Tcl_GetStringResult man page on OpenMandriva

Man page or keyword search:  
man Server   8135 pages
apropos Keyword Search (all sections)
Output format
OpenMandriva logo
[printable version]

Tcl_SetResult(3)	    Tcl Library Procedures	      Tcl_SetResult(3)

______________________________________________________________________________

NAME
       Tcl_SetObjResult, Tcl_GetObjResult, Tcl_SetResult, Tcl_GetStringResult,
       Tcl_AppendResult, Tcl_AppendResultVA,  Tcl_AppendElement,  Tcl_ResetRe‐
       sult, Tcl_TransferResult, Tcl_FreeResult - manipulate Tcl result

SYNOPSIS
       #include <tcl.h>

       Tcl_SetObjResult(interp, objPtr)

       Tcl_Obj *
       Tcl_GetObjResult(interp)

       Tcl_SetResult(interp, result, freeProc)

       const char *
       Tcl_GetStringResult(interp)

       Tcl_AppendResult(interp, result, result, ... , (char *) NULL)

       Tcl_AppendResultVA(interp, argList)

       Tcl_ResetResult(interp)

       Tcl_TransferResult(sourceInterp, result, targetInterp)		       │

       Tcl_AppendElement(interp, element)

       Tcl_FreeResult(interp)

ARGUMENTS
       Tcl_Interp *interp (out)		       Interpreter  whose result is to
					       be modified or read.

       Tcl_Obj *objPtr (in)		       Tcl value to become result  for
					       interp.

       char *result (in)		       String  value  to become result
					       for interp or to be appended to
					       the existing result.

       const char *element (in)		       String  value  to  append  as a
					       list element  to	 the  existing
					       result of interp.

       Tcl_FreeProc *freeProc (in)	       Address of procedure to call to
					       release storage at  result,  or
					       TCL_STATIC,   TCL_DYNAMIC,   or
					       TCL_VOLATILE.

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

       Tcl_Interp *sourceInterp (in)	       Interpreter that the result and │
					       error  information  should   be │
					       copied from.

       Tcl_Interp *targetInterp (in)	       Interpreter that the result and │
					       error  information  should   be │
					       copied to.

       int result (in)			       If   TCL_OK,   only   copy  the │
					       result. If TCL_ERROR, copy  the │
					       error information as well.
_________________________________________________________________

DESCRIPTION
       The procedures described here are utilities for manipulating the result
       value in a Tcl interpreter.  The interpreter result may be either a Tcl
       value or a string.  For example, Tcl_SetObjResult and Tcl_SetResult set
       the interpreter result to, respectively, a value and a  string.	 Simi‐
       larly,  Tcl_GetObjResult and Tcl_GetStringResult return the interpreter
       result as a value and as a string.   The	 procedures  always  keep  the
       string and value forms of the interpreter result consistent.  For exam‐
       ple, if Tcl_SetObjResult is called to set the result to a  value,  then
       Tcl_GetStringResult is called, it will return the value's string repre‐
       sentation.

       Tcl_SetObjResult arranges for objPtr  to	 be  the  result  for  interp,
       replacing  any  existing	 result.   The	result is left pointing to the
       value referenced by objPtr.  objPtr's reference	count  is  incremented
       since  there  is	 now a new reference to it from interp.	 The reference
       count for any old result value is decremented and the old result	 value
       is freed if no references to it remain.

       Tcl_GetObjResult returns the result for interp as a value.  The value's
       reference count is not incremented; if the caller  needs	 to  retain  a
       long-term  pointer  to  the  value  they should use Tcl_IncrRefCount to
       increment its reference count in order to keep it from being freed  too
       early or accidentally changed.

       Tcl_SetResult  arranges for result to be the result for the current Tcl
       command in interp, replacing any existing result.  The  freeProc	 argu‐
       ment specifies how to manage the storage for the result argument; it is
       discussed in the section THE  TCL_FREEPROC  ARGUMENT  TO	 TCL_SETRESULT
       below.	If  result is NULL, then freeProc is ignored and Tcl_SetResult
       re-initializes interp's result to point to an empty string.

       Tcl_GetStringResult returns the result for interp as a string.  If  the
       result  was  set	 to a value by a Tcl_SetObjResult call, the value form
       will be converted to a string and returned.  If the value's string rep‐
       resentation contains null bytes, this conversion will lose information.
       For this reason, programmers are encouraged to write their code to  use
       the new value API procedures and to call Tcl_GetObjResult instead.

       Tcl_ResetResult	clears	the result for interp and leaves the result in
       its normal empty initialized state.  If the result is a value, its ref‐
       erence  count  is  decremented  and  the	 result is left pointing to an
       unshared value representing an empty string.  If the result is a dynam‐
       ically allocated string, its memory is free*d and the result is left as
       a empty string.	Tcl_ResetResult also clears the error state managed by
       Tcl_AddErrorInfo, Tcl_AddObjErrorInfo, and Tcl_SetErrorCode.

