UTIME(P) UTIME(P)
NAME
utime - set file access and modification times
SYNOPSIS
#include <utime.h>
int utime(const char *path, const struct utimbuf *times);
DESCRIPTION
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, utime() shall mark the time of the last file status change,
st_ctime, to be updated; see <sys/stat.h>.
RETURN VALUE
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.
ERRORS
The utime() function shall fail if:
EACCES Search permission is denied by a component of the path prefix; or the times argu-
ment 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 the path argument exceeds {PATH_MAX} or a pathname component 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 is not a directory.
EPERM The times argument is not a null pointer and the calling process' effective user ID
does not match the owner of the file and the calling process does not have the
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
As a result of encountering a symbolic link in resolution of the path argument, the
length of the substituted pathname string exceeded {PATH_MAX}.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
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 access time on the file. If an applica-
tion intends to leave one of the times of a file unchanged while changing the other, it
should use stat() to retrieve the file's st_atime and st_mtime parameters, set actime and
modtime in the buffer, and change one of them before making the utime() call.
FUTURE DIRECTIONS
None.
SEE ALSO
The Base Definitions volume of IEEE Std 1003.1-2001, <sys/stat.h>, <utime.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
POSIX 2003 UTIME(P)
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