Introduce sb2-show, cleanup some warnings

sb2-show allows you to inspect how path/argv/envp mangling
would be done for a given binary. Patch by
lauri.t.aarnio@nokia.com, somewhat cleaned up by
lle@rahina.org.

Signed-off-by: Lauri Leukkunen <lle@rahina.org>

15 files changed, 354 insertions, 57 deletions

diff --git a/AUTHORS b/AUTHORS
index 73e4a07..6054ae7 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1,9 +1,9 @@
 Complete list of authors and their modules:
 
 Lauri Leukkunen <lle@rahina.org>:
-	mapping/*
+	luaif/*
 	preload/*
-	redir_scripts/*
+	lua_scripts/*
 	utils/*
 	include/*
 	scripts/*
@@ -14,3 +14,10 @@ Valtteri Rahkonen <valtteri@rahkonen.fi>:
 Riku Voipio <riku.voipio@movial.fi>:
 	debian/*
 
+Lauri T. Aarnio <lauri.aarnio@iki.fi>:
+	preload/gen-interface.pl
+	preload/interface.master
+	luaif/sb_log.c
+	utils/sb2-logz
+	utils/sb2-show.c
+
diff --git a/Makefile b/Makefile
index 0e4378a..e0715a4 100644
--- a/Makefile
+++ b/Makefile
@@ -27,11 +27,12 @@ PACKAGE_VERSION = "1.99.0.23"
 PACKAGE = "SB2"
 LIBSB2_SONAME = "libsb2.so.1"
 LLBUILD ?= $(SRCDIR)/llbuild
+PROTOTYPEWARNINGS=-Wmissing-prototypes -Wstrict-prototypes
 
 
 # targets variable will be filled by llbuild
 targets = 
-subdirs = luaif preload
+subdirs = luaif preload utils
 
 -include config.mak
 
@@ -96,7 +97,7 @@ install-noarch: $(BUILD_TARGET)
 	install -c -m 755 $(SRCDIR)/utils/sb2-config $(prefix)/bin/sb2-config
 	install -c -m 755 $(SRCDIR)/utils/sb2-build-libtool $(prefix)/bin/sb2-build-libtool
 	install -c -m 755 $(SRCDIR)/utils/dpkg-checkbuilddeps $(prefix)/share/scratchbox2/scripts/dpkg-checkbuilddeps
-	install -c -m 755 $(SRCDIR)/utils/sb2logz $(prefix)/share/scratchbox2/scripts/sb2logz
+	install -c -m 755 $(SRCDIR)/utils/sb2-logz $(prefix)/bin/sb2-logz
 	install -c -m 644 $(SRCDIR)/lua_scripts/main.lua $(prefix)/share/scratchbox2/lua_scripts/main.lua
 	install -c -m 644 $(SRCDIR)/lua_scripts/mapping.lua $(prefix)/share/scratchbox2/lua_scripts/mapping.lua
 	install -c -m 644 $(SRCDIR)/lua_scripts/argvenvp.lua $(prefix)/share/scratchbox2/lua_scripts/argvenvp.lua
@@ -120,6 +121,7 @@ install: install-noarch
 	install -d -m 755 $(prefix)/lib
 	install -d -m 755 $(prefix)/lib/libsb2
 	install -c -m 755 $(OBJDIR)/preload/libsb2.so $(prefix)/lib/libsb2/libsb2.so.$(PACKAGE_VERSION)
+	install -c -m 755 $(OBJDIR)/utils/sb2-show $(prefix)/bin/sb2-show
 	/sbin/ldconfig -n $(prefix)/lib/libsb2
 
 
@@ -128,6 +130,7 @@ multilib_prefix=$(prefix)
 install-multilib: install-noarch
 	$(MAKE) -C obj-32 --include-dir=.. -f ../Makefile SRCDIR=.. do-install-multilib bitness=32
 	$(MAKE) -C obj-64 --include-dir=.. -f ../Makefile SRCDIR=.. do-install-multilib bitness=64
+	install -c -m 755 $(PRI_OBJDIR)/utils/sb2-show $(prefix)/bin/sb2-show
 
 do-install-multilib:
 	install -d -m 755 $(multilib_prefix)/lib$(bitness)
@@ -136,10 +139,17 @@ do-install-multilib:
 	/sbin/ldconfig -n $(multilib_prefix)/lib$(bitness)/libsb2
 
