Tcl_Access(3)         Tcl Library Procedures        Tcl_Access(3)



_________________________________________________________________

NAME
       Tcl_Access,  Tcl_Stat  -  check file permissions and other
       attributes

SYNOPSIS
       #include 

       int
       Tcl_Access(path, mode)

       int
       Tcl_Stat(path, statPtr)

ARGUMENTS
       char          *path      (in)      Native name of the file
                                          to check the attributes
                                          of.

       int           mode       (in)      Mask consisting of  one
                                          or  more of R_OK, W_OK,
                                          X_OK and  F_OK.   R_OK,
                                          W_OK  and  X_OK request
                                          checking  whether   the
                                          file  exists  and   has
                                          read, write  and   exe-
                                          cute       permissions,
                                          respectively.      F_OK
                                          just  requests checking
                                          for  the  existence  of
                                          the file.

       struct stat   *statPtr   (out)     The structure that con-
                                          tains the result.
_________________________________________________________________


DESCRIPTION
       As of Tcl 8.4,  the  object-based  APIs  Tcl_FSAccess  and
       Tcl_FSStat  should be used in preference to Tcl_Access and
       Tcl_Stat, wherever possible.

       There are two reasons for calling Tcl_Access and  Tcl_Stat
       rather than calling system level functions access and stat
       directly.  First, the Windows implementation of both func-
       tions  fixes some bugs in the system level calls.  Second,
       both Tcl_Access and Tcl_Stat (as well as Tcl_OpenFileChan-
       nelProc)  hook  into  a  linked  list  of functions.  This
       allows the possibility to reroute file access to  alterna-
       tive media or access methods.

       Tcl_Access  checks whether the process would be allowed to
       read, write or test for existence of the  file  (or  other
       file  system object) whose name is pathname.   If pathname
       is a symbolic link on Unix, then permissions of  the  file
       referred by this symbolic link are tested.

       On  success  (all  requested permissions granted), zero is
       returned.  On error (at least one bit in mode asked for  a
       permission that is denied, or some other  error occurred),
       -1 is returned.

       Tcl_Stat fills the stat structure statPtr with information
       about  the  specified  file.   You  do not need any access
       rights to the file to get this information  but  you  need
       search rights to all directories named in the path leading
       to the file.  The stat structure includes  info  regarding
       device, inode (always 0 on Windows), privilege mode, nlink
       (always 1 on Windows), user  id  (always  0  on  Windows),
       group  id  (always  0 on Windows), rdev (same as device on
       Windows), size, last access time, last modification  time,
       and creation time.

       If  path exists, Tcl_Stat returns 0 and the stat structure
       is filled with data.  Otherwise, -1 is  returned,  and  no
       stat info is given.


KEYWORDS
       stat, access




Tcl                            8.1                  Tcl_Access(3)