NAME

       Tcl_PkgRequire,  Tcl_PkgRequireEx,  Tcl_PkgRequireProc, 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)

       int
       Tcl_PkgRequireProc(interp, name, objc, objv, 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 specification string as described for package require.

       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.

       const void *clientData (in)       Arbitrary value to be associated with the package.

       void *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.  The  storage can be any pointer type with the
                                         same size as a void pointer.

       Tcl_Size objc (in)                Number of requirements.

       Tcl_Obj* objv[] (in)              Array of requirements.
________________________________________________________________________________________________________________

DESCRIPTION

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

       Tcl_PkgRequire is equivalent to the package require command, 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  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 interpreter's result.

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

       Tcl_PkgRequireProc is the form of package require handling multiple requirements.  The  other  forms  are
       present for backward compatibility and translate their invocations to this form.

REFERENCE COUNT MANAGEMENT

       The  requirements  values given (in the objv argument) to Tcl_PkgRequireProc must have non-zero reference
       counts.

KEYWORDS

       package, present, provide, require, version

SEE ALSO

       package(3tcl), Tcl_StaticLibrary(3tcl)

Tcl                                                    7.5                                  Tcl_PkgRequire(3tcl)