 
-CLEAN_FILES += $(targets) config.status config.log obj-32 obj-64 .configure-multilib
+CLEAN_FILES += $(targets) config.status config.log
 
 # make all object files depend on include/config.h
 
+superclean: clean
+	rm -rf obj-32 obj-64 .configure-multilib
+
+clean-multilib:
+	$(MAKE) -C obj-32 --include-dir .. -f ../Makefile clean
+	$(MAKE) -C obj-64 --include-dir .. -f ../Makefile clean
+
 clean:
 	$(ll_clean)
 
diff --git a/README b/README
index 18c0370..0b519db 100644
--- a/README
+++ b/README
@@ -154,12 +154,34 @@ be created under ~/sb2_logs/ (The above command will also print out the
 exact name and location of the logfile.)
 
 The produced logfile can be quite huge, especially when using the higher
-logging levels. A logfile analyzer script, sb2logz, can be used to extract
+logging levels. A logfile analyzer script, sb2-logz, can be used to extract
 essentials like error and warning messages and path mapping actions from
 the logged information; log level 'info' in enough for anything that
-sb2logz needs. Higher logging levels ('debug', etc) are mostly useful
+sb2-logz needs. Higher logging levels ('debug', etc) are mostly useful
 only for developers of scratchbox 2.
 
+Another useful helper tool is "sb2-show", an utility which can be used to 
+test path and command mapping rules while scratchbox 2 is active.
+
+For example,
+
+$ sb2-show path /etc/apt
+
+$ sb2-show -b apt-get path /etc/apt
+
+will show how the /etc/apt database has been mapped. The latter command
+uses "apt-get" as the name of the calling program (the results may
+be different depending on mapping mode, name of the calling program, etc)
+
+sb2-show can also be used to see how parameters to certain processes will
+be modified:
+
+$ sb2-show exec gcc foo.c
+
+shows which "gcc" would be started inside the sb2 session, together with
+the actual, possibly modified, arguments. The result depends on how sb2 
+was configured (see notes about sb2-init above)
+
 
 
 -- 
diff --git a/include/mapping.h b/include/mapping.h
index 28ce5d6..555c23b 100644
--- a/include/mapping.h
+++ b/include/mapping.h
@@ -19,10 +19,12 @@ enum lua_engine_states {
 	LES_READY
 };
 
-char *scratchbox_path(const char *func_name, const char *path);
-char *scratchbox_path2(const char *binary_name, const char *func_name,
+extern char *scratchbox_path(const char *func_name, const char *path);
+extern char *scratchbox_path2(const char *binary_name, const char *func_name,
 			const char *path);
-int sb_execve_mod(char **file, char ***argv, char ***envp);
-char *emumode_map(const char *path);
+extern char *scratchbox_path3(const char *binary_name, const char *func_name,
+		const char *path, const char *mapping_mode);
+extern int sb_execve_mod(char **file, char ***argv, char ***envp);
+extern char *emumode_map(const char *path);
 
 #endif
diff --git a/luaif/Makefile b/luaif/Makefile
index d0bf565..9426c4d 100644
--- a/luaif/Makefile
+++ b/luaif/Makefile
@@ -2,8 +2,10 @@ LUASRC = luaif/lua-5.1.2/src
 
 objs := $(D)/luaif.o $(D)/sb_log.o $(D)/paths.o $(D)/argvenvp.o
 
+$(D)/sb_log.o: preload/exported.h
+
 luaif/libluaif.a: $(objs)
-luaif/libluaif.a: override CFLAGS := $(CFLAGS) -O2 -g -fPIC -Wall -W -I$(SRCDIR)/$(LUASRC)
+luaif/libluaif.a: override CFLAGS := $(CFLAGS) -O2 -g -fPIC -Wall -W -I$(SRCDIR)/$(LUASRC) -I$(OBJDIR)/preload -I$(SRCDIR)/preload
 luaif/libluaif.a: override LDFLAGS := $(LDFLAGS)
 luaif/libluaif.a: override LIBS := 
 
