Tcl_CreateAlias(3) Tcl Library Procedures Tcl_CreateAlias(3) ______________________________________________________________________________
NAME
Tcl_IsSafe, Tcl_MakeSafe, Tcl_CreateChild, Tcl_CreateSlave,
Tcl_GetChild, Tcl_GetSlave, Tcl_GetParent, Tcl_GetMaster,
Tcl_GetInterpPath, Tcl_CreateAlias, Tcl_CreateAliasObj, Tcl_GetAlias,
Tcl_GetAliasObj, Tcl_ExposeCommand, Tcl_HideCommand - manage multiple
Tcl interpreters, aliases and hidden commands
SYNOPSIS
#include <tcl.h>
int
Tcl_IsSafe(interp)
int
Tcl_MakeSafe(interp)
Tcl_Interp * |
Tcl_CreateChild(interp, name, isSafe) |
Tcl_Interp *
Tcl_CreateSlave(interp, name, isSafe)
Tcl_Interp * |
Tcl_GetChild(interp, name) |
Tcl_Interp *
Tcl_GetSlave(interp, name)
Tcl_Interp * |
Tcl_GetParent(interp) |
Tcl_Interp *
Tcl_GetMaster(interp)
int
Tcl_GetInterpPath(interp, childInterp)
int
Tcl_CreateAlias(childInterp, childCmd, targetInterp, targetCmd,
argc, argv)
int
Tcl_CreateAliasObj(childInterp, childCmd, targetInterp, targetCmd,
objc, objv)
int
Tcl_GetAlias(interp, childCmd, targetInterpPtr, targetCmdPtr,
argcPtr, argvPtr)
int
Tcl_GetAliasObj(interp, childCmd, targetInterpPtr, targetCmdPtr,
objcPtr, objvPtr)
int
Tcl_ExposeCommand(interp, hiddenCmdName, cmdName)
int
Tcl_HideCommand(interp, cmdName, hiddenCmdName)
ARGUMENTS
Tcl_Interp *interp (in) Interpreter in which
to execute the
specified command.
const char *name (in) Name of child
interpreter to create
or manipulate.
int isSafe (in) If non-zero, a "safe"
child that is
suitable for running
untrusted code is
created, otherwise a
trusted child is
created.
Tcl_Interp *childInterp (in) Interpreter to use
for creating the
source command for an
alias (see below).
const char *childCmd (in) Name of source
command for alias.
Tcl_Interp *targetInterp (in) Interpreter that
contains the target
command for an alias.
const char *targetCmd (in) Name of target
command for alias in
targetInterp.
int argc (in) Count of additional
arguments to pass to
the alias command.
const char *const *argv (in) Vector of strings,
the additional
arguments to pass to
the alias command.
This storage is owned
by the caller.
int objc (in) Count of additional
value arguments to
pass to the aliased
command.
Tcl_Obj **objv (in) Vector of Tcl_Obj
structures, the
additional value
arguments to pass to
the aliased command.
This storage is owned
by the caller.
Tcl_Interp **targetInterpPtr (in) Pointer to location
to store the address
of the interpreter
where a target
command is defined
for an alias.
const char **targetCmdPtr (out) Pointer to location
to store the address
of the name of the
target command for an
alias.
int *argcPtr (out) Pointer to location
to store count of
additional arguments
to be passed to the
alias. The location
is in storage owned
by the caller.
const char ***argvPtr (out) Pointer to location
to store a vector of
strings, the
additional arguments
to pass to an alias.
The location is in
storage owned by the
caller, the vector of
strings is owned by
the called function.
int *objcPtr (out) Pointer to location
to store count of
additional value
arguments to be
passed to the alias.
The location is in
storage owned by the
caller.
Tcl_Obj ***objvPtr (out) Pointer to location
to store a vector of
Tcl_Obj structures,
the additional
arguments to pass to
an alias command. The
location is in
storage owned by the
caller, the vector of
Tcl_Obj structures is
owned by the called
function.
const char *cmdName (in) Name of an exposed
command to hide or
create.
const char *hiddenCmdName (in) Name under which a
hidden command is
stored and with which
it can be exposed or
invoked.
______________________________________________________________________________
DESCRIPTION
These procedures are intended for access to the multiple interpreter
facility from inside C programs. They enable managing multiple
interpreters in a hierarchical relationship, and the management of
aliases, commands that when invoked in one interpreter execute a
command in another interpreter. The return value for those procedures
that return an int is either TCL_OK or TCL_ERROR. If TCL_ERROR is
returned then the interpreter's result contains an error message.
