modinfo: new applet

function                                             old     new   delta
modinfo_main                                           -     307    +307
modinfo                                                -     280    +280
packed_usage                                       27037   27131     +94
display                                                -      74     +74
static.shortcuts                                       -      24     +24
applet_names                                        2254    2262      +8
applet_main                                         1324    1328      +4
applet_nameofs                                       662     664      +2
------------------------------------------------------------------------------
(add/remove: 5/0 grow/shrink: 4/0 up/down: 793/0)             Total: 793 bytes

Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

modutils/Config.src

@@ -5,6 +5,8 @@
 
 menu "Linux Module Utilities"
 
+INSERT
+
 config MODPROBE_SMALL
 	bool "Simplified modutils"
 	default y

modutils/Kbuild.src

@@ -5,6 +5,7 @@
 # Licensed under the GPL v2, see the file LICENSE in this tarball.
 
 lib-y:=
+INSERT
 lib-$(CONFIG_MODPROBE_SMALL)      += modprobe-small.o
 lib-$(CONFIG_DEPMOD)              += depmod.o modutils.o
 lib-$(CONFIG_INSMOD)              += insmod.o modutils.o

modutils/modinfo.c

@@ -0,0 +1,150 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * modinfo - retrieve module info
+ * Copyright (c) 2008 Pascal Bellard
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+//applet:IF_MODINFO(APPLET(modinfo, _BB_DIR_SBIN, _BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_MODINFO) += modinfo.o
+
+//config:config MODINFO
+//config:	bool "modinfo"
+//config:	default y
+//config:	help
+//config:	  Show information about a Linux Kernel module
+
+#include <fnmatch.h>
+#include <sys/utsname.h> /* uname() */
+#include "libbb.h"
+#include "modutils.h"
+
+
+enum {
+	OPT_TAGS = (1 << 6) - 1,
+	OPT_F = (1 << 6), /* field name */
+	OPT_0 = (1 << 7),  /* \0 as separator */
+};
+
+struct modinfo_env {
+	char *field;
+	int tags;
+};
+
+static int display(const char *data, const char *pattern, int flag)
+{
+	if (flag) {
+		int n = printf("%s:", pattern);
+		while (n++ < 16)
+			bb_putchar(' ');
+	}
+	return printf("%s%c", data, (option_mask32 & OPT_0) ? '\0' : '\n');
+}
+
+static void modinfo(const char *path, struct modinfo_env *env)
+{
+	static const char *const shortcuts[] = {
+		"filename",
+		"description",
+		"author",
+		"license",
+		"vermagic",
+		"parm",
+	};
+	size_t len;
+	int j, length;
+	char *ptr, *the_module;
+	const char *field = env->field;
+	int tags = env->tags;
+
+	if (tags & 1) { /* filename */
+		display(path, shortcuts[0], 1 != tags);
+	}
+	len = MAXINT(ssize_t);
+	the_module = xmalloc_open_zipped_read_close(path, &len);
+	if (!the_module)
+		return;
+	if (field)
+		tags |= OPT_F;
+	for (j = 1; (1<<j) & (OPT_TAGS + OPT_F); j++) {
+		const char *pattern = field;
+		if ((1<<j) & OPT_TAGS)
+			pattern = shortcuts[j];
+		if (!((1<<j) & tags))
+			continue;
+		length = strlen(pattern);
+		ptr = the_module;
+		while (1) {
+			ptr = memchr(ptr, *pattern, len - (ptr - (char*)the_module));
+			if (ptr == NULL) /* no occurance left, done */
+				break;
+			if (strncmp(ptr, pattern, length) == 0 && ptr[length] == '=') {
+				ptr += length + 1;
+				ptr += display(ptr, pattern, (1<<j) != tags);
+			}
+			++ptr;
+		}
+	}
+	free(the_module);
+}
+
+//usage:#define modinfo_trivial_usage
+//usage:       "[-adlp0] [-F keyword] MODULE"
+//usage:#define modinfo_full_usage "\n\n"
+//usage:       "Options:"
+//usage:     "\n	-a		Shortcut for '-F author'"
+//usage:     "\n	-d		Shortcut for '-F description'"
+//usage:     "\n	-l		Shortcut for '-F license'"
+//usage:     "\n	-p		Shortcut for '-F parm'"
+//usage:     "\n	-F keyword	Keyword to look for"
+//usage:     "\n	-0		Separate output with NULs"
+//usage:#define modinfo_example_usage
+//usage:       "$ modinfo -F vermagic loop\n"
+
+int modinfo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int modinfo_main(int argc UNUSED_PARAM, char **argv)
+{
+	struct modinfo_env env;
+	char name[MODULE_NAME_LEN];
+	struct utsname uts;
+	parser_t *p;
+	char *colon, *tokens[2];
+	unsigned opts;
+	unsigned i;
+
+	env.field = NULL;
+	opt_complementary = "-1"; /* minimum one param */
+	opts = getopt32(argv, "fdalvpF:0", &env.field);
+	env.tags = opts & OPT_TAGS ? opts & OPT_TAGS : OPT_TAGS;
+	argv += optind;
+
+	uname(&uts);
+	p = config_open2(
+		concat_path_file(
+			concat_path_file(CONFIG_DEFAULT_MODULES_DIR, uts.release),
+			CONFIG_DEFAULT_DEPMOD_FILE),
+		xfopen_for_read
+	);
+
+	while (config_read(p, tokens, 2, 1, "# \t", PARSE_NORMAL)) {
+		colon = last_char_is(tokens[0], ':');
+		if (colon == NULL)
+			continue;
+		*colon = '\0';
+		filename2modname(tokens[0], name);
+		for (i = 0; argv[i]; i++) {
+			if (fnmatch(argv[i], name, 0) == 0) {
+				modinfo(tokens[0], &env);
+				argv[i] = (char *) "";
+			}
+		}
+	}
+	for (i = 0; argv[i]; i++) {
+		if (argv[i][0]) {
+			modinfo(argv[i], &env);
+		}
+	}
+	return 0;
+}