Provided by: tcl8.5-doc_8.5.15-2ubuntu1_all bug

NAME

       Tcl_EvalObjEx,   Tcl_EvalFile,   Tcl_EvalObjv,   Tcl_Eval,   Tcl_EvalEx,   Tcl_GlobalEval,
       Tcl_GlobalEvalObj, Tcl_VarEval, Tcl_VarEvalVA - execute Tcl scripts

SYNOPSIS

       #include <tcl.h>

       int
       Tcl_EvalObjEx(interp, objPtr, flags)

       int
       Tcl_EvalFile(interp, fileName)

       int
       Tcl_EvalObjv(interp, objc, objv, flags)

       int
       Tcl_Eval(interp, script)

       int
       Tcl_EvalEx(interp, script, numBytes, flags)

       int
       Tcl_GlobalEval(interp, script)

       int
       Tcl_GlobalEvalObj(interp, objPtr)

       int
       Tcl_VarEval(interp, part, part, ... (char *) NULL)

       int
       Tcl_VarEvalVA(interp, argList)

ARGUMENTS

       Tcl_Interp *interp (in)            Interpreter  in  which  to  execute  the  script.   The
                                          interpreter's  result is modified to hold the result or
                                          error message from the script.

       Tcl_Obj *objPtr (in)               A Tcl object containing the script to execute.

       int flags (in)                     ORed combination of flag bits that  specify  additional
                                          options.    TCL_EVAL_GLOBAL   and  TCL_EVAL_DIRECT  are
                                          currently supported.

       const char *fileName (in)          Name of a file containing a Tcl script.

       int objc (in)                      The number of  objects  in  the  array  pointed  to  by
                                          objPtr;  this  is  also  the  number  of  words  in the
                                          command.

       Tcl_Obj **objv (in)                Points to an array of pointers to objects; each  object
                                          holds  the  value  of  a  single word in the command to
                                          execute.

       int numBytes (in)                  The number of bytes in script, not including  any  null
                                          terminating  character.   If -1, then all characters up
                                          to the first null byte are used.

       const char *script (in)            Points to  first  byte  of  script  to  execute  (null-
                                          terminated and UTF-8).

       char *part (in)                    String forming part of a Tcl script.

       va_list argList (in)               An argument list which must have been initialized using
                                          va_start, and cleared using va_end.
_________________________________________________________________

DESCRIPTION

       The procedures described here are  invoked  to  execute  Tcl  scripts  in  various  forms.
       Tcl_EvalObjEx  is  the  core procedure and is used by many of the others.  It executes the
       commands in the script stored in objPtr until either an error occurs or  the  end  of  the
       script  is  reached.  If this is the first time objPtr has been executed, its commands are
       compiled into bytecode instructions which are then executed.  The bytecodes are  saved  in
       objPtr so that the compilation step can be skipped if the object is evaluated again in the
       future.

       The return value from Tcl_EvalObjEx (and all the other procedures described here) is a Tcl
       completion  code  with  one  of  the  values  TCL_OK, TCL_ERROR, TCL_RETURN, TCL_BREAK, or
       TCL_CONTINUE, or possibly some other  integer  value  originating  in  an  extension.   In
       addition,  a result value or error message is left in interp's result; it can be retrieved
       using Tcl_GetObjResult.

       Tcl_EvalFile reads the file given by fileName and evaluates its contents as a Tcl  script.
       It  returns  the  same information as Tcl_EvalObjEx.  If the file could not be read then a
       Tcl error is returned to describe why the file could not be read.  The eofchar  for  files
       is  “\32” (^Z) for all platforms. If you require a “^Z” in code for string comparison, you
       can use “\032” or “\u001a”, which will be safely substituted by the Tcl  interpreter  into
       “^Z”.

       Tcl_EvalObjv  executes a single pre-parsed command instead of a script.  The objc and objv
       arguments contain the values of the words for the Tcl command, one word in each object  in
       objv.   Tcl_EvalObjv  evaluates  the command and returns a completion code and result just
       like Tcl_EvalObjEx.  The caller of Tcl_EvalObjv has to manage the reference count  of  the
       elements of objv, insuring that the objects are valid until Tcl_EvalObjv returns.

