Is there anyway to modify stat information like mtime or ctime manually in Python or any language at all?
Question:
I am trying the following code:
os.stat(path_name)[stat.ST_CTIME] = ctime
However, this gives the following error:
exceptions.TypeError: 'posix.stat_result' object does not support item assignment
Is there anyway to modify ctime?
Thanks!
Answers:
There is no direct way to set change time, it gets updated whenever inode information changes, like ownership, link count, mode, etc..
Try setting the mode to the already set mode:
os.chmod(path_name, os.stat(path_name)[stat.ST_MODE])
os.utime(filename, timetuple) can be used to set the atime and mtime of a file. As far as I know there is no way to modify the ctime from userland without resorting to hacks such as playing with the clock or direct edition of the filesystem (which I really do not recommend), and this is true for any programming language (Python, Perl, C, C++…) : it’s internal OS stuff, and you don’t want to touch it.
See for example in the documentation of the touch command (http://www.delorie.com/gnu/docs/fileutils/fileutils_54.html):
Although touch provides options for
changing two of the times — the times
of last access and modification — of
a file, there is actually a third one
as well: the inode change time. This
is often referred to as a file’s
ctime. The inode change time
represents the time when the file’s
meta-information last changed. One
common example of this is when the
permissions of a file change. Changing
the permissions doesn’t access the
file, so the atime doesn’t change, nor
does it modify the file, so the mtime
doesn’t change. Yet, something about
the file itself has changed, and this
must be noted somewhere. This is the
job of the ctime field. This is
necessary, so that, for example, a
backup program can make a fresh copy
of the file, including the new
permissions value. Another operation
that modifies a file’s ctime without
affecting the others is renaming. In
any case, it is not possible, in
normal operations, for a user to
change the ctime field to a
user-specified value.
GNU stroke implements the change-system-time trick to change ctime of a file. If that’s what you want, GNU stroke does it for you: http://stroke.sourceforge.net/.
Ran into this lately, this is how I ended up doing it:
def _update_ctime(filename, cdatetime):
args = [
'sudo',
'touch',
'-d', str(cdatetime)[:19],
filename,
]
proc = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
if proc.returncode != 0: print('=> Error changing time on file {}'.format(cdatetime))
Not error proof (depending on locales, etc, but can be improved…
I am trying the following code:
os.stat(path_name)[stat.ST_CTIME] = ctime
However, this gives the following error:
exceptions.TypeError: 'posix.stat_result' object does not support item assignment
Is there anyway to modify ctime?
Thanks!
There is no direct way to set change time, it gets updated whenever inode information changes, like ownership, link count, mode, etc..
Try setting the mode to the already set mode:
os.chmod(path_name, os.stat(path_name)[stat.ST_MODE])
os.utime(filename, timetuple) can be used to set the atime and mtime of a file. As far as I know there is no way to modify the ctime from userland without resorting to hacks such as playing with the clock or direct edition of the filesystem (which I really do not recommend), and this is true for any programming language (Python, Perl, C, C++…) : it’s internal OS stuff, and you don’t want to touch it.
See for example in the documentation of the touch command (http://www.delorie.com/gnu/docs/fileutils/fileutils_54.html):
Although touch provides options for
changing two of the times — the times
of last access and modification — of
a file, there is actually a third one
as well: the inode change time. This
is often referred to as a file’s
ctime. The inode change time
represents the time when the file’s
meta-information last changed. One
common example of this is when the
permissions of a file change. Changing
the permissions doesn’t access the
file, so the atime doesn’t change, nor
does it modify the file, so the mtime
doesn’t change. Yet, something about
the file itself has changed, and this
must be noted somewhere. This is the
job of the ctime field. This is
necessary, so that, for example, a
backup program can make a fresh copy
of the file, including the new
permissions value. Another operation
that modifies a file’s ctime without
affecting the others is renaming. In
any case, it is not possible, in
normal operations, for a user to
change the ctime field to a
user-specified value.
GNU stroke implements the change-system-time trick to change ctime of a file. If that’s what you want, GNU stroke does it for you: http://stroke.sourceforge.net/.
Ran into this lately, this is how I ended up doing it:
def _update_ctime(filename, cdatetime):
args = [
'sudo',
'touch',
'-d', str(cdatetime)[:19],
filename,
]
proc = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
if proc.returncode != 0: print('=> Error changing time on file {}'.format(cdatetime))
Not error proof (depending on locales, etc, but can be improved…