       Tcl_AppendResult	 makes	it easy to build up Tcl results in pieces.  It
       takes each of its result arguments and appends them  in	order  to  the
       current	result	associated  with interp.  If the result is in its ini‐
       tialized empty state (e.g. a command  procedure	was  just  invoked  or
       Tcl_ResetResult was just called), then Tcl_AppendResult sets the result
       to the concatenation of its result arguments.  Tcl_AppendResult may  be
       called  repeatedly  as  additional  pieces  of the result are produced.
       Tcl_AppendResult takes care of all the storage management issues	 asso‐
       ciated  with  managing  interp's	 result,  such	as allocating a larger
       result area if necessary.  It also manages conversion to and  from  the
       result  field of the interp so as to handle backward-compatibility with
       old-style extensions.  Any number of result arguments may be passed  in
       a single call; the last argument in the list must be a NULL pointer.

       Tcl_AppendResultVA  is the same as Tcl_AppendResult except that instead
       of taking a variable number of arguments it takes an argument list.

       Tcl_TransferResult moves a result  from	one  interpreter  to  another, │
       optionally  (dependent  on  the	result	parameter) including the error │
       information dictionary as well. The interpreters must be	 in  the  same │
       thread.	 The  source  interpreter  will	 have its result reset by this │
       operation.

DEPRECATED INTERFACES
   OLD STRING PROCEDURES
       Use of the following procedures (is deprecated  since  they  manipulate
       the  Tcl	 result as a string.  Procedures such as Tcl_SetObjResult that
       manipulate the result as a value can be significantly more efficient.

       Tcl_AppendElement is similar to	Tcl_AppendResult  in  that  it	allows
       results	to  be	built  up in pieces.  However, Tcl_AppendElement takes
       only a single element argument and it appends that argument to the cur‐
       rent result as a proper Tcl list element.  Tcl_AppendElement adds back‐
       slashes or braces if necessary to ensure that interp's  result  can  be
       parsed  as  a  list and that element will be extracted as a single ele‐
       ment.  Under normal conditions,	Tcl_AppendElement  will	 add  a	 space
       character  to  interp's result just before adding the new list element,
       so that the list elements in the result are properly  separated.	  How‐
       ever  if	 the new list element is the first in a list or sub-list (i.e.
       interp's current result is empty, or consists of the  single  character
       “{”, or ends in the characters “ {”) then no space is added.

       Tcl_FreeResult  performs part of the work of Tcl_ResetResult.  It frees
       up  the	memory	associated  with  interp's  result.   It   also	  sets
       interp->freeProc	 to  zero, but does not change interp->result or clear
       error state.  Tcl_FreeResult is most commonly used when a procedure  is
       about to replace one result value with another.

   DIRECT ACCESS TO INTERP->RESULT
       It   used  to  be  legal	 for  programs	to  directly  read  and	 write
       interp->result to manipulate the interpreter result.  The  Tcl  headers
       no  longer  permit  this access by default, and C code still doing this
       must be updated to use supported	 routines  Tcl_GetObjResult,  Tcl_Get‐
       StringResult, Tcl_SetObjResult, and Tcl_SetResult.  As a migration aid,
       access can be restored with the compiler directive
	      #define USE_INTERP_RESULT
       but this is meant only to offer life support to otherwise dead code.

THE TCL_FREEPROC ARGUMENT TO TCL_SETRESULT
       Tcl_SetResult's freeProc argument specifies how the Tcl	system	is  to
       manage  the  storage  for  the  result  argument.   If Tcl_SetResult or
       Tcl_SetObjResult are called at  a  time	when  interp  holds  a	string
       result,	they  do  whatever  is	necessary to dispose of the old string
       result (see the Tcl_Interp manual entry for details on this).

       If freeProc is TCL_STATIC it means that result refers  to  an  area  of
       static storage that is guaranteed not to be modified until at least the
       next call to Tcl_Eval.  If freeProc is TCL_DYNAMIC it means that result
       was  allocated  with a call to Tcl_Alloc and is now the property of the
       Tcl system.  Tcl_SetResult will arrange for the string's storage to  be
       released	 by calling Tcl_Free when it is no longer needed.  If freeProc
       is TCL_VOLATILE it means that result points to an area of  memory  that
       is  likely to be overwritten when Tcl_SetResult returns (e.g. it points
       to something in a stack frame).	In this case Tcl_SetResult will make a
       copy of the string in dynamically allocated storage and arrange for the
       copy to be the result for the current Tcl command.

       If freeProc is not one  of  the	values	TCL_STATIC,  TCL_DYNAMIC,  and
       TCL_VOLATILE,  then  it	is  the address of a procedure that Tcl should
       call to free the string.	 This allows applications to use  non-standard
       storage	allocators.   When  Tcl	 no  longer  needs the storage for the
       string, it will call  freeProc.	FreeProc  should  have	arguments  and
       result that match the type Tcl_FreeProc:

	      typedef void Tcl_FreeProc(
		      char *blockPtr);

       When  freeProc  is  called,  its	 blockPtr  will be set to the value of
       result passed to Tcl_SetResult.

SEE ALSO
       Tcl_AddErrorInfo, Tcl_CreateObjCommand, Tcl_SetErrorCode, Tcl_Interp

KEYWORDS
       append, command, element, list, value,  result,	return	value,	inter‐
       preter

Tcl				      8.0		      Tcl_SetResult(3)
[top]

List of man pages available for OpenMandriva

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net