diff --git a/luaif/paths.c b/luaif/paths.c
index 3a149d0..ce6f43a 100644
--- a/luaif/paths.c
+++ b/luaif/paths.c
@@ -166,12 +166,13 @@ char *scratchbox_path(const char *func_name, const char *path)
 /* make sure to use disable_mapping(m); 
  * to prevent recursive calls to this function
  */
-char *scratchbox_path2(const char *binary_name,
+char *scratchbox_path3(const char *binary_name,
 		const char *func_name,
-		const char *path)
+		const char *path,
+		const char *mapping_mode)
 {	
 	char work_dir[PATH_MAX + 1];
-	char *tmp = NULL, *decolon_path = NULL, *mapping_mode = NULL;
+	char *tmp = NULL, *decolon_path = NULL;
 	char pidlink[17]; /* /proc/2^8/exe */
 	struct lua_instance *luaif;
 
@@ -206,7 +207,9 @@ char *scratchbox_path2(const char *binary_name,
 		exit(1);
 	}
 
-	if (!(mapping_mode = getenv("SBOX_MAPMODE"))) {
+	/* use a sane default for mapping_mode, if not defined by 
+	 * the parameter or environment */
+	if (!mapping_mode && !(mapping_mode = getenv("SBOX_MAPMODE"))) {
 		mapping_mode = "simple";
 	}
 
@@ -281,3 +284,15 @@ char *scratchbox_path2(const char *binary_name,
 	}
 }
 
+char *scratchbox_path2(const char *binary_name,
+		const char *func_name,
+		const char *path)
+{	
+	const char *mapping_mode;
+
+	if (!(mapping_mode = getenv("SBOX_MAPMODE"))) {
+		mapping_mode = "simple";
+	}
+	return(scratchbox_path3(binary_name, func_name, path, mapping_mode));
+}
+
diff --git a/luaif/sb_log.c b/luaif/sb_log.c
index 0b2ec13..64d28f2 100644
--- a/luaif/sb_log.c
+++ b/luaif/sb_log.c
@@ -18,6 +18,11 @@
 #include <string.h>
 
 #include <sb2.h>
+#include <config.h>
+#include <config_hardcoded.h>
+
+#include "libsb2.h"
+#include "exported.h"
 
 /* ===================== Internal state variables =====================
  *
diff --git a/preload/Makefile b/preload/Makefile
index 7c65886..780dd86 100644
--- a/preload/Makefile
+++ b/preload/Makefile
@@ -1,8 +1,5 @@
 objs := wrappers.o libsb2.o sb_exec.o
 
-PROTOTYPEWARNINGS=-Wmissing-prototypes -Wstrict-prototypes
-
-
 ifeq ($(shell uname -s),Linux)
 LIBSB2_LDFLAGS = -Wl,-soname=$(LIBSB2_SONAME) \
 		-Wl,--retain-symbols-file=preload/ldexportlist
diff --git a/preload/gen-interface.pl b/preload/gen-interface.pl
index d22bd18..5380c67 100755
--- a/preload/gen-interface.pl
+++ b/preload/gen-interface.pl
@@ -256,9 +256,6 @@ sub add_function_name_to_symbol_table {
 	my $fn_name = shift;
 
 	if(defined($all_function_names{$fn_name})) {
-		printf "Warning: Multiple references to function '%s'\n",
-			$fn_name;
-		#$num_errors++;
 		return;
 	}
 	$all_function_names{$fn_name} = 1;
diff --git a/preload/interface.master b/preload/interface.master
index cb9f918..af0cd21 100644
--- a/preload/interface.master
+++ b/preload/interface.master
@@ -22,6 +22,14 @@ EXPORT: void _fini(void)
 -- 2. exported functions.
 --    -------------------
 
