Content-type: text/html Man page of utime

utime

Section: System Calls (2)
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NAME

utime, utimes - Sets file access and modification times  

SYNOPSIS

#include <sys/time.h>

#include <utime.h>

#include <sys/types.h>

int utime (        const char *path,
       const struct utimbuf *times );

int utimes (        const char *path,
       const struct timeval times[2];

[Digital]  The following definition of the utime() function does not conform to current standards and is supported only for backward compatibility (see standards(5)):

int utime (        const char *path,
       struct utimbuf *times );

int utimes (        const char *path,
       struct timeval times[2];
 

STANDARDS

Interfaces documented on this reference page conform to industry standards as follows:

utime(): POSIX.1, XPG4

utimes(): POSIX.1, XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.  

PARAMETERS

Points to the file. If the final component of the path parameter names a symbolic link, the link will be traversed and pathname resolution will continue. Points to a utimbuf structure for the utime() function, or to an array of timeval structures for the utimes() function.  

DESCRIPTION

The utimes() function sets the access and modification times of the file pointed to by the path parameter to the value of the times parameter. The utimes() function allows time specifications accurate to the microsecond.

The utime() function also sets file access and modification times; however, each time is contained in a single integer and is accurate only to the nearest second.

For utime(), the times parameter is a pointer to a utimbuf structure, defined in the utime.h header file. The first structure member represents the date and time of last access, and the second member represents the date and time of last modification. The times in the utimbuf structure are measured in seconds since the epoch (00:00:00, January 1, 1970, Coordinated Universal Time (CUT)).

For utimes(), the times parameter is an array of timeval structures, as defined in the sys/time.h header file. The first array element represents the date and time of last access, and the second element represents the date and time of last modification. The times in the timeval structure are measured in seconds and microseconds since the epoch, although rounding toward the nearest second may occur.

If the times parameter is null, the access and modification times of the file are set to the current time. If the file is a remote file, the current time at the remote node, rather than the local node, is used. The effective user ID of the process must be the same as the owner of the file, or must have write access to the file or superuser privilege in order to use the call in this manner.

If the times parameter is not null, the access and modification times are set to the values contained in the designated structure, regardless of whether those times correlate with the current time. Only the owner of the file or a user with superuser privilege can use the call this way.

Upon successful completion, the utime() and utimes() functions mark the time of the last file status change, st_ctime, for update.  

RETURN VALUES

Upon successful completion, a value of 0 (zero) is returned. Otherwise, a value of -1 is returned, errno is set to indicate the error, and the file times will not be affected.  

ERRORS

If the utimes() or utime() function fails, errno may be set to one of the following values: Search permission is denied by a component of the path prefix; or the times parameter is null and effective user ID is neither the owner of the file nor has appropriate system privilege, and write access is denied. The path parameter is an invalid address, or (for utimes()) either the path or times parameter is an invalid address. The file is not a regular file. Too many links were encountered in translating path. The length of the path parameter exceeds PATH_MAX or a pathname component is longer than NAME_MAX. The named file does not exist or the path parameter points to an empty string. A component of the path prefix is not a directory. The times parameter is not the null value and the calling process has write access to the file but neither owns the file nor has the appropriate system privilege. The file system that contains the file is mounted read-only. The process' root or current directory is located in a virtual file system that has been unmounted.

The utimes() function can also fail if additional errors occur.  

RELATED INFORMATION

Functions: stat(2)

Standards: standards(5) delim off


 

Index

NAME
SYNOPSIS
STANDARDS
PARAMETERS
DESCRIPTION
RETURN VALUES
ERRORS
RELATED INFORMATION

This document was created by man2html, using the manual pages.
Time: 02:40:13 GMT, October 02, 2010