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Handling File Attributes
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   When `tar' reads files, this causes them to have the access times
updated.  To have `tar' attempt to set the access times back to what
they were before they were read, use the `--atime-preserve' option.

   Handling of file attributes

`--atime-preserve'
     Preserve access times on files that are read.  This doesn't work
     for files that you don't own, unless you're root, and it doesn't
     interact with incremental dumps nicely (Note: Backups), and it
     can set access or modification times incorrectly if other programs
     access the file while `tar' is running; but it is good enough for
     some purposes.

`-m'
`--touch'
     Do not extract file modified time.

     When this option is used, `tar' leaves the modification times of
     the files it extracts as the time when the files were extracted,
     instead of setting it to the time recorded in the archive.

     This option is meaningless with `--list' (`-t').

`--same-owner'
     Create extracted files with the same ownership they have in the
     archive.

     This is the default behavior for the superuser, so this option is
     meaningful only for non-root users, when `tar' is executed on
     those systems able to give files away.  This is considered as a
     security flaw by many people, at least because it makes quite
     difficult to correctly account users for the disk space they
     occupy.  Also, the `suid' or `sgid' attributes of files are easily
     and silently lost when files are given away.

     When writing an archive, `tar' writes the user id and user name
     separately.  If it can't find a user name (because the user id is
     not in `/etc/passwd'), then it does not write one.  When restoring,
     and doing a `chmod' like when you use `--same-permissions'
     (`--preserve-permissions', `-p'), it tries to look the name (if
     one was written) up in `/etc/passwd'.  If it fails, then it uses
     the user id stored in the archive instead.

`--no-same-owner'
     Do not attempt to restore ownership when extracting.  This is the
     default behavior for ordinary users, so this option has an effect
     only for the superuser.

`--numeric-owner'
     The `--numeric-owner' option allows (ANSI) archives to be written
     without user/group name information or such information to be
     ignored when extracting.  It effectively disables the generation
     and/or use of user/group name information.  This option forces
     extraction using the numeric ids from the archive, ignoring the
     names.

     This is useful in certain circumstances, when restoring a backup
     from an emergency floppy with different passwd/group files for
     example.  It is otherwise impossible to extract files with the
     right ownerships if the password file in use during the extraction
     does not match the one belonging to the filesystem(s) being
     extracted.  This occurs, for example, if you are restoring your
     files after a major crash and had booted from an emergency floppy
     with no password file or put your disk into another machine to do
     the restore.

     The numeric ids are _always_ saved into `tar' archives.  The
     identifying names are added at create time when provided by the
     system, unless `--old-archive' (`-o') is used.  Numeric ids could
     be used when moving archives between a collection of machines using
     a centralized management for attribution of numeric ids to users
     and groups.  This is often made through using the NIS capabilities.

     When making a `tar' file for distribution to other sites, it is
     sometimes cleaner to use a single owner for all files in the
     distribution, and nicer to specify the write permission bits of the
     files as stored in the archive independently of their actual value
     on the file system.  The way to prepare a clean distribution is
     usually to have some Makefile rule creating a directory, copying
     all needed files in that directory, then setting ownership and
     permissions as wanted (there are a lot of possible schemes), and
     only then making a `tar' archive out of this directory, before
     cleaning everything out.  Of course, we could add a lot of options
     to GNU `tar' for fine tuning permissions and ownership.  This is
     not the good way, I think.  GNU `tar' is already crowded with
     options and moreover, the approach just explained gives you a
     great deal of control already.

`-p'
`--same-permissions'
`--preserve-permissions'
     Extract all protection information.

     This option causes `tar' to set the modes (access permissions) of
     extracted files exactly as recorded in the archive.  If this option
     is not used, the current `umask' setting limits the permissions on
     extracted files.

     This option is meaningless with `--list' (`-t').

`--preserve'
     Same as both `--same-permissions' (`--preserve-permissions', `-p')
     and `--same-order' (`--preserve-order', `-s').

     The `--preserve' option has no equivalent short option name.  It
     is equivalent to `--same-permissions' (`--preserve-permissions',
     `-p') plus `--same-order' (`--preserve-order', `-s').