Tcl_CreateSlave creates a new interpreter as a child of interp. It
also creates a child command named childName in interp which allows
interp to manipulate the new child. If isSafe is zero, the command
creates a trusted child in which Tcl code has access to all the Tcl
commands. If it is 1, the command creates a "safe" child in which Tcl
code has access only to set of Tcl commands defined as "Safe Tcl"; see
the manual entry for the Tcl interp command for details. If the
creation of the new child interpreter failed, NULL is returned.
Tcl_CreateChild is a synonym for Tcl_CreateSlave. |
Tcl_IsSafe returns 1 if interp is "safe" (was created with the
TCL_SAFE_INTERPRETER flag specified), 0 otherwise.
Tcl_MakeSafe marks interp as "safe", so that future calls to Tcl_IsSafe
will return 1. It also removes all known potentially-unsafe core
functionality (both commands and variables) from interp. However, it
cannot know what parts of an extension or application are safe and does
not make any attempt to remove those parts, so safety is not guaranteed
after calling Tcl_MakeSafe. Callers will want to take care with their
use of Tcl_MakeSafe to avoid false claims of safety. For many
situations, Tcl_CreateSlave may be a better choice, since it creates
interpreters in a known-safe state.
Tcl_GetSlave returns a pointer to a child interpreter of interp. The
child interpreter is identified by childName. If no such child
interpreter exists, NULL is returned.
Tcl_GetChild is a synonym for Tcl_GetSlave. |
Tcl_GetMaster returns a pointer to the master interpreter of interp. If
interp has no master (it is a top-level interpreter) then NULL is
returned.
Tcl_GetParent is a synonym for Tcl_GetMaster. |
Tcl_GetInterpPath stores in the result of interp the relative path
between interp and childInterp; childInterp must be a child of interp.
If the computation of the relative path succeeds, TCL_OK is returned,
else TCL_ERROR is returned and an error message is stored as the result
of interp.
Tcl_CreateAlias creates a command named childCmd in childInterp that
when invoked, will cause the command targetCmd to be invoked in
targetInterp. The arguments specified by the strings contained in argv
are always prepended to any arguments supplied in the invocation of
childCmd and passed to targetCmd. This operation returns TCL_OK if it
succeeds, or TCL_ERROR if it fails; in that case, an error message is
left in the value result of childInterp. Note that there are no
restrictions on the ancestry relationship (as created by
Tcl_CreateSlave) between childInterp and targetInterp. Any two
interpreters can be used, without any restrictions on how they are
related.
Tcl_CreateAliasObj is similar to Tcl_CreateAlias except that it takes a
vector of values to pass as additional arguments instead of a vector of
strings.
Tcl_GetAliasObj returns information in the form of a pointer to a
vector of Tcl_Obj structures about an alias aliasName in interp. Any of
the result fields can be NULL, in which case the corresponding datum is
not returned. If a result field is non-NULL, the address indicated is
set to the corresponding datum. For example, if targetCmdPtr is
non-NULL it is set to a pointer to the string containing the name of
the target command.
Tcl_GetAlias is similar to Tcl_GetAliasObj except that it returns a
pointer to a vector of string instead of a vector of Tcl_Obj
structures. Tcl_GetAlias is deprecated.
Tcl_ExposeCommand moves the command named hiddenCmdName from the set of
hidden commands to the set of exposed commands, putting it under the
name cmdName. HiddenCmdName must be the name of an existing hidden
command, or the operation will return TCL_ERROR and leave an error
message as the result of interp. If an exposed command named cmdName
already exists, the operation returns TCL_ERROR and leaves an error
message as the result of interp. If the operation succeeds, it returns
TCL_OK. After executing this command, attempts to use cmdName in any
script evaluation mechanism will again succeed.
Tcl_HideCommand moves the command named cmdName from the set of exposed
commands to the set of hidden commands, under the name hiddenCmdName.
CmdName must be the name of an existing exposed command, or the
operation will return TCL_ERROR and leave an error message as the
result of interp. Currently both cmdName and hiddenCmdName must not
contain namespace qualifiers, or the operation will return TCL_ERROR
and leave an error message as the result of interp. The CmdName will
be looked up in the global namespace, and not relative to the current
namespace, even if the current namespace is not the global one. If a
hidden command whose name is hiddenCmdName already exists, the
operation also returns TCL_ERROR and an error message is left as the
result of interp. If the operation succeeds, it returns TCL_OK. After
executing this command, attempts to use cmdName in any script
evaluation mechanism will fail.
For a description of the Tcl interface to multiple interpreters, see
interp(n).
SEE ALSO
interp(n)
KEYWORDS
alias, command, exposed commands, hidden commands, interpreter, invoke,
parent, child
Tcl 7.6 Tcl_CreateAlias(3)
tcl 8.6.15 - Generated Tue Dec 3 14:40:17 CST 2024