1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <stdio.h>
30 #include <unistd.h>
31 #include <stdlib.h>
32 #include <getopt.h>
33 #include <string.h>
34 #include <dlfcn.h>
35
36 extern char *optarg;
37 extern int optind, opterr, optopt;
38
39 static struct option long_options[] = {
40 {"library", required_argument, 0, 'l'},
41 {"symbol", required_argument, 0, 's'},
42 {"help", no_argument, 0, 'h'},
43 {0, 0, 0, 0},
44 };
45
46 /* This array must parallel long_options[] */
47 static const char *descriptions[] = {
48 "specify a library path to look up symbol",
49 "specify symbol to look up",
50 "print this help screen",
51 };
52
print_help(const char * name)53 void print_help(const char *name) {
54 fprintf(stdout,
55 "invokation:\n"
56 "\t%s [-l <libname>] -s <symbol name>\n"
57 "\t%s -h\n\n", name, name);
58 fprintf(stdout, "options:\n");
59 struct option *opt = long_options;
60 const char **desc = descriptions;
61 while (opt->name) {
62 fprintf(stdout, "\t-%c/--%s%s: %s\n",
63 opt->val,
64 opt->name,
65 (opt->has_arg ? " (argument)" : ""),
66 *desc);
67 opt++;
68 desc++;
69 }
70 }
71
get_options(int argc,char ** argv,char ** lib,char ** sym)72 int get_options(int argc, char **argv, char **lib, char **sym)
73 {
74 int c;
75
76 *lib = 0;
77 *sym = 0;
78
79 while (1) {
80 /* getopt_long stores the option index here. */
81 int option_index = 0;
82
83 c = getopt_long (argc, argv,
84 "l:s:h",
85 long_options,
86 &option_index);
87 /* Detect the end of the options. */
88 if (c == -1) break;
89
90 switch (c) {
91 case 'l':
92 *lib = strdup(optarg);
93 break;
94 case 's':
95 *sym = strdup(optarg);
96 break;
97 case 'h': print_help(argv[0]); exit(EXIT_FAILURE); break;
98 case '?':
99 /* getopt_long already printed an error message. */
100 break;
101 default:
102 fprintf(stderr, "Unknown option");
103 exit(EXIT_FAILURE);
104 }
105 }
106
107 return optind;
108 }
109
main(int argc,char ** argv)110 int main(int argc, char **argv)
111 {
112 char *libname, *symname, *prog = *argv;
113
114 get_options(argc, argv, &libname, &symname);
115
116 if (symname == NULL) {
117 fprintf(stderr, "You must specify a symbol!\n");
118 print_help(prog);
119 exit(EXIT_FAILURE);
120 }
121
122 {
123 const char *dlerr;
124 void *handle, *symbol;
125
126 printf("opening library [%s]\n", libname);
127 dlerr = dlerror();
128 handle = libname ? dlopen(libname, RTLD_NOW) : RTLD_DEFAULT;
129 dlerr = dlerror();
130 if (dlerr != NULL) fprintf(stderr, "dlopen() error: %s\n", dlerr);
131
132 printf("opening symbol [%s]\n", symname);
133 symbol = dlsym(handle, symname);
134 dlerr = dlerror();
135 if (dlerr != NULL) fprintf(stderr, "dlsym() error: %s\n", dlerr);
136
137 printf("closing library [%s]\n", libname);
138 dlclose(handle);
139 dlerr = dlerror();
140 if (dlerr != NULL) fprintf(stderr, "dlclose() error: %s\n", dlerr);
141 else printf("successfully opened symbol\n");
142 }
143
144 if (libname != NULL) free(libname);
145 if (symname != NULL) free(symname);
146 return 0;
147 }
148