Function toml_write_atomic

src/cli/config_toml_edit.c:615–710

}

static int toml_write_atomic(const char *path, const char *old_data, size_t old_len,
                             const char *new_data, size_t new_len,
                             const toml_file_snapshot_t *snapshot) {
    if (old_len > TOML_EDIT_MAX_BYTES || new_len > TOML_EDIT_MAX_BYTES) {
        return TOML_EDIT_ERR;
    }
    if (old_len == new_len && (old_len == 0 || memcmp(old_data, new_data, old_len) == 0)) {
        return TOML_EDIT_OK;
    }
    size_t path_len = strlen(path);
    static const char suffix[] = ".XXXXXX";
    if (path_len > SIZE_MAX - sizeof(suffix)) {
        return TOML_EDIT_ERR;
    }
    char *temp_path = (char *)malloc(path_len + sizeof(suffix));
    if (!temp_path) {
        return TOML_EDIT_ERR;
    }
    memcpy(temp_path, path, path_len);
    memcpy(temp_path + path_len, suffix, sizeof(suffix));

    int fd = cbm_mkstemp(temp_path);
    if (fd < 0) {
        free(temp_path);
        return TOML_EDIT_ERR;
    }
    FILE *file = toml_fdopen(fd, "wb");
    if (!file) {
        (void)toml_close(fd);
        (void)cbm_unlink(temp_path);
        free(temp_path);
        return TOML_EDIT_ERR;
    }

    int failed = new_len != 0 && fwrite(new_data, 1, new_len, file) != new_len;
    if (!failed && fflush(file) != 0) {
        failed = 1;
    }
#ifndef _WIN32
    if (!failed && snapshot->exists &&
        fchown(cbm_fileno(file), snapshot->owner, snapshot->group) != 0) {
        failed = 1;
    }
    mode_t mode = snapshot->exists ? snapshot->mode & 0777U : 0600U;
    if (!failed && fchmod(cbm_fileno(file), mode) != 0) {
        failed = 1;
    }
#endif
    if (!failed && TOML_SYNC(cbm_fileno(file)) != 0) {
        failed = 1;
    }
    if (fclose(file) != 0) {
        failed = 1;
    }
    if (failed) {
        (void)cbm_unlink(temp_path);
        free(temp_path);
        return TOML_EDIT_ERR;