       Tcl_Eval  is similar to Tcl_EvalObjEx except that the script to be executed is supplied as
       a string instead of an object and no compilation occurs.  The string should  be  a  proper
       UTF-8  string  as  converted  by  Tcl_ExternalToUtfDString or Tcl_ExternalToUtf when it is
       known to possibly contain upper ASCII characters whose possible combinations  might  be  a
       UTF-8  special  code.   The  string  is  parsed and executed directly (using Tcl_EvalObjv)
       instead of compiling it and executing the bytecodes.  In situations where it is known that
       the script will never be executed again, Tcl_Eval may be faster than Tcl_EvalObjEx.
        Tcl_Eval  returns  a  completion  code  and  result  just  like Tcl_EvalObjEx.  Note: for
       backward compatibility with versions before Tcl 8.0, Tcl_Eval copies the object result  in
       interp to interp->result (use is deprecated) where it can be accessed directly.
        This makes Tcl_Eval somewhat slower than Tcl_EvalEx, which does not do the copy.

       Tcl_EvalEx is an extended version of Tcl_Eval that takes additional arguments numBytes and
       flags.  For the efficiency reason given above,  Tcl_EvalEx  is  generally  preferred  over
       Tcl_Eval.

       Tcl_GlobalEval  and  Tcl_GlobalEvalObj are older procedures that are now deprecated.  They
       are similar to Tcl_EvalEx and Tcl_EvalObjEx except that the script  is  evaluated  in  the
       global  namespace  and  its variable context consists of global variables only (it ignores
       any Tcl procedures that  are  active).   These  functions  are  equivalent  to  using  the
       TCL_EVAL_GLOBAL flag (see below).

       Tcl_VarEval  takes  any number of string arguments of any length, concatenates them into a
       single string, then calls Tcl_Eval to execute that string as a Tcl  command.   It  returns
       the  result  of  the command and also modifies interp->result in the same way as Tcl_Eval.
       The last argument  to  Tcl_VarEval  must  be  NULL  to  indicate  the  end  of  arguments.
       Tcl_VarEval is now deprecated.

       Tcl_VarEvalVA  is  the same as Tcl_VarEval except that instead of taking a variable number
       of arguments it takes an argument list. Like Tcl_VarEval, Tcl_VarEvalVA is deprecated.

FLAG BITS

       Any ORed combination of the following values  may  be  used  for  the  flags  argument  to
       procedures such as Tcl_EvalObjEx:

       TCL_EVAL_DIRECT        This  flag  is  only  used by Tcl_EvalObjEx; it is ignored by other
                              procedures.  If this flag bit is set, the script is not compiled to
                              bytecodes;   instead   it  is  executed  directly  as  is  done  by
                              Tcl_EvalEx.  The TCL_EVAL_DIRECT flag is useful in situations where
                              the  contents  of an object are going to change immediately, so the
                              bytecodes will not be reused in a future execution.  In this  case,
                              it is faster to execute the script directly.

       TCL_EVAL_GLOBAL        If this flag is set, the script is processed at global level.  This
                              means that it is evaluated in the global namespace and its variable
                              context  consists  of  global  variables  only  (it ignores any Tcl
                              procedures at are active).

MISCELLANEOUS DETAILS

       During the processing of a Tcl command it is legal to make nested calls to evaluate  other
       commands  (this is how procedures and some control structures are implemented).  If a code
       other than TCL_OK is returned from a nested  Tcl_EvalObjEx  invocation,  then  the  caller
       should  normally return immediately, passing that same return code back to its caller, and
       so on until the top-level application is reached.  A few commands, like  for,  will  check
       for  certain  return  codes,  like  TCL_BREAK and TCL_CONTINUE, and process them specially
       without returning.

       Tcl_EvalObjEx keeps track of how many nested Tcl_EvalObjEx invocations are in progress for
       interp.   If a code of TCL_RETURN, TCL_BREAK, or TCL_CONTINUE is about to be returned from
       the topmost Tcl_EvalObjEx invocation for interp, it converts the return code to  TCL_ERROR
       and  sets  interp's  result  to  an  error  message  indicating that the return, break, or
       continue command was invoked  in  an  inappropriate  place.   This  means  that  top-level
       applications  should  never  see  a  return  code  from Tcl_EvalObjEx other then TCL_OK or
       TCL_ERROR.

KEYWORDS

       execute, file, global, object, result, script