+-- Functions used by the "sb2show" command:
+EXPORT: char *sb2show__map_path__(const char *binary_name, \
+	const char *mapping_mode, const char *fn_name, const char *pathname)
+EXPORT: int sb2show__execve_mods__( \
+	char *file, \
+	char *const *orig_argv, char *const *orig_envp, \
+	char **new_file, char ***new_argv, char ***new_envp)
+
 --    FIXME: The following two functions do not have anything to do with path
 --    remapping. Instead the implementations in libsb2.c prevent locking of
 --    the shadow file, which I find really hard to understand. Please explain
diff --git a/preload/libsb2.c b/preload/libsb2.c
index d05ef30..baed8bb 100644
--- a/preload/libsb2.c
+++ b/preload/libsb2.c
@@ -528,23 +528,25 @@ void _exit_gate(void (*real__exit_ptr)(int status),
 	const char *realfnname, int status)
 {
 	/* NOTE: Following SB_LOG() call is used by the log
-	 *       postprocessor script "sb2logz". Do not change
+	 *       postprocessor script "sb2-logz". Do not change
 	 *       without making a corresponding change to the script!
 	*/
 	SB_LOG(SB_LOGLEVEL_INFO, "%s: status=%d", realfnname, status);
 	(real__exit_ptr)(status);
 }
 
+
 void _Exit_gate(void (*real__Exit_ptr)(int status),
 	const char *realfnname, int status)
 {
 	/* NOTE: Following SB_LOG() call is used by the log
-	 *       postprocessor script "sb2logz". Do not change
+	 *       postprocessor script "sb2-logz". Do not change
 	 *       without making a corresponding change to the script!
 	*/
 	SB_LOG(SB_LOGLEVEL_INFO, "%s: status=%d", realfnname, status);
 	(real__Exit_ptr)(status);
 }
+//void _Exit_gate() __attribute__ ((noreturn));
 
 /* ---------- */
 
@@ -567,3 +569,18 @@ void *sbox_find_next_symbol(int log_enabled, const char *fn_name)
 	}
 	return(fn_ptr);
 }
+
+/* ---------- */
+char *sb2show__map_path__(const char *binary_name, const char *mapping_mode, 
+        const char *fn_name, const char *pathname)
+{
+	char *mapped__pathname = NULL;
+
+	if (pathname != NULL) {
+		mapped__pathname = scratchbox_path3(binary_name, fn_name,
+			pathname, mapping_mode);
+	}
+	SB_LOG(SB_LOGLEVEL_DEBUG, "%s '%s'", __func__, pathname);
+	return(mapped__pathname);
+}
+
diff --git a/preload/sb_exec.c b/preload/sb_exec.c
index 1fd264f..9693a84 100644
--- a/preload/sb_exec.c
+++ b/preload/sb_exec.c
@@ -511,7 +511,7 @@ int run_hashbang(const char *file, char *const *argv, char *const *envp)
 {
 	int argc, fd, c, i, j, n, ret;
 	char ch;
-	char **p, *ptr, *mapped_interpreter;
+	char *ptr, *mapped_interpreter;
 	char **new_argv;
 	char hashbang[SBOX_MAXPATH]; /* only 60 needed on linux, just be safe */
 	char interpreter[SBOX_MAXPATH];
@@ -527,8 +527,7 @@ int run_hashbang(const char *file, char *const *argv, char *const *envp)
 		return run_app(file, argv, envp);
 	}
 
-	for (argc = 0, p = (char **)argv; *p; p++)
-		argc++;
+	argc = elem_count(argv);
 
 	/* extra element for hashbang argument */
 	new_argv = calloc(argc + 3, sizeof(char *));
@@ -585,33 +584,36 @@ int run_hashbang(const char *file, char *const *argv, char *const *envp)
 	return ret;
 }
 
