af_crkey(3) [debian man page]

af_files(3)						    Attribute Filesystem (AtFS) 					       af_files(3)

NAME

       af_crkey, af_open, af_close, af_rm, af_establish, af_restore - AtFS file system operations

SYNOPSIS

       #include <stdio.h>
       #include <atfs.h>

       int af_crkey (char *syspath, char *name, char *type, Af_key *aso)

       FILE *af_open (Af_key *aso, char *mode)

       int af_close (FILE *stream)

       int af_rm (Af_key *aso)

       int af_establish (Af_key *aso, char *filename)

       int af_restore (Af_key *aso, Af_key *restoredAso)

DESCRIPTION

       af_crkey creates an object key for a regular UNIX file identified by name, type and system path.  syspath is an either absolute or relative
       directory name. An empty syspath refers to the current directory. By convention, AtFS interprets the filename suffix of a UNIX file as type
       and the filename without suffix as name attribute.  To give an example, the path name

	      /usr/andy/foo.c is split up in /usr/andy (syspath) foo (name) c (type)

       A period as first character in the filename is always considered as part of the name. Hence .cshrc has a name but no type. "." and ".." are
       recognized as names too.  If the named UNIX file does not exist, af_crkey creates an empty file.  The created key remains accessible  until
       it is explicitly given up by af_dropkey (manual page af_retrieve(3)).

       af_open	opens  the  contents of the ASO pointed to by aso and associates a stream with it. A pointer to the FILE structure associated with
       the stream is returned. Mode is a character string that is either "r[+]", "w[+]" or "a[+]". See fopen(3) for further details.  Upon  error,
       af_open	returns a NULL pointer.  Non-busy ASOs can only be opened with mode "r". If a non-busy ASO is opened, it's contents will be placed
       in a temporary UNIX file due to storage of versions as deltas.

       af_close closes a stream previously opened by af_open (see fclose(3)). Temporary files created by af_open, holding the contents of a  saved
       versions are unlinked right after being opened so that they will automatically disappear on closing.

       af_rm  removes  the  specified ASO. The application has to have a lock (see af_lock(3)) set on the ASO that shall be deleted by af_rm. ASOs
       with the state attribute set to accessed or frozen cannot be removed.  If you keep multiple keys of one object (perhaps in different  sets)
       af_rm  invalidates  all keys of the removed object.  As AtFS does not support multiple links to saved ASOs, af_rm on a saved version always
       does a physical removal.

       af_establish establishes the contents of the saved version, pointed to by aso in a file named filename. The resulting file  gets  the  ver-
       sion's modification and access date.

       af_restore  is  used to restore formerly saved derived ASOs into their old file location. It also restores the file modification and access
       date. This function cannot be applied to source objects. af_restore returns the key of the restored version in the buffer restoredAso.

SEE ALSO

       fopen(3), fclose(3), af_retrieve(3), af_lock(3)

DIAGNOSTICS

       Upon error, -1 or a nil pointer (depending on the return type) is returned and af_errno is set to the corresponding error number.

AtFS-1.71						     Fri Jun 25 14:33:07 1993						       af_files(3)

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af_lock(3)						    Attribute Filesystem (AtFS) 						af_lock(3)

NAME

       af_lock, af_unlock, af_testlock - mechanism for reserving update rights in AtFS

SYNOPSIS

       #include <atfs.h>

       Af_user *af_lock (Af_key *aso, Af_user *locker)

       Af_user *af_unlock (Af_key *aso)

       Af_user *af_testlock (Af_key *aso)

DESCRIPTION

       This  manual page describes the interface to the AtFS locking mechanism. Locks are used to avoid conflicting updates to one object history.
       After a user has reserved the update rights, no other user may add new versions to the reserved history.  Reserving the update rights  hap-
       pens  by  locking the most recent version of the history.  As AtFS allows adding new versions to each generation in a history, each genera-
       tion may be locked separately. Reserving update rights for old generations (with generation numbers smaller than the newest generation) are
       performed by locking the most recent version of the corresponding generation.  Removing an ASO (af_rm - manual page af_files(3)) and chang-
       ing an ASO's version number (af_svnum - manual page af_version(3)) also requires a lock on the corresponding ASO.

       af_lock reserves the update permission for the user identified by locker. On  successful  completion,  a  buffer  identical  to	locker	is
       returned, a NULL pointer otherwise.

       af_unlock  cancels  a  formerly established reservation of update rights. Only the owner or the locker of an ASO (identified by the Af_user
       structure that was given to the corresponding call of af_lock) are allowed to do this. On successful completion, af_unlock returns a buffer
       containing the identification of the former locker. This may be empty, if the ASO was not locked.  Upon error, a NULL pointer is returned.

       af_testlock  returns  a	buffer	containing an identification of the current locker of the specified ASO. It returns an empty buffer, if no
       lock is set.

SEE ALSO

       af_version(3), af_files(3)

DIAGNOSTICS

       af_lock and af_unlock return -1 on error and af_errno is set to indicate the error number.

AtFS-1.71						     Fri Jun 25 14:33:11 1993							af_lock(3)

Linux and UNIX Man Pages

af_crkey(3) [debian man page]

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