help: auto construct help

And add some more verbosity to the help message.

1 files changed, 144 insertions, 44 deletions

diff --git a/src/apk.c b/src/apk.c
index 64b0adb..25e7b07 100644
--- a/src/apk.c
+++ b/src/apk.c
@@ -4,7 +4,7 @@
  * Copyright (C) 2008 Timo Teräs <timo.teras@iki.fi>
  * All rights reserved.
  *
- * This program is free software; you can redistribute it and/or modify it 
+ * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published
  * by the Free Software Foundation. See http://www.gnu.org/ for details.
  */
@@ -20,12 +20,29 @@
 
 #include "apk_defines.h"
 #include "apk_applet.h"
+#include "apk_blob.h"
 
 const char *apk_root;
 struct apk_repository_url apk_repository_list;
 int apk_verbosity = 1, apk_cwd_fd;
 unsigned int apk_flags = 0;
 
+static struct apk_option generic_options[] = {
+	{ 'h', "help",		"Show generic help or applet specific help" },
+	{ 'p', "root",		"Install packages to DIR",
+	  required_argument, "DIR" },
+	{ 'X', "repository",	"Use packages from REPO",
+	  required_argument, "REPO" },
+	{ 'q', "quiet",		"Print less information" },
+	{ 'v', "verbose",	"Print more information" },
+	{ 'V', "version",	"Print program version and exit" },
+	{ 'f', "force",		"Do what was asked even if it looks dangerous" },
+	{ 0x101, "progress",	"Show a progress bar" },
+	{ 0x102, "clean-protected",
+		 "Do not create .apk-new files to configuration dirs" },
+	{ 0x104, "simulate",	"Show what would be done without actually doing it" },
+};
+
 void apk_log(const char *prefix, const char *format, ...)
 {
 	va_list va;
@@ -38,34 +55,116 @@ void apk_log(const char *prefix, const char *format, ...)
 	fprintf(stderr, "\n");
 }
 
-int version(void)
+static int version(void)
 {
 	printf("apk-tools " APK_VERSION "\n");
 	return 0;
 }
 
-int generic_usage(void)
+struct apk_indent {
+	int x;
+	int indent;
+};
+
+static int print_indented(struct apk_indent *i, apk_blob_t blob)
 {
-	struct apk_applet **a;
-	printf("usage: apk COMMAND [-h|--help] [-p|--root DIR] [-X|--repository REPO]\n"
-	       "\t\t   [-q|--quiet] [-v|--verbose] [-V|--version] [-f|--force]\n"
-	       "\t\t   [--progress] [--clean-protected] [--simulate] [ARGS]...\n\n"
-	       "commands: ");
+	static const int wrap_length = 80;
 
-	for (a = &__start_apkapplets; a < &__stop_apkapplets; a++) {
-		printf("%s ",
-		       (*a)->name);
+	if (i->x + blob.len + 1 >= wrap_length) {
+		i->x = i->indent;
+		printf("\n%*s", i->indent - 1, "");
 	}
-	printf("\n\n");
-	return 1;
+	i->x += printf(" %.*s", blob.len, blob.ptr);
+	return 0;
+}
+
+static void print_indented_words(struct apk_indent *i, const char *text)
+{
+	apk_blob_for_each_segment(APK_BLOB_STR(text), " ",
+		(apk_blob_cb) print_indented, i);
 }
 
-int usage(struct apk_applet *applet)
+static int format_option(char *buf, size_t len, struct apk_option *o,
+			 const char *separator)
 {
+	int i = 0;
+
+	if (o->val <= 0xff && isalnum(o->val)) {
+		i += snprintf(&buf[i], len - i, "-%c", o->val);
+		if (o->name != NULL)
+			i += snprintf(&buf[i], len - i, "%s", separator);
+	}
+	if (o->name != NULL)
+		i += snprintf(&buf[i], len - i, "--%s", o->name);
+	if (o->arg_name != NULL)
+		i += snprintf(&buf[i], len - i, " %s", o->arg_name);
+
+	return i;
+}
+
+static void print_usage(const char *cmd, const char *args, int num_opts,
+		        struct apk_option *opts)
+{
+	struct apk_indent indent = { 0, 11 };
+	char word[128];
+	int i, j;
+
+	indent.x = printf("\nusage: apk %s", cmd) - 1;
+	for (i = 0; i < num_opts; i++) {
+		j = 0;
+		word[j++] = '[';
+		j += format_option(&word[j], sizeof(word) - j, &opts[i], "|");
+		word[j++] = ']';
+		print_indented(&indent, APK_BLOB_PTR_LEN(word, j));
+	}
+	if (args != NULL)
+		print_indented(&indent, APK_BLOB_STR(args));
+	printf("\n");
+}
+
+static void print_options(int num_opts, struct apk_option *opts)
+{
+	struct apk_indent indent = { 0, 26 };
+	char word[128];
+	int i;
+
+	for (i = 0; i < num_opts; i++) {
+		format_option(word, sizeof(word), &opts[i], ", ");
+		indent.x = printf("  %-*s", indent.indent - 3, word);
+		print_indented_words(&indent, opts[i].help);
+		printf("\n");
+	}
+}
+
+static int usage(struct apk_applet *applet)
+{
+	struct apk_indent indent = { 0, 2 };
+
 	version();
-	if (applet == NULL)
-		return generic_usage();
-	printf("usage: apk %s %s\n\n", applet->name, applet->usage);
+	if (applet == NULL) {
+		struct apk_applet **a;
+
+		print_usage("COMMAND", "[ARGS]...",
+			    ARRAY_SIZE(generic_options), generic_options);
+
+		printf("\navailable commands:\n  ");
+		for (a = &__start_apkapplets; a < &__stop_apkapplets; a++)
+			printf("%s ", (*a)->name);
+	} else {
+		print_usage(applet->name, applet->arguments,
+			    applet->num_options, applet->options);
+		printf("\ndescription:\n%*s", indent.indent - 1, "");
+		print_indented_words(&indent, applet->help);
+	}
+	printf("\n\ngeneric options:\n");
+	print_options(ARRAY_SIZE(generic_options), generic_options);
+
+	if (applet != NULL && applet->num_options > 0) {
+		printf("\noptions for %s command:\n", applet->name);
+		print_options(applet->num_options, applet->options);
+	}
+	printf("\nThis apk has coffee making abilities.\n\n");
+
 	return 1;
 }
 
