Merge branch 'baserock/tiagogomes/btrfs2' into baserock/morphbaserock/morph

1 files changed, 214 insertions, 0 deletions

diff --git a/help.c b/help.c
new file mode 100644
index 0000000..6d04293
--- /dev/null
+++ b/help.c
@@ -0,0 +1,214 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "commands.h"
+
+extern char argv0_buf[ARGV0_BUF_SIZE];
+
+#define USAGE_SHORT		1U
+#define USAGE_LONG		2U
+#define USAGE_OPTIONS		4U
+#define USAGE_LISTING		8U
+
+static int do_usage_one_command(const char * const *usagestr,
+				unsigned int flags, FILE *outf)
+{
+	int pad = 4;
+
+	if (!usagestr || !*usagestr)
+		return -1;
+
+	fprintf(outf, "%s%s\n", (flags & USAGE_LISTING) ? "    " : "usage: ",
+		*usagestr++);
+
+	/* a short one-line description (mandatory) */
+	if ((flags & USAGE_SHORT) == 0)
+		return 0;
+	else if (!*usagestr)
+		return -2;
+
+	if (flags & USAGE_LISTING)
+		pad = 8;
+	else
+		fputc('\n', outf);
+
+	fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
+
+	/* a long (possibly multi-line) description (optional) */
+	if (!*usagestr || ((flags & USAGE_LONG) == 0))
+		return 0;
+
+	if (**usagestr)
+		fputc('\n', outf);
+	while (*usagestr && **usagestr)
+		fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
+
+	/* options (optional) */
+	if (!*usagestr || ((flags & USAGE_OPTIONS) == 0))
+		return 0;
+
+	/*
+	 * options (if present) should always (even if there is no long
+	 * description) be prepended with an empty line, skip it
+	 */
+	usagestr++;
+
+	fputc('\n', outf);
+	while (*usagestr)
+		fprintf(outf, "%*s%s\n", pad, "", *usagestr++);
+
+	return 0;
+}
+
+static int usage_command_internal(const char * const *usagestr,
+				  const char *token, int full, int lst,
+				  FILE *outf)
+{
+	unsigned int flags = USAGE_SHORT;
+	int ret;
+
+	if (full)
+		flags |= USAGE_LONG | USAGE_OPTIONS;
+	if (lst)
+		flags |= USAGE_LISTING;
+
+	ret = do_usage_one_command(usagestr, flags, outf);
+	switch (ret) {
+	case -1:
+		fprintf(outf, "No usage for '%s'\n", token);
+		break;
+	case -2:
+		fprintf(outf, "No short description for '%s'\n", token);
+		break;
+	}
+
+	return ret;
+}
+
+static void usage_command_usagestr(const char * const *usagestr,
+				   const char *token, int full, int err)
+{
+	FILE *outf = err ? stderr : stdout;
+	int ret;
+
+	ret = usage_command_internal(usagestr, token, full, 0, outf);
+	if (!ret)
+		fputc('\n', outf);
+}
+
+void usage_command(const struct cmd_struct *cmd, int full, int err)
+{
+	usage_command_usagestr(cmd->usagestr, cmd->token, full, err);
+}
+
+void usage(const char * const *usagestr)
+{
+	usage_command_usagestr(usagestr, NULL, 1, 1);
+	exit(129);
+}
+
+static void usage_command_group_internal(const struct cmd_group *grp, int full,
+					 FILE *outf)
+{
+	const struct cmd_struct *cmd = grp->commands;
+	int do_sep = 0;
+
+	for (; cmd->token; cmd++) {
+		if (cmd->hidden)
+			continue;
+
+		if (full && cmd != grp->commands)
+			fputc('\n', outf);
+
+		if (!cmd->next) {
+			if (do_sep) {
+				fputc('\n', outf);
+				do_sep = 0;
+			}
+
+			usage_command_internal(cmd->usagestr, cmd->token, full,
+					       1, outf);
+			continue;
+		}
+
+		/* this is an entry point to a nested command group */
+
+		if (!full && cmd != grp->commands)
+			fputc('\n', outf);
+
+		usage_command_group_internal(cmd->next, full, outf);
+
+		if (!full)
+			do_sep = 1;
+	}
+}
+
+void usage_command_group(const struct cmd_group *grp, int full, int err)
+{
+	const char * const *usagestr = grp->usagestr;
+	FILE *outf = err ? stderr : stdout;
+
+	if (usagestr && *usagestr) {
+		fprintf(outf, "usage: %s\n", *usagestr++);
+		while (*usagestr)
+			fprintf(outf, "   or: %s\n", *usagestr++);
+	}
+
+	fputc('\n', outf);
+	usage_command_group_internal(grp, full, outf);
+	fputc('\n', outf);
+
+	if (grp->infostr)
+		fprintf(outf, "%s\n", grp->infostr);
+}
+
+void help_unknown_token(const char *arg, const struct cmd_group *grp)
+{
+	fprintf(stderr, "%s: unknown token '%s'\n", argv0_buf, arg);
+	usage_command_group(grp, 0, 1);
+	exit(1);
+}
+
+void help_ambiguous_token(const char *arg, const struct cmd_group *grp)
+{
+	const struct cmd_struct *cmd = grp->commands;
+
+	fprintf(stderr, "%s: ambiguous token '%s'\n", argv0_buf, arg);
+	fprintf(stderr, "\nDid you mean one of these ?\n");
+
+	for (; cmd->token; cmd++) {
+		if (!prefixcmp(cmd->token, arg))
+			fprintf(stderr, "\t%s\n", cmd->token);
+	}
+
+	exit(1);
+}
+
+void help_command_group(const struct cmd_group *grp, int argc, char **argv)
+{
+	int full = 0;
+
+	if (argc > 1) {
+		if (!strcmp(argv[1], "--full"))
+			full = 1;
+	}
+
+	usage_command_group(grp, full, 0);
+}