HPUX EnterFile[3]

 Tcl_EnterFile(3)                    Tcl                    Tcl_EnterFile(3)

 Tcl Library Procedures                               Tcl Library Procedures

                                     7.0



 ___________________________________________________________________________

 NAME
      Tcl_EnterFile, Tcl_GetOpenFile, Tcl_FilePermissions -  manipulate  the
      table of open files

 SYNOPSIS
      #include <tcl.h>

      Tcl_EnterFile(interp, file, permissions)

      int
      Tcl_GetOpenFile(interp, string, write, checkUsage, filePtr)

      int
      Tcl_FilePermissions(file)

 ARGUMENTS
      Tcl_Interp   *interp      (in)      Tcl interpreter from which file is
                                          to be accessed.

      FILE         *file        (in)      Handle for file that is to  become
                                          accessible in interp.

      int          permissions  (in)          OR-ed      combination      of
                                          TCL_FILE_READABLE              and
                                          TCL_FILE_WRITABLE;       indicates
                                          whether   file   was   opened  for
                                          reading or writing or both.

      char         *string      (in)      String identifying file,  such  as
                                          stdin or file4.

      int          write        (in)      Non-zero means the  file  will  be
                                          used  for  writing,  zero means it
                                          will be used for reading.

      int          checkUsage   (in)      If non-zero, then an error will be
                                          generated   if   the  file  wasn't
                                          opened for the access indicated by
                                          write.

      FILE         **filePtr    (out)     Points to word in which  to  store
                                          pointer  to FILE structure for the
                                          file given by string.
 ___________________________________________________________________________


 DESCRIPTION



                                    - 1 -        Formatted:  August 11, 1996






 Tcl_EnterFile(3)                    Tcl                    Tcl_EnterFile(3)

 Tcl Library Procedures                               Tcl Library Procedures

                                     7.0



      These procedures  provide  access  to  Tcl's  file  naming  mechanism.
      Tcl_EnterFile enters an open file into Tcl's file table so that it can
      be accessed using Tcl commands like gets, puts, seek, and  close.   It
      returns in interp->result an identifier such as file4 that can be used
      to refer to the file in subsequent  Tcl  commands.   Tcl_EnterFile  is
      typically used to implement new Tcl commands that open sockets, pipes,
      or other  kinds  of  files  not  already  supported  by  the  built-in
      commands.

      Tcl_GetOpenFile takes as  argument  a  file  identifier  of  the  form
      returned  by the open command or Tcl_EnterFile and returns at *filePtr
      a pointer to the FILE structure for  the  file.   The  write  argument
      indicates  whether  the  FILE  pointer  will  be  used  for reading or
      writing.  In some cases, such as a file that connects to a pipeline of
      subprocesses, different FILE pointers will be returned for reading and
      writing.  Tcl_GetOpenFile normally returns TCL_OK.  If an error occurs
      in  Tcl_GetOpenFile  (e.g.  string didn't make any sense or checkUsage
      was set and the file wasn't opened for the access specified by  write)
      then  TCL_ERROR  is  returned and interp->result will contain an error
      message.  If checkUsage is zero and the file  wasn't  opened  for  the
      access  specified by write, then the FILE pointer returned at *filePtr
      may not correspond to write.

      Tcl_FilePermissions returns an OR-ed  combination  of  the  mask  bits
      TCL_FILE_READABLE  and  TCL_FILE_WRITABLE;  these indicate whether the
      given file was opened for reading or writing or both.   If  file  does
      not refer to a file in Tcl's file table then -1 is returned.


 KEYWORDS
      file table, permissions, pipeline, read, write





















                                    - 2 -        Formatted:  August 11, 1996