/* Finds out a relative path from first to second, i.e. goes as many ..
* as needed up in first and then goes down using second */
char *diff_two_paths (const char *first, const char *second)
{
char *p, *q, *r, *s, *buf = 0;
int i, j, prevlen = -1, currlen;
char *my_first = NULL, *my_second = NULL;
my_first = resolve_symlinks (first);
if (my_first == NULL)
return NULL;
for (j = 0; j < 2; j++) {
p = my_first;
if (j) {
my_second = resolve_symlinks (second);
if (my_second == NULL) {
g_free (my_first);
return buf;
}
}
q = my_second;
for (;;) {
r = strchr (p, PATH_SEP);
s = strchr (q, PATH_SEP);
if (!r || !s)
break;
*r = 0; *s = 0;
if (strcmp (p, q)) {
*r = PATH_SEP; *s = PATH_SEP;
break;
} else {
*r = PATH_SEP; *s = PATH_SEP;
}
p = r + 1;
q = s + 1;
}
p--;
for (i = 0; (p = strchr (p + 1, PATH_SEP)) != NULL; i++);
currlen = (i + 1) * 3 + strlen (q) + 1;
if (j) {
if (currlen < prevlen)
g_free (buf);
else {
g_free (my_first);
g_free (my_second);
return buf;
}
}
p = buf = g_malloc (currlen);
prevlen = currlen;
for (; i >= 0; i--, p += 3)
strcpy (p, "../");
strcpy (p, q);
}
g_free (my_first);
g_free (my_second);
return buf;
}
/*
* find_my_exec -- find an absolute path to a valid executable
*
* argv0 is the name passed on the command line
* retpath is the output area (must be of size MAXPGPATH)
* Returns 0 if OK, -1 if error.
*
* The reason we have to work so hard to find an absolute path is that
* on some platforms we can't do dynamic loading unless we know the
* executable's location. Also, we need a full path not a relative
* path because we will later change working directory. Finally, we want
* a true path not a symlink location, so that we can locate other files
* that are part of our installation relative to the executable.
*
* This function is not thread-safe because it calls validate_exec(),
* which calls getgrgid(). This function should be used only in
* non-threaded binaries, not in library routines.
*/
int
find_my_exec(const char *argv0, char *retpath)
{
char cwd[MAXPGPATH],
test_path[MAXPGPATH];
char *path;
if (!getcwd(cwd, MAXPGPATH))
{
log_error(_("could not identify current directory: %s"),
strerror(errno));
return -1;
}
/*
* If argv0 contains a separator, then PATH wasn't used.
*/
if (first_dir_separator(argv0) != NULL)
{
if (is_absolute_path(argv0))
StrNCpy(retpath, argv0, MAXPGPATH);
else
join_path_components(retpath, cwd, argv0);
canonicalize_path(retpath);
if (validate_exec(retpath) == 0)
return resolve_symlinks(retpath);
log_error(_("invalid binary \"%s\""), retpath);
return -1;
}
#ifdef WIN32
/* Win32 checks the current directory first for names without slashes */
join_path_components(retpath, cwd, argv0);
if (validate_exec(retpath) == 0)
return resolve_symlinks(retpath);
#endif
/*
* Since no explicit path was supplied, the user must have been relying on
* PATH. We'll search the same PATH.
*/
if ((path = getenv("PATH")) && *path)
{
char *startp = NULL,
*endp = NULL;
do
{
if (!startp)
startp = path;
else
startp = endp + 1;
endp = first_path_separator(startp);
if (!endp)
endp = startp + strlen(startp); /* point to end */
StrNCpy(test_path, startp, Min(endp - startp + 1, MAXPGPATH));
if (is_absolute_path(test_path))
join_path_components(retpath, test_path, argv0);
else
{
join_path_components(retpath, cwd, test_path);
join_path_components(retpath, retpath, argv0);
}
canonicalize_path(retpath);
switch (validate_exec(retpath))
{
case 0: /* found ok */
return resolve_symlinks(retpath);
case -1: /* wasn't even a candidate, keep looking */
break;
case -2: /* found but disqualified */
log_error(_("could not read binary \"%s\""),
retpath);
break;
}
} while (*endp);
}
log_error(_("could not find a \"%s\" to execute"), argv0);
return -1;
}
char *
diff_two_paths (const vfs_path_t * vpath1, const vfs_path_t * vpath2)
{
char *p, *q, *r, *s, *buf = NULL;
int i, j, prevlen = -1, currlen;
char *my_first = NULL, *my_second = NULL;
my_first = resolve_symlinks (vpath1);
if (my_first == NULL)
goto ret;
my_second = resolve_symlinks (vpath2);
if (my_second == NULL)
goto ret;
for (j = 0; j < 2; j++)
{
p = my_first;
q = my_second;
while (TRUE)
{
r = strchr (p, PATH_SEP);
s = strchr (q, PATH_SEP);
if (r == NULL || s == NULL)
break;
*r = '\0';
*s = '\0';
if (strcmp (p, q) != 0)
{
*r = PATH_SEP;
*s = PATH_SEP;
break;
}
*r = PATH_SEP;
*s = PATH_SEP;
p = r + 1;
q = s + 1;
}
p--;
for (i = 0; (p = strchr (p + 1, PATH_SEP)) != NULL; i++)
;
currlen = (i + 1) * 3 + strlen (q) + 1;
if (j != 0)
{
if (currlen < prevlen)
g_free (buf);
else
goto ret;
}
p = buf = g_malloc (currlen);
prevlen = currlen;
for (; i >= 0; i--, p += 3)
strcpy (p, "../");
strcpy (p, q);
}
ret:
g_free (my_first);
g_free (my_second);
return buf;
}