1# Copyright (c) 2020 Nordic Semiconductor ASA
2# SPDX-License-Identifier: Apache-2.0
3
4"""
5Helper functions used by gen_kconfig_rest.py and gen_devicetree_rest.py.
6"""
7
8import errno
9
10def write_if_updated(path, s):
11    """
12    Writes 's' as the contents of <out_dir>/<filename>, but only if it
13    differs from the current contents of the file. This avoids unnecessary
14    timestamp updates, which trigger documentation rebuilds.
15
16    Returns True if the file was updated, False otherwise.
17    """
18
19    try:
20        with open(path, "r", encoding="utf-8") as f:
21            if s == f.read():
22                return False
23    except OSError as e:
24        if e.errno != errno.ENOENT:
25            raise
26
27    with open(path, "w", encoding="utf-8") as f:
28        f.write(s)
29    return True
30