fix(fs): resolve temporary directory and handle errors correctly

examples/cache/src/main.c

@@ -1,12 +1,25 @@
+#include <errno.h>
+#include <string.h>
 #include <stdio.h>
 #include <stddef.h>
-#include <linux/limits.h>
+#include <limits.h>
 #include "onus/fs.h"
 
 int main() {
-    char tmp[PATH_MAX];
-    int status = onus_fs_make_tmp(tmp, sizeof(tmp), NULL);
-    printf("Got status: %d. Path: %s\n", status, tmp);
-    // onus_fs_del_tmp(tmp);
+    char tmp[PATH_MAX], tmpfile[PATH_MAX];
+    FILE *f;
+    int status;
+
+    status = onus_fs_make_tmp(tmp, sizeof(tmp), NULL);
+    printf("onus_fs_make_tmp: %d. Path: %s\n", status, tmp);
+    
+    /* TODO: Unsafe code */
+    sprintf(tmpfile, "%s/test.txt", tmp);
+    f = fopen(tmpfile, "w");
+    printf("fopen: %d\n", f ? 0 : errno);
+    if (f) fclose(f);
+    
+    status = onus_fs_del_tmp(tmp);
+    printf("onus_fs_del_tmp: %d\n", status);
     return 0;
 }

pkg/fs/src/tmp.c

@@ -7,27 +7,43 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <limits.h>
+
+/* TODO: Add def for windows */
+static const char *kTemporaryDirectoryPathDefault = "/tmp";
 
 int onus_fs_make_tmp(char *path, onus_size_t path_sz, const char *suffix) {
-  char *npath = NULL;
+  char *npath = NULL, *tmpdpath = NULL;
+  const char *tmpdir;
   int ret;
 
-  if (suffix == NULL) suffix = "";
-  npath = malloc(strlen(suffix) + 1 + 6);
-  sprintf(npath, "%sXXXXXX", suffix);
-  npath = mkdtemp(npath);
+  /* Determine temporary directory path */
+  tmpdir = getenv("TMPDIR");
+  if (tmpdir == NULL) tmpdir = kTemporaryDirectoryPathDefault;
+  tmpdpath = malloc(PATH_MAX);
 
-  if (errno == EACCES) {
-    ret = ONUS_E_PERMISSION_ERROR;
-    goto end;
-  } else if (errno != 0) {
+  if (realpath(tmpdir, tmpdpath) == NULL) {
     ret = ONUS_E_FS_ERROR;
     goto end;
   }
 
+  if (suffix == NULL) suffix = "";
+  npath = malloc(strlen(tmpdpath) + strlen(suffix) + 8);
+  sprintf(npath, "%s/%sXXXXXX", tmpdpath, suffix);
+
+  if (mkdtemp(npath) == NULL) {
+    if (errno == EACCES) {
+      ret = ONUS_E_PERMISSION_ERROR;
+      goto end;
+    } else if (errno != 0) {
+      ret = ONUS_E_FS_ERROR;
+      goto end;
+    }
+  }
+
   if (onus_nstrcpy(path, npath, path_sz) + 1 > path_sz) {
     ret = ONUS_E_BUFFER_TOO_SMALL;
-    goto clean;
+    goto clean; /* Automatically delete dir on error */
   }
 
   ret = ONUS_SUCCESS;
@@ -37,30 +53,19 @@ clean:
 end:
   if (npath)
     free(npath);
+  if (tmpdpath)
+    free(tmpdpath);
   return ret;
 }
 
 static int unlink_cb(const char *filename, const struct stat *status, int flag,
                      struct FTW *info) {
-  if (!remove(filename))
+                      int err;
+  if (remove(filename))
     return ONUS_E_FS_ERROR;
   return 0;
 }
 
-/**
- * Deletes a temporary directory created using onus_fs_make_tmp. Does not
- * perform any checks to guarantee it was created using said function. Be
- * careful when using as it could erase non-temporary directories if misused.
- * (Will not delete files mounted in subdirectories, and will return
- * ONUS_E_FS_ERR instead)
- *
- * Will stilll return success if the directory is missing, as the user may
- * choose to delete it while the program is running
- * @param path: Path to temporary directory to delete
- * @returns ONUS_SUCCESS if directory was deleted successfully, or no longer
- * exists, ONUS_E_PERMISSION_ERROR if failed to delete the requested path,
- * ONUS_E_FS_ERR for unspecified file system errors
- */
 int onus_fs_del_tmp(const char *path) {
   int err;