintf(stderr, "[=<%s>]", opts->argh);
> +					else
> +						pos += fprintf(stderr, "[<%s>]", opts->argh);
> +				else
> +					pos += fprintf(stderr, " <%s>", opts->argh);
> +			} else {
> +				if (opts->flags & PARSE_OPT_OPTARG)
> +					if (opts->long_name)
> +						pos += fprintf(stderr, "[=...]");
> +					else
> +						pos += fprintf(stderr, "[...]");
> +				else
> +					pos += fprintf(stderr, " ...");
> +			}
> +				break;
> +		default: /* OPTION_{BIT,BOOLEAN,SET_UINT,SET_PTR} */
> +		case OPTION_END:
> +		case OPTION_GROUP:
> +		case OPTION_BIT:
> +		case OPTION_BOOLEAN:
> +		case OPTION_INCR:
> +		case OPTION_SET_UINT:
> +		case OPTION_SET_PTR:
> +			break;
> +		}
> +		if (pos <= USAGE_OPTS_WIDTH)
> +			pad = USAGE_OPTS_WIDTH - pos;
> +		else {
> +			fputc('\n', stderr);
> +			pad = USAGE_OPTS_WIDTH;
> +		}
> +		fprintf(stderr, "%*s%s\n", pad + USAGE_GAP, "", opts->help);
> +	}
> +	fputc('\n', stderr);
> +
> +	return PARSE_OPT_HELP;
> +}
> +
> +void usage_with_options(const char * const *usagestr,
> +		const struct option *opts)
> +{
> +	usage_with_options_internal(usagestr, opts, 0);
> +	exit(129);
> +}
> +
> +static void check_typos(const char *arg, const struct option *options)
> +{
> +	if (strlen(arg) < 3)
> +		return;
> +
> +	if (!prefixcmp(arg, "no-")) {
> +		error ("did you mean `--%s` (with two dashes ?)", arg);
> +		exit(129);
> +	}
> +
> +	for (; options->type != OPTION_END; options++) {
> +		if (!options->long_name)
> +			continue;
> +		if (!prefixcmp(options->long_name, arg)) {
> +			error ("did you mean `--%s` (with two dashes ?)", arg);
> +			exit(129);
> +		}
> +	}
> +}
> +
> +static int parse_options_usage(const char * const *usagestr,
> +		const struct option *opts)
> +{
> +	return usage_with_options_internal(usagestr, opts, 0);
> +}
> +
> +static int parse_short_opt(struct parse_opt_ctx_t *p,
> +        const struct option *options)
> +{
> +	for (; options->type != OPTION_END; options++) {
> +		if (options->short_name == *p->opt) {
> +			p->opt = p->opt[1] ? p->opt + 1 : NULL;
> +			return get_value(p, options, OPT_SHORT);
> +		}
> +	}
> +	return -2;
> +}
> +
> +static int parse_long_opt(struct parse_opt_ctx_t *p, const char *arg,
> +		const struct option *options)
> +{
> +	const char *arg_end = strchr(arg, '=');
> +	const struct option *abbrev_option = NULL, *ambiguous_option = NULL;
> +	int abbrev_flags = 0, ambiguous_flags = 0;
> +
> +	if (!arg_end)
> +		arg_end = arg + strlen(arg);
> +
> +	for (; options->type != OPTION_END; options++) {
> +		const char *rest;
> +		int flags = 0;
> +
> +		if (!options->long_name)
> +			continue;
> +
> +		rest = skip_prefix(arg, options->long_name);
> +		if (options->type == OPTION_ARGUMENT) {
> +			if (!rest)
> +				continue;
> +			if (*rest == '=')
> +				return opterror(options, "takes no value", flags);
> +			if (*rest)
> +				continue;
> +			p->out[p->cpidx++] = arg - 2;
> +			return 0;
> +		}
> +		if (!rest) {
> +			/* abbreviated? */
> +			if (!strncmp(options->long_name, arg, arg_end - arg)) {
> +is_abbreviated:
> +				if (abbrev_option) {
> +					/*
> +					 * If this is abbreviated, it is
> +					 * ambiguous. So when there is no
> +					 * exact match later, we need to
> +					 * error out.