@@ -77,7 +176,7 @@ static struct apk_applet *find_applet(const char *name)
 		if (strcmp(name, (*a)->name) == 0)
 			return *a;
 	}
-	
+
 	return NULL;
 }
 
@@ -110,7 +209,7 @@ static struct apk_applet *deduce_applet(int argc, char **argv)
 
 static struct apk_repository_url *apk_repository_new(const char *url)
 {
-	struct apk_repository_url *r = calloc(1, 
+	struct apk_repository_url *r = calloc(1,
 			sizeof(struct apk_repository_url));
 	if (r) {
 		r->url = url;
@@ -119,26 +218,25 @@ static struct apk_repository_url *apk_repository_new(const char *url)
 	return r;
 }
 
-#define NUM_GENERIC_OPTS 10
-static struct option generic_options[32] = {
-	{ "help",		no_argument,		NULL, 'h'},
-	{ "root",		required_argument,	NULL, 'p' },
-	{ "repository",		required_argument,	NULL, 'X' },
-	{ "quiet",		no_argument,		NULL, 'q' },
-	{ "verbose",		no_argument,		NULL, 'v' },
-	{ "version",		no_argument,		NULL, 'V' },
-	{ "force",		no_argument,		NULL, 'f' },
-	{ "progress",		no_argument,		NULL, 0x101 },
-	{ "clean-protected",	no_argument,		NULL, 0x102 },
-	{ "simulate",		no_argument,		NULL, 0x104 },
-};
+static void merge_options(struct option *opts, struct apk_option *ao, int num)
+{
+	int i;
+
+	for (i = 0; i < num; i++, opts++, ao++) {
+		opts->name = ao->name;
+		opts->has_arg = ao->has_arg;
+		opts->flag = NULL;
+		opts->val = ao->val;
+	}
+	opts->name = NULL;
+}
 
 int main(int argc, char **argv)
 {
 	struct apk_applet *applet;
 	char short_options[256], *sopt;
-	struct option *opt;
-	int r, optindex;
+	struct option *opt, *all_options;
+	int r, optindex, num_options;
 	void *ctx = NULL;
 	struct apk_repository_url *repo = NULL;
 
@@ -148,19 +246,20 @@ int main(int argc, char **argv)
 	list_init(&apk_repository_list.list);
 
 	applet = deduce_applet(argc, argv);
+	num_options = ARRAY_SIZE(generic_options) + 1;
+	if (applet != NULL)
+		num_options += applet->num_options;
+	all_options = alloca(sizeof(struct option) * num_options);
+	merge_options(&all_options[0], generic_options,
+	              ARRAY_SIZE(generic_options));
 	if (applet != NULL) {
-		if (applet->num_options && applet->options) {
-			memcpy(&generic_options[NUM_GENERIC_OPTS],
-			       applet->options,
-			       applet->num_options * sizeof(struct option));
-		}
-
+		merge_options(&all_options[ARRAY_SIZE(generic_options)],
+			      applet->options, applet->num_options);
 		if (applet->context_size != 0)
 			ctx = calloc(1, applet->context_size);
 	}
 
-	for (opt = &generic_options[0], sopt = short_options;
-	     opt->name != NULL; opt++) {
+	for (opt = all_options, sopt = short_options; opt->name != NULL; opt++) {
 		if (opt->flag == NULL &&
 		    opt->val <= 0xff && isalnum(opt->val)) {
 			*(sopt++) = opt->val;
@@ -171,7 +270,7 @@ int main(int argc, char **argv)
 
 	optindex = 0;
 	while ((r = getopt_long(argc, argv, short_options,
-				generic_options, &optindex)) != -1) {
+				all_options, &optindex)) != -1) {
 		switch (r) {
 		case 0:
 			break;
@@ -208,7 +307,8 @@ int main(int argc, char **argv)
 			break;
 		default:
 			if (applet == NULL || applet->parse == NULL ||
-			    applet->parse(ctx, r, optindex - NUM_GENERIC_OPTS,
+			    applet->parse(ctx, r,
+					  optindex - ARRAY_SIZE(generic_options),
 					  optarg) != 0)
 				return usage(applet);
 			break;