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fd_filestat_set_times

fd_filestat_set_times()

Set timestamp metadata on a file.

Description

The fd_filestat_set_times() function is used to set the timestamp metadata on a file identified by a file descriptor. It allows modifying the last accessed time (st_atim) and last modified time (st_mtim) of the file. The function also provides a bit-vector (fst_flags) to control which times should be set.

In POSIX systems, files have associated timestamp metadata that stores information about the file's access and modification times. The fd_filestat_set_times() function enables applications to update these timestamps. It allows setting the last accessed and last modified times to specific values or using the current time.

Syntax

  ;;; Note: This is similar to `futimens` in POSIX.
  ;;; Adjust the timestamps of an open file or directory.
  (@interface func (export "fd_filestat_set_times")
    (param $fd $fd)
    ;;; The desired values of the data access timestamp.
    (param $atim $timestamp)
    ;;; The desired values of the data modification timestamp.
    (param $mtim $timestamp)
    ;;; A bitmask indicating which timestamps to adjust.
    (param $fst_flags $fstflags)
    (result $error (expected (error $errno)))
  )

Parameters

  • ctx: A mutable reference to the function environment.
  • fd: The file descriptor of the file to set the timestamp metadata.
  • st_atim: The last accessed time to set.
  • st_mtim: The last modified time to set.
  • fst_flags: A bit-vector that controls which times to set.

Return Value

The function returns an Errno value indicating the success or failure of the operation.

Logging

This function has been instrumented with debug-level logging. It will log the following information:

  • %fd: The file descriptor being modified.
  • %st_atim: The last accessed time being set.
  • %st_mtim: The last modified time being set.

Note

The fd_filestat_set_times() function allows setting the timestamp metadata of a file identified by the provided file descriptor. Applications can specify the last accessed and last modified times using the provided parameters. The fst_flags bit-vector is used to control which times should be set.

Please note that if both SET_ATIM and SET_ATIM_NOW flags are set, or if both SET_MTIM and SET_MTIM_NOW flags are set in fst_flags, the function will return Errno::Inval.

fd_filestat_set_sizefd_pread