-int do_exec(const char *exec_fn_name, const char *file,
-		char *const *argv, char *const *envp)
+static char ***duplicate_argv(char *const *argv)
 {
-	char ***my_envp, ***my_argv, **my_file, **p;
-	char *binaryname, *tmp, *mapped_file;
-	int envc = 0, argc = 0, i, has_ld_preload = 0, err = 0;
-	enum binary_type type;
+	int	argc = elem_count(argv);
+	char	**p;
+	int	i;
+	char	***my_argv;
 
-	(void)exec_fn_name; /* not yet used */
+	my_argv = malloc(sizeof(char **));
+	*my_argv = (char **)calloc(argc + 1, sizeof(char *));
+	for (i = 0, p = (char **)argv; *p; p++) {
+		(*my_argv)[i++] = strdup(*p);
+	}
+	(*my_argv)[i] = NULL;
+
+	return(my_argv);
+}
+
+static char ***prepare_envp_for_do_exec(char *binaryname, char *const *envp)
+{
+	char	**p;
+	int	envc = 0;
+	char	***my_envp;
+	int	has_ld_preload = 0;
+	int	i;
+	char	*tmp;
 
 	/* if we have LD_PRELOAD env var set, make sure the new my_envp
 	 * has it as well
 	 */
 
-	if (getenv("SBOX_DISABLE_MAPPING")) {
-		/* just run it, don't worry, be happy! */
-		return sb_next_execve(file, argv, envp);
-	}
-	
-
-	tmp = strdup(file);
-	binaryname = strdup(basename(tmp));
-	free(tmp);
-	
-	my_file = malloc(sizeof(char *));
-	*my_file = strdup(file);
-
 	/* count the environment variables and arguments, also check
 	 * for LD_PRELOAD
 	 */
@@ -620,11 +622,7 @@ int do_exec(const char *exec_fn_name, const char *file,
 			has_ld_preload = 1;
 	}
 
-	for (p=(char **)argv; *p; p++, argc++)
-		;
-
 	my_envp = malloc(sizeof(char **));
-	my_argv = malloc(sizeof(char **));
 
 	if (has_ld_preload || !getenv("LD_PRELOAD")) {
 		*my_envp = (char **)calloc(envc + 2, sizeof(char *));
@@ -667,11 +665,33 @@ int do_exec(const char *exec_fn_name, const char *file,
 	}
 	(*my_envp)[i] = NULL;
 
-	*my_argv = (char **)calloc(argc + 1, sizeof(char *));
-	for (i = 0, p = (char **)argv; *p; p++) {
-		(*my_argv)[i++] = strdup(*p);
+	return(my_envp);
+}
+
+int do_exec(const char *exec_fn_name, const char *file,
+		char *const *argv, char *const *envp)
+{
+	char ***my_envp, ***my_argv, **my_file;
+	char *binaryname, *tmp, *mapped_file;
+	int err = 0;
+	enum binary_type type;
+
+	(void)exec_fn_name; /* not yet used */
+
+	if (getenv("SBOX_DISABLE_MAPPING")) {
+		/* just run it, don't worry, be happy! */
+		return sb_next_execve(file, argv, envp);
 	}
-	(*my_argv)[i] = NULL;
+	
+	tmp = strdup(file);
+	binaryname = strdup(basename(tmp));
+	free(tmp);
+	
+	my_file = malloc(sizeof(char *));
+	*my_file = strdup(file);
+
+	my_envp = prepare_envp_for_do_exec(binaryname, envp);
+	my_argv = duplicate_argv(argv);
 
 	if ((err = sb_execve_mod(my_file, my_argv, my_envp)) != 0) {
 		SB_LOG(SB_LOGLEVEL_ERROR, "argvenvp processing error %i", err);
@@ -682,7 +702,9 @@ int do_exec(const char *exec_fn_name, const char *file,
 	 */
 
 	mapped_file = scratchbox_path("do_exec", *my_file);
-	SB_LOG(SB_LOGLEVEL_DEBUG, "do_exec(): *my_file = %s, mapped_file = %s", *my_file, mapped_file);
+	SB_LOG(SB_LOGLEVEL_DEBUG, 
+		"do_exec(): *my_file = %s, mapped_file = %s", 
+		*my_file, mapped_file);
 
 	type = inspect_binary(mapped_file); /* inspect the completely mangled 
 					     * filename */
@@ -726,3 +748,40 @@ int do_exec(const char *exec_fn_name, const char *file,
 	return sb_next_execve(mapped_file, *my_argv, *my_envp);
 }
 
