1UTIME(3P)                  POSIX Programmer's Manual                 UTIME(3P)
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PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
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NAME

12       utime — set file access and modification times
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SYNOPSIS

15       #include <utime.h>
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17       int utime(const char *path, const struct utimbuf *times);
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DESCRIPTION

20       The utime() function shall set the access and modification times of the
21       file named by the path argument.
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23       If  times  is  a null pointer, the access and modification times of the
24       file shall be set to the current time. The effective  user  ID  of  the
25       process  shall  match  the  owner of the file, or the process has write
26       permission to the file or has appropriate privileges, to use utime() in
27       this manner.
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29       If times is not a null pointer, times shall be interpreted as a pointer
30       to a utimbuf structure and the access and modification times  shall  be
31       set to the values contained in the designated structure. Only a process
32       with the effective user ID equal to the  user  ID  of  the  file  or  a
33       process with appropriate privileges may use utime() this way.
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35       The  utimbuf structure is defined in the <utime.h> header. The times in
36       the structure utimbuf are measured in seconds since the Epoch.
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38       Upon successful completion, the utime() function shall  mark  the  last
39       file status change timestamp for update; see <sys/stat.h>.
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RETURN VALUE

42       Upon successful completion, 0 shall be returned. Otherwise, -1 shall be
43       returned and errno shall be set to indicate the  error,  and  the  file
44       times shall not be affected.
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ERRORS

47       The utime() function shall fail if:
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49       EACCES Search  permission  is denied by a component of the path prefix;
50              or the times argument is a null pointer and the  effective  user
51              ID  of  the  process  does  not match the owner of the file, the
52              process does not have write permission for  the  file,  and  the
53              process does not have appropriate privileges.
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55       ELOOP  A loop exists in symbolic links encountered during resolution of
56              the path argument.
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58       ENAMETOOLONG
59              The  length  of  a  component  of  a  pathname  is  longer  than
60              {NAME_MAX}.
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62       ENOENT A component of path does not name an existing file or path is an
63              empty string.
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65       ENOTDIR
66              A component of the path prefix names an existing  file  that  is
67              neither  a  directory nor a symbolic link to a directory, or the
68              path argument contains at least one  non-<slash>  character  and
69              ends  with  one or more trailing <slash> characters and the last
70              pathname component names an existing  file  that  is  neither  a
71              directory nor a symbolic link to a directory.
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73       EPERM  The  times argument is not a null pointer and the effective user
74              ID of the calling process does not match the owner of  the  file
75              and the calling process does not have appropriate privileges.
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77       EROFS  The file system containing the file is read-only.
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79       The utime() function may fail if:
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81       ELOOP  More  than  {SYMLOOP_MAX} symbolic links were encountered during
82              resolution of the path argument.
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84       ENAMETOOLONG
85              The length of a pathname exceeds {PATH_MAX}, or pathname resolu‐
86              tion  of  a symbolic link produced an intermediate result with a
87              length that exceeds {PATH_MAX}.
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89       The following sections are informative.
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EXAMPLES

92       None.
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APPLICATION USAGE

95       Since the utimbuf structure only contains time_t variables and  is  not
96       accurate  to fractions of a second, applications should use the utimen‐
97       sat() function instead of the obsolescent utime() function.
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RATIONALE

100       The actime structure member must be present so that an application  may
101       set  it, even though an implementation may ignore it and not change the
102       last data access timestamp on the file. If an  application  intends  to
103       leave one of the times of a file unchanged while changing the other, it
104       should use stat() or fstat() to retrieve the file's st_atim and st_mtim
105       parameters,  set  actime  and  modtime in the buffer, and change one of
106       them before making the utime() call.
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FUTURE DIRECTIONS

109       The utime() function may be removed in a future version.
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SEE ALSO

112       fstat(), fstatat(), futimens()
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114       The Base Definitions volume of POSIX.1‐2017, <sys_stat.h>, <utime.h>
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117       Portions of this text are reprinted and reproduced in  electronic  form
118       from  IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
119       table Operating System Interface (POSIX), The Open Group Base  Specifi‐
120       cations  Issue  7, 2018 Edition, Copyright (C) 2018 by the Institute of
121       Electrical and Electronics Engineers, Inc and The Open Group.   In  the
122       event of any discrepancy between this version and the original IEEE and
123       The Open Group Standard, the original IEEE and The Open Group  Standard
124       is  the  referee document. The original Standard can be obtained online
125       at http://www.opengroup.org/unix/online.html .
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127       Any typographical or formatting errors that appear  in  this  page  are
128       most likely to have been introduced during the conversion of the source
129       files to man page format. To report such errors,  see  https://www.ker
130       nel.org/doc/man-pages/reporting_bugs.html .
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134IEEE/The Open Group                  2017                            UTIME(3P)
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