Function futimens [src]

Prototype

pub fn futimens(fd: fd_t, times: ?*const [2]timespec) FutimensError!void

Parameters

fd: fd_ttimes: ?*const [2]timespec

Possible Errors

AccessDenied

times is NULL, or both nsec values are UTIME_NOW, and either:

the effective user ID of the caller does not match the owner of the file, the caller does not have write access to the file, and the caller is not privileged (Linux: does not have either the CAP_FOWNER or the CAP_DAC_OVERRIDE capability); or,
the file is marked immutable (see chattr(1)).

PermissionDenied

The caller attempted to change one or both timestamps to a value other than the current time, or to change one of the timestamps to the current time while leaving the other timestamp unchanged, (i.e., times is not NULL, neither nsec field is UTIME_NOW, and neither nsec field is UTIME_OMIT) and either:

the caller's effective user ID does not match the owner of file, and the caller is not privileged (Linux: does not have the CAP_FOWNER capability); or,
the file is marked append-only or immutable (see chattr(1)).

ReadOnlyFileSystem

Unexpected UnexpectedError

The Operating System returned an undocumented error code.

This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.

When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.

Source

  pub fn futimens(fd: fd_t, times: ?*const [2]timespec) FutimensError!void {
    if (native_os == .wasi and !builtin.link_libc) {
        // TODO WASI encodes `wasi.fstflags` to signify magic values
        // similar to UTIME_NOW and UTIME_OMIT. Currently, we ignore
        // this here, but we should really handle it somehow.
        const error_code = blk: {
            if (times) |times_arr| {
                const atim = times_arr[0].toTimestamp();
                const mtim = times_arr[1].toTimestamp();
                break :blk wasi.fd_filestat_set_times(fd, atim, mtim, .{
                    .ATIM = true,
                    .MTIM = true,
                });
            }

            break :blk wasi.fd_filestat_set_times(fd, 0, 0, .{
                .ATIM_NOW = true,
                .MTIM_NOW = true,
            });
        };
        switch (error_code) {
            .SUCCESS => return,
            .ACCES => return error.AccessDenied,
            .PERM => return error.PermissionDenied,
            .BADF => unreachable, // always a race condition
            .FAULT => unreachable,
            .INVAL => unreachable,
            .ROFS => return error.ReadOnlyFileSystem,
            else => |err| return unexpectedErrno(err),
        }
    }

    switch (errno(system.futimens(fd, times))) {
        .SUCCESS => return,
        .ACCES => return error.AccessDenied,
        .PERM => return error.PermissionDenied,
        .BADF => unreachable, // always a race condition
        .FAULT => unreachable,
        .INVAL => unreachable,
        .ROFS => return error.ReadOnlyFileSystem,
        else => |err| return unexpectedErrno(err),
    }
}  