Tcl_PkgRequire(3)     Tcl Library Procedures    Tcl_PkgRequire(3)



_________________________________________________________________

NAME
       Tcl_PkgRequire, Tcl_PkgRequireEx, Tcl_PkgPresent, Tcl_Pkg-
       PresentEx, Tcl_PkgProvide, Tcl_PkgProvideEx - package ver-
       sion control

SYNOPSIS
       #include 

       CONST char *
       Tcl_PkgRequire(interp, name, version, exact)

       CONST char *
       Tcl_PkgRequireEx(interp, name, version, exact, clientDataPtr)

       CONST char *
       Tcl_PkgPresent(interp, name, version, exact)

       CONST char *
       Tcl_PkgPresentEx(interp, name, version, exact, clientDataPtr)

       int
       Tcl_PkgProvide(interp, name, version)

       int
       Tcl_PkgProvideEx(interp, name, version, clientData)

ARGUMENTS
       Tcl_Interp   *interp         (in)      Interpreter   where
                                              package  is  needed
                                              or available.

       CONST char   *name           (in)      Name of package.

       CONST char   *version        (in)      A   version  string
                                              consisting  of  one
                                              or   more   decimal
                                              numbers   separated
                                              by dots.

       int          exact           (in)      Non-zero means that
                                              only the particular
                                              version   specified
                                              by    version    is
                                              acceptable.    Zero
                                              means  that   newer
                                              versions  than ver-
                                              sion    are    also
                                              acceptable  as long
                                              as  they  have  the
                                              same  major version
                                              number as  version.

       ClientData   clientData      (in)      Arbitrary  value to
                                              be associated  with
                                              the package.

       ClientData   *clientDataPtr  (out)     Pointer to place to
                                              store   the   value
                                              associated with the
                                              matching   package.
                                              It  is only changed
                                              if the  pointer  is
                                              not  NULL  and  the
                                              function  completed
                                              successfully.
_________________________________________________________________


DESCRIPTION
       These procedures provide C-level interfaces to Tcl's pack-
       age and version management facilities.

       Tcl_PkgRequire is equivalent to the package  require  com-
       mand,  Tcl_PkgPresent is equivalent to the package present
       command, and Tcl_PkgProvide is equivalent to  the  package
       provide command.

       See  the documentation for the Tcl commands for details on
       what these procedures do.

       If Tcl_PkgPresent or Tcl_PkgRequire complete  successfully
       they  return  a pointer to the version string for the ver-
       sion of the package that is provided  in  the  interpreter
       (which  may be different than version); if an error occurs
       they return NULL and leave an error message in the  inter-
       preter's result.

       Tcl_PkgProvide  returns  TCL_OK  if  it completes success-
       fully; if an error occurs it returns TCL_ERROR and  leaves
       an error message in the interpreter's result.

       Tcl_PkgProvideEx,  Tcl_PkgPresentEx  and  Tcl_PkgRequireEx
       allow the setting and retrieving of the client data  asso-
       ciated  with  the  package. In all other respects they are
       equivalent to the matching functions.


KEYWORDS
       package, present, provide, require, version



Tcl                            7.5              Tcl_PkgRequire(3)