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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
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UTIME(3P) POSIX Programmer's Manual UTIME(3P)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
utime — set file access and modification times
#include <utime.h>
int utime(const char *path, const struct utimbuf *times);
The utime() function shall set the access and modification times
of the file named by the path argument.
If times is a null pointer, the access and modification times of
the file shall be set to the current time. The effective user ID
of the process shall match the owner of the file, or the process
has write permission to the file or has appropriate privileges, to
use utime() in this manner.
If times is not a null pointer, times shall be interpreted as a
pointer to a utimbuf structure and the access and modification
times shall be set to the values contained in the designated
structure. Only a process with the effective user ID equal to the
user ID of the file or a process with appropriate privileges may
use utime() this way.
The utimbuf structure is defined in the <utime.h> header. The
times in the structure utimbuf are measured in seconds since the
Epoch.
Upon successful completion, the utime() function shall mark the
last file status change timestamp for update; see <sys/stat.h>.
Upon successful completion, 0 shall be returned. Otherwise, -1
shall be returned and errno shall be set to indicate the error,
and the file times shall not be affected.
The utime() function shall fail if:
EACCES Search permission is denied by a component of the path
prefix; or the times argument is a null pointer and the
effective user ID of the process does not match the owner
of the file, the process does not have write permission for
the file, and the process does not have appropriate
privileges.
ELOOP A loop exists in symbolic links encountered during
resolution of the path argument.
ENAMETOOLONG
The length of a component of a pathname is longer than
{NAME_MAX}.
ENOENT A component of path does not name an existing file or path
is an empty string.
ENOTDIR
A component of the path prefix names an existing file that
is neither a directory nor a symbolic link to a directory,
or the path argument contains at least one non-<slash>
character and ends with one or more trailing <slash>
characters and the last pathname component names an
existing file that is neither a directory nor a symbolic
link to a directory.
EPERM The times argument is not a null pointer and the effective
user ID of the calling process does not match the owner of
the file and the calling process does not have appropriate
privileges.
EROFS The file system containing the file is read-only.
The utime() function may fail if:
ELOOP More than {SYMLOOP_MAX} symbolic links were encountered
during resolution of the path argument.
ENAMETOOLONG
The length of a pathname exceeds {PATH_MAX}, or pathname
resolution of a symbolic link produced an intermediate
result with a length that exceeds {PATH_MAX}.
The following sections are informative.
None.
Since the utimbuf structure only contains time_t variables and is
not accurate to fractions of a second, applications should use the
utimensat() function instead of the obsolescent utime() function.
The actime structure member must be present so that an application
may set it, even though an implementation may ignore it and not
change the last data access timestamp on the file. If an
application intends to leave one of the times of a file unchanged
while changing the other, it should use stat() or fstat() to
retrieve the file's st_atim and st_mtim parameters, set actime and
modtime in the buffer, and change one of them before making the
utime() call.
The utime() function may be removed in a future version.
fstat(3p), fstatat(3p), futimens(3p)
The Base Definitions volume of POSIX.1‐2017, sys_stat.h(0p),
utime.h(0p)
Portions of this text are reprinted and reproduced in electronic
form from IEEE Std 1003.1-2017, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The
Open Group Base Specifications Issue 7, 2018 Edition, Copyright
(C) 2018 by the Institute of Electrical and Electronics Engineers,
Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard,
the original IEEE and The Open Group Standard is the referee
document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page
are most likely to have been introduced during the conversion of
the source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2017 UTIME(3P)
Pages that refer to this page: time.h(0p), utime.h(0p), pax(1p), touch(1p), asctime(3p), clock(3p), ctime(3p), difftime(3p), fstatvfs(3p), futimens(3p), gmtime(3p), localtime(3p), mktime(3p), strftime(3p), time(3p)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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