+/* ---------- */
+int sb2show__execve_mods__(
+	char *file,
+	char *const *orig_argv, char *const *orig_envp,
+	char **new_file, char ***new_argv, char ***new_envp)
+{
+	char *binaryname, *tmp;
+	int err = 0;
+	char ***my_envp, ***my_argv, **my_file;
+
+	SB_LOG(SB_LOGLEVEL_DEBUG, "%s '%s'", __func__, orig_argv[0]);
+
+	tmp = strdup(file);
+	binaryname = strdup(basename(tmp));
+	free(tmp);
+	
+	my_file = malloc(sizeof(char *));
+	*my_file = strdup(file);
+
+	my_envp = prepare_envp_for_do_exec(binaryname, orig_envp);
+	my_argv = duplicate_argv(orig_argv);
+
+	if ((err = sb_execve_mod(my_file, my_argv, my_envp)) != 0) {
+		SB_LOG(SB_LOGLEVEL_ERROR, "argvenvp processing error %i", err);
+		
+		*new_file = NULL;
+		*new_argv = NULL;
+		*new_envp = NULL;
+	} else {
+		*new_file = *my_file;
+		*new_argv = *my_argv;
+		*new_envp = *my_envp;
+	}
+
+	return(0);
+}
+
diff --git a/utils/Makefile b/utils/Makefile
new file mode 100644
index 0000000..3140bfd
--- /dev/null
+++ b/utils/Makefile
@@ -0,0 +1,15 @@
+# beware of namespace collisions, all subdir makefiles are included
+# into the top-level Makefile
+
+$(D)/sb2-show: CFLAGS := $(CFLAGS) -Wall -W -Werror \
+		-I$(SRCDIR)/preload -Ipreload/ $(PROTOTYPEWARNINGS) \
+		-I$(SRCDIR)/include
+
+$(D)/sb2-show.o: preload/exported.h
+$(D)/sb2-show: preload/libsb2.so $(D)/sb2-show.o 
+	$(MKOUTPUTDIR)
+	$(P)LD
+	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
+
+targets := $(targets) $(D)/sb2-show
+
diff --git a/utils/sb2logz b/utils/sb2-logz
index 747d383..4be527f 100755
--- a/utils/sb2logz
+++ b/utils/sb2-logz
@@ -15,7 +15,7 @@ use Getopt::Std;
 
