NAME¶
Tcl_IsSafe, Tcl_MakeSafe, Tcl_CreateSlave, Tcl_GetSlave, 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_CreateSlave(interp, slaveName, isSafe)
Tcl_Interp *
Tcl_GetSlave(interp, slaveName)
Tcl_Interp *
Tcl_GetMaster(interp)
int
Tcl_GetInterpPath(askingInterp, slaveInterp)
int
Tcl_CreateAlias(slaveInterp, slaveCmd, targetInterp, targetCmd,
argc, argv)
int
Tcl_CreateAliasObj(slaveInterp, slaveCmd, targetInterp, targetCmd,
objc, objv)
int
Tcl_GetAlias(interp, slaveCmd, targetInterpPtr, targetCmdPtr,
argcPtr, argvPtr)
int
Tcl_GetAliasObj(interp, slaveCmd, 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 *slaveName (in)
- Name of slave interpreter to create or manipulate.
- int isSafe (in)
- If non-zero, a “safe” slave that is suitable for running
untrusted code is created, otherwise a trusted slave is created.
- Tcl_Interp *slaveInterp (in)
- Interpreter to use for creating the source command for an alias (see
below).
- const char *slaveCmd (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
result field of the interpreter contains an error message.
Tcl_CreateSlave creates a new interpreter as a slave of
interp. It
also creates a slave command named
slaveName in
interp which
allows
interp to manipulate the new slave. If
isSafe is zero,
the command creates a trusted slave in which Tcl code has access to all the
Tcl commands. If it is
1, the command creates a “safe”
slave 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 slave interpreter failed,
NULL is returned.
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 slave interpreter of
interp.
The slave interpreter is identified by
slaveName. If no such slave
interpreter exists,
NULL is returned.
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_GetInterpPath sets the
result field in
askingInterp to
the relative path between
askingInterp and
slaveInterp;
slaveInterp must be a slave of
askingInterp. If the computation
of the relative path succeeds,
TCL_OK is returned, else
TCL_ERROR is returned and the
result field in
askingInterp contains the error message.
Tcl_CreateAlias creates a command named
slaveCmd in
slaveInterp 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
slaveCmd 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
slaveInterp. Note
that there are no restrictions on the ancestry relationship (as created by
Tcl_CreateSlave) between
slaveInterp 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_GetAlias returns information 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
targetNamePtr is non-
NULL it is set to a pointer to the string
containing the name of the target command.
Tcl_GetAliasObj is similar to
Tcl_GetAlias except that it returns
a pointer to a vector of Tcl_Obj structures instead of a vector of strings.
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 in the
result field in
interp. If an exposed
command named
cmdName already exists, the operation returns
TCL_ERROR and leaves an error message in the value result of
interp. If the operation succeeds, it returns
TCL_OK. After
executing this command, attempts to use
cmdName in a call to
Tcl_Eval or with the Tcl
eval command 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 in the value 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 in the value
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 the
result field in
interp contains an
error message. If the operation succeeds, it returns
TCL_OK. After
executing this command, attempts to use
cmdName in a call to
Tcl_Eval or with the Tcl
eval command will fail.
For a description of the Tcl interface to multiple interpreters, see
interp(3tcl).
SEE ALSO¶
interp
KEYWORDS¶
alias, command, exposed commands, hidden commands, interpreter, invoke, master,
slave