Function jl_write_atomic

src/cli/config_json_like.c:1596–1724

}

static int jl_write_atomic(const char *path, const char *content, size_t length,
                           const char *expected_content, size_t expected_length,
                           const jl_file_snapshot_t *expected_snapshot) {
    if (jl_ensure_parent(path) != 0) {
        return -1;
    }
    size_t path_length = strlen(path);
    enum { TEMP_SUFFIX_SPACE = 80 };
    if (path_length > SIZE_MAX - TEMP_SUFFIX_SPACE) {
        return -1;
    }
    size_t temp_capacity = path_length + TEMP_SUFFIX_SPACE;
    char *temp_path = malloc(temp_capacity);
    if (!temp_path) {
        return -1;
    }

    FILE *file = NULL;
    for (unsigned attempt = 0; attempt < 64U; attempt++) {
        unsigned sequence = atomic_fetch_add_explicit(&jl_temp_sequence, 1U, memory_order_relaxed);
        int written = snprintf(temp_path, temp_capacity, "%s.cbm.tmp.%ld.%u", path,
                               (long)JL_PROCESS_ID(), sequence);
        if (written < 0 || (size_t)written >= temp_capacity) {
            free(temp_path);
            return -1;
        }
        errno = 0;
#ifdef _WIN32
        file = cbm_fopen(temp_path, "wbx");
#else
#ifndef O_NOFOLLOW
        free(temp_path);
        return -1;
#else
        int flags = O_WRONLY | O_CREAT | O_EXCL | O_NOFOLLOW;
#ifdef O_CLOEXEC
        flags |= O_CLOEXEC;
#endif
        int descriptor = open(temp_path, flags, 0600);
        if (descriptor >= 0) {
            file = fdopen(descriptor, "wb");
            if (!file) {
                int saved_error = errno;
                close(descriptor);
                (void)cbm_unlink(temp_path);
                errno = saved_error;
            }
        }
#endif
#endif
        if (file) {
            break;
        }
        if (errno != EEXIST) {
            free(temp_path);
            return -1;
        }
    }