 sub usage {
 	print	"Usage:\n".
-		"\tsb2logz [options]\n".
+		"\tsb2-logz [options]\n".
 		"\t(stdin should be a logfile produced by the sb2 command,\n".
 		"\tsee options '-d' and '-L level' of sb2)\n".
 		"Options:\n".
diff --git a/utils/sb2-show.c b/utils/sb2-show.c
new file mode 100644
index 0000000..b32570d
--- /dev/null
+++ b/utils/sb2-show.c
@@ -0,0 +1,141 @@
+/* sb2-show:
+ * SB2 Mapping rule testingutility
+ *
+ * Copyright (c) 2008 Nokia Corporation. All rights reserved.
+ * Author: Lauri T. Aarnio
+ * Licensed under LGPL version 2.1, see top level LICENSE file for details.
+*/
+
+#include <unistd.h>
+#include <config.h>
+#include <config_hardcoded.h>
+
+#include "libsb2.h"
+#include "exported.h"
+
+static void usage_exit(const char *progname, const char *errmsg, int exitstatus)
+{
+	if (errmsg) 
+		fprintf(stderr, "%s: Error: %s\n", progname, errmsg);
+
+	fprintf(stderr, 
+		"\n%s: Usage:\n"
+		"\t%s [options] command [parameters]\n"
+		"\nOptions:\n"
+		"\t-b binary_name\tshow using binary_name as name of "
+			"the calling program\n"
+		"\t-m mode\t\tshow using named mapping mode "
+			"(default=current mode)\n"
+		"\t-f function\tshow using 'function' as callers name\n"
+		"\nCommands:\n"
+		"\tpath [path1] [path2].."
+			"\tShow mappings of pathnames\n"
+		"\texec file argv0 [argv1] [argv2].."
+			"\tShow execve() modifications\n"
+		"\n'%s' must be executed inside sb2 sandbox"
+			" (see the 'sb2' command)\n",
+		progname, progname, progname);
+
+	exit(exitstatus);
+}
+
+static void command_show_exec(
+	const char *binary_name,
+	const char *mapping_mode,
+	const char *fn_name,
+	const char *progname, 
+	int argc, char **argv)
+{
+	char	*new_file;
+	char	**new_argv;
+	char	**new_envp;
+	char	*mapped_path = NULL;
+	int	i;
+	
+	if (argc < 2) {
+		usage_exit(progname, "Too few parameters for this command", 1);
+	}
+	sb2show__execve_mods__(argv[0], argv, environ,
+		&new_file, &new_argv, &new_envp);
+	printf("File\t%s\n", new_file);
+
+	/* do_exec() will map the path just after argvenvp modifications
+	 * have been done, do that here also
+	*/
+	mapped_path = sb2show__map_path__(binary_name, mapping_mode, fn_name,
+		 new_file);
+	printf("Mapped\t%s\n", mapped_path);
+
+	for (i = 0; new_argv[i]; i++) {
+		printf("argv[%d]\t%s\n", i, new_argv[i]);
+	}
+}
+
+static void command_show_path(const char *binary_name,
+	const char *mapping_mode,
+	const char *fn_name,  char **argv)
+{
+	char	*mapped_path = NULL;
+
+	while (*argv) {
+		mapped_path = sb2show__map_path__(binary_name, mapping_mode, 
+			fn_name, *argv);
+		printf("%s => %s\n", *argv, mapped_path);
+		argv++;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	int	opt;
+	char	*progname = argv[0];
+	char	*mapping_mode = NULL;
+	char	*function_name = "ANYFUNCTION";
+	char	*binary_name = "ANYBINARY";
+	
+#if 0 || defined(enable_this_after_sb2_preload_library_startup_has_been_fixed)
+	/* FIXME: this should be able to check if we are inside the sb2
+	 * sandbox, but that is not currently possible (instead initialization
+	 * of the preload library will fail even before main() is entered.
+	 * this happens because the preload library was not designed to
+	 * be used as ordinary library, which is exactly what we are doing 
+	 * now... initialization code of the library should be modified.
+	*/
+
+	/* check that we are running inside 'sb2' environment */
+	if (!getenv("SBOX_LUA_SCRIPTS") ||
+	   !getenv("SBOX_MAPMODE")) {
+		usage_exit(progname, "Not inside scratchboxed environment", 1);
+	}
+#endif
+
+	while ((opt = getopt(argc, argv, "hm:f:b:")) != -1) {
+		switch (opt) {
+		case 'h': usage_exit(progname, NULL, 0); break;
+		case 'm': mapping_mode = optarg; break;
+		case 'f': function_name = optarg; break;
+		case 'b': binary_name = optarg; break;
+		default: usage_exit(progname, "Illegal option", 1); break;
+		}
+	}
+
+	/* check parameters */
+	if (optind >= argc) 
+		usage_exit(progname, "Wrong number of parameters", 1);
+	if (!mapping_mode) 
+		mapping_mode = getenv("SBOX_MAPMODE");
+
+	/* params ok, go and perform the action */
+	if (!strcmp(argv[optind], "path")) {
+		command_show_path(binary_name, mapping_mode, function_name, 
+			argv + optind + 1);
+	} else if (!strcmp(argv[optind], "exec")) {
+		command_show_exec(binary_name, mapping_mode, function_name,
+			progname, argc - (optind+1), argv + optind + 1);
+	} else {
+		usage_exit(progname, "Unknown command", 1);
+	}
+
+	return(0);
+}
+