> +					 */
> +					ambiguous_option = abbrev_option;
> +					ambiguous_flags = abbrev_flags;
> +				}
> +				if (!(flags & OPT_UNSET) && *arg_end)
> +					p->opt = arg_end + 1;
> +				abbrev_option = options;
> +				abbrev_flags = flags;
> +				continue;
> +			}
> +			/* negated and abbreviated very much? */
> +			if (!prefixcmp("no-", arg)) {
> +				flags |= OPT_UNSET;
> +				goto is_abbreviated;
> +			}
> +			/* negated? */
> +			if (strncmp(arg, "no-", 3))
> +				continue;
> +			flags |= OPT_UNSET;
> +			rest = skip_prefix(arg + 3, options->long_name);
> +			/* abbreviated and negated? */
> +			if (!rest && !prefixcmp(options->long_name, arg + 3))
> +				goto is_abbreviated;
> +			if (!rest)
> +				continue;
> +		}
> +		if (*rest) {
> +			if (*rest != '=')
> +				continue;
> +			p->opt = rest + 1;
> +		}
> +		return get_value(p, options, flags);
> +	}
> +
> +	if (ambiguous_option)
> +		return error("Ambiguous option: %s "
> +				"(could be --%s%s or --%s%s)",
> +				arg,
> +				(ambiguous_flags & OPT_UNSET) ?  "no-" : "",
> +				ambiguous_option->long_name,
> +				(abbrev_flags & OPT_UNSET) ?  "no-" : "",
> +				abbrev_option->long_name);
> +	if (abbrev_option)
> +		return get_value(p, abbrev_option, abbrev_flags);
> +	return -2;
> +}
> +
> +
> +static void parse_options_start(struct parse_opt_ctx_t *ctx, int argc,
> +		const char **argv, int flags)
> +{
> +	memset(ctx, 0, sizeof(*ctx));
> +	ctx->argc = argc;
> +	ctx->argv = argv;
> +	ctx->out  = argv;
> +	ctx->cpidx = ((flags & PARSE_OPT_KEEP_ARGV0) != 0);
> +	ctx->flags = flags;
> +	if ((flags & PARSE_OPT_KEEP_UNKNOWN) &&
> +			(flags & PARSE_OPT_STOP_AT_NON_OPTION))
> +		die("STOP_AT_NON_OPTION and KEEP_UNKNOWN don't go together");
> +}
> +
> +static int parse_options_end(struct parse_opt_ctx_t *ctx)
> +{
> +	memmove(ctx->out + ctx->cpidx, ctx->argv, ctx->argc * sizeof(*ctx->out));
> +	ctx->out[ctx->cpidx + ctx->argc] = NULL;
> +	return ctx->cpidx + ctx->argc;
> +}
> +
> +
> +static int parse_options_step(struct parse_opt_ctx_t *ctx,
> +		const struct option *options, const char * const usagestr[])
> +{
> +	int internal_help = !(ctx->flags & PARSE_OPT_NO_INTERNAL_HELP);
> +
> +	/* we must reset ->opt, unknown short option leave it dangling */
> +	ctx->opt = NULL;
> +
> +	for (; ctx->argc; ctx->argc--, ctx->argv++) {
> +		const char *arg = ctx->argv[0];
> +
> +		if (*arg != '-' || !arg[1]) {
> +			if (ctx->flags & PARSE_OPT_STOP_AT_NON_OPTION)
> +				break;
> +			ctx->out[ctx->cpidx++] = ctx->argv[0];
> +			continue;
> +		}
> +
> +		if (arg[1] != '-') {
> +			ctx->opt = arg + 1;
> +			if (internal_help && *ctx->opt == 'h')
> +				return parse_options_usage(usagestr, options);
> +			switch (parse_short_opt(ctx, options)) {
> +			case -1:
> +				return parse_options_usage(usagestr, options);
> +			case -2:
> +				goto unknown;
> +			default:
> +				break;
> +			}
> +			if (ctx->opt)
> +				check_typos(arg + 1, options);
> +			while (ctx->opt) {
> +				if (internal_help && *ctx->opt == 'h')
> +					return parse_options_usage(usagestr, options);
> +				switch (parse_short_opt(ctx, options)) {
> +				case -1:
> +					return parse_options_usage(usagestr, options);
> +				case -2:
> +					/* fake a short option thing to hide the fact that we may have
> +					 * started to parse aggregated stuff
> +					 *
> +					 * This is leaky, too bad.
> +					 */
> +					ctx->argv[0] = strdup(ctx->opt - 1);
> +					*(char *)ctx->argv[0] = '-';
> +					goto unknown;
> +				default:
> +					break;
> +				}
> +			}
> +			continue;
> +		}
> +
> +		if (!arg[2]) { /* "--" */
> +			if (!(ctx->flags & PARSE_OPT_KEEP_DASHDASH)) {
> +				ctx->argc--;
> +				ctx->argv++;
> +			}
> +			break;
> +		}
> +
> +		if (internal_help && !strcmp(arg + 2, "help-all"))
> +			return usage_with_options_internal(usagestr, options, 1);
> +		if (internal_help && !strcmp(arg + 2, "help"))
> +			return parse_options_usage(usagestr, options);
> +		switch (parse_long_opt(ctx, arg + 2, options)) {
> +		case -1:
> +			return parse_options_usage(usagestr, options);
> +		case -2:
> +			goto unknown;
> +		default:
> +			break;
> +		}
> +		continue;
> +unknown:
> +		if (!(ctx->flags & PARSE_OPT_KEEP_UNKNOWN))
> +			return PARSE_OPT_UNKNOWN;
> +		ctx->out[ctx->cpidx++] = ctx->argv[0];
> +		ctx->opt = NULL;
> +	}
> +	return PARSE_OPT_DONE;
> +}
> +
> +int parse_options(int argc, const char **argv, const struct option *options,
> +		const char * const usagestr[], int flags)
> +{
> +	struct parse_opt_ctx_t ctx;
> +
> +	parse_options_start(&ctx, argc, argv, flags);
> +	switch (parse_options_step(&ctx, options, usagestr)) {
> +	case PARSE_OPT_HELP:
> +		exit(129);
> +	case PARSE_OPT_DONE:
> +		break;
> +	default: /* PARSE_OPT_UNKNOWN */
> +		if (ctx.argv[0][1] == '-') {
> +			error("unknown option `%s'", ctx.argv[0] + 2);
> +		} else {
> +			error("unknown switch `%c'", *ctx.opt);
> +		}
> +		usage_with_options(usagestr, options);
> +	}
> +
> +	return parse_options_end(&ctx);
> +}
> diff --git a/tools/kvm/util/strbuf.c b/tools/kvm/util/strbuf.c
> new file mode 100644
> index 0000000..ec77ab1
> --- /dev/null
> +++ b/tools/kvm/util/strbuf.c
> @@ -0,0 +1,13 @@
> +
> +/* user defined headers */
> +#include <kvm/strbuf.h>
> +
> +int prefixcmp(const char *str, const char *prefix)
> +{
> +	for (; ; str++, prefix++) {
> +		if (!*prefix)
> +			return 0;
> +		else if (*str != *prefix)
> +			return (unsigned char)*prefix - (unsigned char)*str;
> +	}
> +}