HPUX SetVar[3]
SetVar in anderen Kapiteln des hpux Handbuch:
Tcl_SetVar(3) Tcl Tcl_SetVar(3)
Tcl Library Procedures Tcl Library Procedures
7.0
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NAME
Tcl_SetVar, Tcl_SetVar2, Tcl_GetVar, Tcl_GetVar2, Tcl_UnsetVar,
Tcl_UnsetVar2 - manipulate Tcl variables
SYNOPSIS
#include <tcl.h>
char *
Tcl_SetVar(interp, varName, newValue, flags)
char *
Tcl_SetVar2(interp, name1, name2, newValue, flags)
char *
Tcl_GetVar(interp, varName, flags)
char *
Tcl_GetVar2(interp, name1, name2, flags)
int
Tcl_UnsetVar(interp, varName, flags)
int
Tcl_UnsetVar2(interp, name1, name2, flags)
ARGUMENTS
Tcl_Interp *interp (in) Interpreter containing variable.
char *varName (in) Name of variable. May refer to a
scalar variable or an element of an
array variable.
char *newValue (in) New value for variable.
int flags (in) OR-ed combination of bits providing
additional information for
operation. See below for valid
values.
char *name1 (in) Name of scalar variable, or name of
array variable if name2 is non-
NULL.
char *name2 (in) If non-NULL, gives name of element
within array and name1 must refer
to an array variable.
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Tcl_SetVar(3) Tcl Tcl_SetVar(3)
Tcl Library Procedures Tcl Library Procedures
7.0
DESCRIPTION
These procedures may be used to create, modify, read, and delete Tcl
variables from C code. Tcl_SetVar and Tcl_SetVar2 will create a new
variable or modify an existing one. Both of these procedures set the
given variable to the value given by newValue, and they return a
pointer to a copy of the variable's new value, which is stored in
Tcl's variable structure. Tcl keeps a private copy of the variable's
value, so the caller may change newValue after these procedures return
without affecting the value of the variable. If an error occurs in
setting the variable (e.g. an array variable is referenced without
giving an index into the array), then NULL is returned.
The name of the variable may be specified in either of two ways. If
Tcl_SetVar is called, the variable name is given as a single string,
varName. If varName contains an open parenthesis and ends with a
close parenthesis, then the value between the parentheses is treated
as an index (which can have any string value) and the characters
before the first open parenthesis are treated as the name of an array
variable. If varName doesn't have parentheses as described above,
then the entire string is treated as the name of a scalar variable.
If Tcl_SetVar2 is called, then the array name and index have been
separated by the caller into two separate strings, name1 and name2
respectively; if name2 is zero it means that a scalar variable is
being referenced.
The flags argument may be used to specify any of several options to
the procedures. It consists of an OR-ed combination of any of the
following bits:
TCL_GLOBAL_ONLY
Under normal circumstances the procedures look up variables at
the current level of procedure call for interp, or at global
level if there is no call active. However, if this bit is set in
flags then the variable is looked up at global level even if
there is a procedure call active.
TCL_LEAVE_ERR_MSG
If an error is returned and this bit is set in flags, then an
error message will be left in interp->result. If this flag bit
isn't set then no error message is left (interp->result will not
be modified).
TCL_APPEND_VALUE
If this bit is set then newValue is appended to the current
value, instead of replacing it. If the variable is currently
undefined, then this bit is ignored.
TCL_LIST_ELEMENT
If this bit is set, then newValue is converted to a valid Tcl
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Tcl_SetVar(3) Tcl Tcl_SetVar(3)
Tcl Library Procedures Tcl Library Procedures
7.0
list element before setting (or appending to) the variable. A
separator space is appended before the new list element unless |
the list element is going to be the first element in a list or |
sublist (i.e. the variable's current value is empty, or contains |
the single character ``{'', or ends in `` }''). |
Tcl_GetVar and Tcl_GetVar2 return the current value of a variable.
The arguments to these procedures are treated in the same way as the
arguments to Tcl_SetVar and Tcl_SetVar2. Under normal circumstances,
the return value is a pointer to the variable's value (which is stored
in Tcl's variable structure and will not change before the next call
to Tcl_SetVar or Tcl_SetVar2). The only bits of flags that are used
are TCL_GLOBAL_ONLY and TCL_LEAVE_ERR_MSG, both of which have the same
meaning as for Tcl_SetVar. If an error occurs in reading the variable
(e.g. the variable doesn't exist or an array element is specified for
a scalar variable), then NULL is returned.
Tcl_UnsetVar and Tcl_UnsetVar2 may be used to remove a variable, so
that future calls to Tcl_GetVar or Tcl_GetVar2 for the variable will
return an error. The arguments to these procedures are treated in the
same way as the arguments to Tcl_GetVar and Tcl_GetVar2. If the |
variable is successfully removed then TCL_OK is returned. If the |
variable cannot be removed because it doesn't exist then TCL_ERROR is |
returned. If an array element is specified, the given element is |
removed but the array remains. If an array name is specified without
an index, then the entire array is removed.
SEE ALSO
Tcl_TraceVar
KEYWORDS
array, interpreter, scalar, set, unset, variable
- 3 - Formatted: August 11, 1996