Tcl_PkgRequire(3)

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NAME

       Tcl_PkgRequire,   Tcl_PkgRequireEx,  Tcl_PkgPresent,  Tcl_PkgPresentEx,
       Tcl_PkgProvide, Tcl_PkgProvideEx - package version control

SYNOPSIS

       #include <tcl.h>

       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 sep-
                                              arated by dots.

       int          exact           (in)      Non-zero  means  that  only  the
                                              particular version specified  by
                                              version   is  acceptable.   Zero
                                              means that newer  versions  than
                                              version  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 match-
                                              ing package. It is only  changed
                                              if  the  pointer is not NULL and
                                              the function completed  success-
                                              fully.
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DESCRIPTION

       These  procedures  provide C-level interfaces to Tcl's package and ver-
       sion management facilities.

       Tcl_PkgRequire is equivalent to the package require command,  Tcl_PkgP-
       resent 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 version 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
       interpreter's result.

       Tcl_PkgProvide returns TCL_OK if it completes successfully; if an error
       occurs it returns TCL_ERROR and leaves an error message in  the  inter-
       preter's result.

       Tcl_PkgProvideEx,  Tcl_PkgPresentEx and Tcl_PkgRequireEx allow the set-
       ting and retrieving of the client data associated 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)