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utime(2) [debian man page]

UTIME(2)						     Linux Programmer's Manual							  UTIME(2)

NAME
utime, utimes - change file last access and modification times SYNOPSIS
#include <sys/types.h> #include <utime.h> int utime(const char *filename, const struct utimbuf *times); #include <sys/time.h> int utimes(const char *filename, const struct timeval times[2]); DESCRIPTION
The utime() system call changes the access and modification times of the inode specified by filename to the actime and modtime fields of times respectively. If times is NULL, then the access and modification times of the file are set to the current time. Changing timestamps is permitted when: either the process has appropriate privileges, or the effective user ID equals the user ID of the file, or times is NULL and the process has write permission for the file. The utimbuf structure is: struct utimbuf { time_t actime; /* access time */ time_t modtime; /* modification time */ }; The utime() system call allows specification of timestamps with a resolution of 1 second. The utimes() system call is similar, but the times argument refers to an array rather than a structure. The elements of this array are timeval structures, which allow a precision of 1 microsecond for specifying timestamps. The timeval structure is: struct timeval { long tv_sec; /* seconds */ long tv_usec; /* microseconds */ }; times[0] specifies the new access time, and times[1] specifies the new modification time. If times is NULL, then analogously to utime(), the access and modification times of the file are set to the current time. RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is set appropriately. ERRORS
EACCES Search permission is denied for one of the directories in the path prefix of path (see also path_resolution(7)). EACCES times is NULL, the caller's effective user ID does not match the owner of the file, the caller does not have write access to the file, and the caller is not privileged (Linux: does not have either the CAP_DAC_OVERRIDE or the CAP_FOWNER capability). ENOENT filename does not exist. EPERM times is not NULL, the caller's effective UID does not match the owner of the file, and the caller is not privileged (Linux: does not have the CAP_FOWNER capability). EROFS path resides on a read-only file system. CONFORMING TO
utime(): SVr4, POSIX.1-2001. POSIX.1-2008 marks utime() as obsolete. utimes(): 4.3BSD, POSIX.1-2001. NOTES
Linux does not allow changing the timestamps on an immutable file, or setting the timestamps to something other than the current time on an append-only file. In libc4 and libc5, utimes() is just a wrapper for utime() and hence does not allow a subsecond resolution. SEE ALSO
chattr(1), futimesat(2), stat(2), utimensat(2), futimens(3), futimes(3) COLOPHON
This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2008-08-06 UTIME(2)

Check Out this Related Man Page

UTIME(3)						   BSD Library Functions Manual 						  UTIME(3)

NAME
utime -- set file times LIBRARY
Standard C Library (libc, -lc) SYNOPSIS
#include <utime.h> int utime(const char *file, const struct utimbuf *timep); DESCRIPTION
This interface is obsoleted by utimes(2). The utime() function sets the access and modification times of the named file. If timep is NULL, the access and modification times are set to the current time. The calling process must be the owner of the file or have permission to write the file. If timep is non-NULL, time is assumed to be a pointer to a utimbuf structure, as defined in <utime.h>: struct utimbuf { time_t actime; /* Access time */ time_t modtime; /* Modification time */ }; The access time is set to the value of the actime member, and the modification time is set to the value of the modtime member. The times are measured in seconds since 0 hours, 0 minutes, 0 seconds, January 1, 1970 Coordinated Universal Time (UTC). The calling process must be the owner of the file or be the super-user. In either case, the inode-change-time of the file is set to the current time. RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error. ERRORS
utime() will fail if: [EACCES] Search permission is denied for a component of the path prefix; or the times argument is NULL and the effective user ID of the process does not match the owner of the file, and is not the super-user, and write access is denied. [EFAULT] file or times points outside the process's allocated address space. [EINVAL] The pathname contains a character with the high-order bit set. [EIO] An I/O error occurred while reading or writing the affected inode. [ELOOP] Too many symbolic links were encountered in translating the pathname. [ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters. [ENOENT] The named file does not exist. [ENOTDIR] A component of the path prefix is not a directory. [EPERM] The times argument is not NULL and the calling process's effective user ID does not match the owner of the file and is not the super-user. [EROFS] The file system containing the file is mounted read-only. SEE ALSO
stat(2), utimes(2) STANDARDS
The utime() function conforms to ISO/IEC 9945-1:1990 (``POSIX.1''). It was however marked as legacy in the IEEE Std 1003.1-2008 (``POSIX.1'') revision of the standard. HISTORY
A utime() function appeared in Version 7 AT&T UNIX. BSD
April 29, 2010 BSD

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