120 lines
3.1 KiB
C
Executable File
120 lines
3.1 KiB
C
Executable File
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <getopt.h>
|
|
#include <string.h>
|
|
#include <dlfcn.h>
|
|
|
|
extern char *optarg;
|
|
extern int optind, opterr, optopt;
|
|
|
|
static struct option long_options[] = {
|
|
{"library", required_argument, 0, 'l'},
|
|
{"symbol", required_argument, 0, 's'},
|
|
{"help", no_argument, 0, 'h'},
|
|
{0, 0, 0, 0},
|
|
};
|
|
|
|
/* This array must parallel long_options[] */
|
|
static const char *descriptions[] = {
|
|
"specify a library path to look up symbol",
|
|
"specify symbol to look up",
|
|
"print this help screen",
|
|
};
|
|
|
|
void print_help(const char *name) {
|
|
fprintf(stdout,
|
|
"invokation:\n"
|
|
"\t%s [-l <libname>] -s <symbol name>\n"
|
|
"\t%s -h\n\n", name, name);
|
|
fprintf(stdout, "options:\n");
|
|
struct option *opt = long_options;
|
|
const char **desc = descriptions;
|
|
while (opt->name) {
|
|
fprintf(stdout, "\t-%c/--%s%s: %s\n",
|
|
opt->val,
|
|
opt->name,
|
|
(opt->has_arg ? " (argument)" : ""),
|
|
*desc);
|
|
opt++;
|
|
desc++;
|
|
}
|
|
}
|
|
|
|
int get_options(int argc, char **argv, char **lib, char **sym)
|
|
{
|
|
int c;
|
|
|
|
*lib = 0;
|
|
*sym = 0;
|
|
|
|
while (1) {
|
|
/* getopt_long stores the option index here. */
|
|
int option_index = 0;
|
|
|
|
c = getopt_long (argc, argv,
|
|
"l:s:h",
|
|
long_options,
|
|
&option_index);
|
|
/* Detect the end of the options. */
|
|
if (c == -1) break;
|
|
|
|
switch (c) {
|
|
case 'l':
|
|
*lib = strdup(optarg);
|
|
break;
|
|
case 's':
|
|
*sym = strdup(optarg);
|
|
break;
|
|
case 'h': print_help(argv[0]); exit(EXIT_FAILURE); break;
|
|
case '?':
|
|
/* getopt_long already printed an error message. */
|
|
break;
|
|
default:
|
|
fprintf(stderr, "Unknown option");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
}
|
|
|
|
return optind;
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
char *libname, *symname, *prog = *argv;
|
|
|
|
get_options(argc, argv, &libname, &symname);
|
|
|
|
if (symname == NULL) {
|
|
fprintf(stderr, "You must specify a symbol!\n");
|
|
print_help(prog);
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
{
|
|
const char *dlerr;
|
|
void *handle, *symbol;
|
|
|
|
printf("opening library [%s]\n", libname);
|
|
dlerr = dlerror();
|
|
handle = libname ? dlopen(libname, RTLD_NOW) : RTLD_DEFAULT;
|
|
dlerr = dlerror();
|
|
if (dlerr != NULL) fprintf(stderr, "dlopen() error: %s\n", dlerr);
|
|
|
|
printf("opening symbol [%s]\n", symname);
|
|
symbol = dlsym(handle, symname);
|
|
dlerr = dlerror();
|
|
if (dlerr != NULL) fprintf(stderr, "dlsym() error: %s\n", dlerr);
|
|
|
|
printf("closing library [%s]\n", libname);
|
|
dlclose(handle);
|
|
dlerr = dlerror();
|
|
if (dlerr != NULL) fprintf(stderr, "dlclose() error: %s\n", dlerr);
|
|
else printf("successfully opened symbol\n");
|
|
}
|
|
|
|
if (libname != NULL) free(libname);
|
|
if (symname != NULL) free(symname);
|
|
return 0;
|
|
}
|