Update documentation generator so that it sucks less

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

applets/usage_pod.c

@@ -0,0 +1,97 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright (C) 2009 Denys Vlasenko.
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+#include <unistd.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdio.h>
+
+/* Just #include "autoconf.h" doesn't work for builds in separate
+ * object directory */
+#include "autoconf.h"
+
+#define SKIP_applet_main
+#define ALIGN1 /* nothing, just to placate applet_tables.h */
+#define ALIGN2 /* nothing, just to placate applet_tables.h */
+#include "applet_tables.h"
+
+/* Since we can't use platform.h, have to do this again by hand: */
+#if ENABLE_NOMMU
+# define BB_MMU 0
+# define USE_FOR_NOMMU(...) __VA_ARGS__
+# define USE_FOR_MMU(...)
+#else
+# define BB_MMU 1
+# define USE_FOR_NOMMU(...)
+# define USE_FOR_MMU(...) __VA_ARGS__
+#endif
+
+static const char usage_messages[] = ""
+#define MAKE_USAGE
+#include "usage.h"
+#include "applets.h"
+;
+
+int main(void)
+{
+	const char *names;
+	const char *usage;
+	int col, len2;
+
+	col = 0;
+	names = applet_names;
+	while (*names) {
+		len2 = strlen(names) + 2;
+		if (col >= 76 - len2) {
+			printf(",\n");
+			col = 0;
+		}
+		if (col == 0) {
+			col = 6;
+			printf("\t");
+		} else {
+			printf(", ");
+		}
+		printf(names);
+		col += len2;
+		names += len2 - 1;
+	}
+	printf("\n\n");
+
+	printf("=head1 COMMAND DESCRIPTIONS\n\n");
+	printf("=over 4\n\n");
+
+	names = applet_names;
+	usage = usage_messages;
+	while (*names && usage) {
+		if (*names >= 'a' && *names <= 'z'
+		 && *usage != NOUSAGE_STR[0]
+		) {
+			printf("=item B<%s>\n\n", names);
+			printf("%s %s\n\n", names, usage);
+		}
+		names += strlen(names) + 1;
+		usage += strlen(usage) + 1;
+	}
+	return 0;
+}
+
+/* TODO: we used to make options bold with B<> and output an example too:
+
+=item B<cat>
+
+cat [B<-u>] [FILE]...
+
+Concatenate FILE(s) and print them to stdout
+
+Options:
+        -u      Use unbuffered i/o (ignored)
+
+Example:
+        $ cat /proc/uptime
+        110716.72 17.67
+
+*/