man-pages/man2/futimesat.2

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.TH FUTIMESAT 2 2021-08-27 "Linux" "Linux Programmer's Manual"
.SH NAME
futimesat \- change timestamps of a file relative to a \
directory file descriptor
.SH SYNOPSIS
.nf
.BR "#include <fcntl.h>" " /* Definition of " AT_* " constants */"
.B #include <sys/time.h>
.PP
.BI "int futimesat(int " dirfd ", const char *" pathname ,
.BI " const struct timeval " times [2]);
.fi
.PP
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.PP
.BR futimesat ():
.nf
_GNU_SOURCE
.fi
.SH DESCRIPTION
This system call is obsolete.
Use
.BR utimensat (2)
instead.
.PP
The
.BR futimesat ()
system call operates in exactly the same way as
.BR utimes (2),
except for the differences described in this manual page.
.PP
If the pathname given in
.I pathname
is relative, then it is interpreted relative to the directory
referred to by the file descriptor
.I dirfd
(rather than relative to the current working directory of
the calling process, as is done by
.BR utimes (2)
for a relative pathname).
.PP
If
.I pathname
is relative and
.I dirfd
is the special value
.BR AT_FDCWD ,
then
.I pathname
is interpreted relative to the current working
directory of the calling process (like
.BR utimes (2)).
.PP
If
.I pathname
is absolute, then
.I dirfd
is ignored.
(See
.BR openat (2)
for an explanation of why the
.I dirfd
argument is useful.)
.SH RETURN VALUE
On success,
.BR futimesat ()
returns a 0.
On error, \-1 is returned and
.I errno
is set to indicate the error.
.SH ERRORS
The same errors that occur for
.BR utimes (2)
can also occur for
.BR futimesat ().
The following additional errors can occur for
.BR futimesat ():
.TP
.B EBADF
.I pathname
is relative but
.I dirfd
is neither
.B AT_FDCWD
nor a valid file descriptor.
.TP
.B ENOTDIR
.I pathname
is relative and
.I dirfd
is a file descriptor referring to a file other than a directory.
.SH VERSIONS
.BR futimesat ()
was added to Linux in kernel 2.6.16;
library support was added to glibc in version 2.4.
.SH CONFORMING TO
This system call is nonstandard.
It was implemented from a specification that was proposed for POSIX.1,
but that specification was replaced by the one for
.BR utimensat (2).
.PP
A similar system call exists on Solaris.
.SH NOTES
.SS Glibc notes
If
.I pathname
is NULL, then the glibc
.BR futimesat ()
wrapper function updates the times for the file referred to by
.IR dirfd .
.\" The Solaris futimesat() also has this strangeness.
.SH SEE ALSO
.BR stat (2),
.BR utimensat (2),
.BR utimes (2),
.BR futimes (3),
.BR path_resolution (7)