static char _clar_path[4096];
static int
is_valid_tmp_path(const char *path)
{
STAT_T st;
if (stat(path, &st) != 0)
return 0;
if (!S_ISDIR(st.st_mode))
return 0;
return (access(path, W_OK) == 0);
}
static int
find_tmp_path(char *buffer, size_t length)
{
#ifndef _WIN32
static const size_t var_count = 5;
static const char *env_vars[] = {
"CLAR_TMP", "TMPDIR", "TMP", "TEMP", "USERPROFILE"
};
size_t i;
for (i = 0; i < var_count; ++i) {
const char *env = getenv(env_vars[i]);
if (!env)
continue;
if (is_valid_tmp_path(env)) {
strncpy(buffer, env, length);
return 0;
}
}
/* If the environment doesn't say anything, try to use /tmp */
if (is_valid_tmp_path("/tmp")) {
strncpy(buffer, "/tmp", length);
return 0;
}
#else
DWORD env_len;
if ((env_len = GetEnvironmentVariable("CLAR_TMP", buffer, length)) > 0 &&
env_len < length)
return 0;
if (GetTempPath((DWORD)length, buffer))
return 0;
#endif
/* This system doesn't like us, try to use the current directory */
if (is_valid_tmp_path(".")) {
strncpy(buffer, ".", length);
return 0;
}
return -1;
}
static void clar_unsandbox(void)
{
if (_clar_path[0] == '\0')
return;
chdir("..");
fs_rm(_clar_path);
}
static int build_sandbox_path(void)
{
const char path_tail[] = "clar_tmp_XXXXXX";
size_t len;
if (find_tmp_path(_clar_path, sizeof(_clar_path)) < 0)
return -1;
len = strlen(_clar_path);
#ifdef _WIN32
{ /* normalize path to POSIX forward slashes */
size_t i;
for (i = 0; i < len; ++i) {
if (_clar_path[i] == '\\')
_clar_path[i] = '/';
}
}
#endif
if (_clar_path[len - 1] != '/') {
_clar_path[len++] = '/';
}
strncpy(_clar_path + len, path_tail, sizeof(_clar_path) - len);
#if defined(__MINGW32__)
if (_mktemp(_clar_path) == NULL)
return -1;
if (mkdir(_clar_path, 0700) != 0)
return -1;
#elif defined(_WIN32)
if (_mktemp_s(_clar_path, sizeof(_clar_path)) != 0)
return -1;
if (mkdir(_clar_path, 0700) != 0)
return -1;
#else
if (mkdtemp(_clar_path) == NULL)
return -1;
#endif
return 0;
}
static int clar_sandbox(void)
{
if (_clar_path[0] == '\0' && build_sandbox_path() < 0)
return -1;
if (chdir(_clar_path) != 0)
return -1;
return 0;
}
