Немного поздно, но все ответы были специфичны для Linux.
Если вам нужен также Unix, то вам нужно это:
char * getExecPath (char * path,size_t dest_len, char * argv0)
{
char * baseName = NULL;
char * systemPath = NULL;
char * candidateDir = NULL;
/* the easiest case: we are in linux */
size_t buff_len;
if (buff_len = readlink ("/proc/self/exe", path, dest_len - 1) != -1)
{
path [buff_len] = '\0';
dirname (path);
strcat (path, "/");
return path;
}
/* Ups... not in linux, no guarantee */
/* check if we have something like execve("foobar", NULL, NULL) */
if (argv0 == NULL)
{
/* we surrender and give current path instead */
if (getcwd (path, dest_len) == NULL) return NULL;
strcat (path, "/");
return path;
}
/* argv[0] */
/* if dest_len < PATH_MAX may cause buffer overflow */
if ((realpath (argv0, path)) && (!access (path, F_OK)))
{
dirname (path);
strcat (path, "/");
return path;
}
/* Current path */
baseName = basename (argv0);
if (getcwd (path, dest_len - strlen (baseName) - 1) == NULL)
return NULL;
strcat (path, "/");
strcat (path, baseName);
if (access (path, F_OK) == 0)
{
dirname (path);
strcat (path, "/");
return path;
}
/* Try the PATH. */
systemPath = getenv ("PATH");
if (systemPath != NULL)
{
dest_len--;
systemPath = strdup (systemPath);
for (candidateDir = strtok (systemPath, ":"); candidateDir != NULL; candidateDir = strtok (NULL, ":"))
{
strncpy (path, candidateDir, dest_len);
strncat (path, "/", dest_len);
strncat (path, baseName, dest_len);
if (access(path, F_OK) == 0)
{
free (systemPath);
dirname (path);
strcat (path, "/");
return path;
}
}
free(systemPath);
dest_len++;
}
/* again someone has use execve: we dont knowe the executable name; we surrender and give instead current path */
if (getcwd (path, dest_len - 1) == NULL) return NULL;
strcat (path, "/");
return path;
}
РЕДАКТИРОВАНИЕ: Исправлена ошибка, о которой сообщил Марк Лаката.