Tcl_ExprString man page on UnixWare

Man page or keyword search:  
man Server   3616 pages
apropos Keyword Search (all sections)
Output format
UnixWare logo
[printable version]

Tcl_ExprLong(3)		    Tcl Library Procedures	       Tcl_ExprLong(3)

______________________________________________________________________________

NAME
       Tcl_ExprLong,  Tcl_ExprDouble, Tcl_ExprBoolean, Tcl_ExprString - evalu‐
       ate an expression

SYNOPSIS
       #include <tcl.h>

       int
       Tcl_ExprLong(interp, string, longPtr)

       int
       Tcl_ExprDouble(interp, string, doublePtr)

       int
       Tcl_ExprBoolean(interp, string, booleanPtr)

       int
       Tcl_ExprString(interp, string)

ARGUMENTS
       Tcl_Interp   *interp	  (in)	    Interpreter in  whose  context  to
					    evaluate string or objPtr.

       char	    *string	  (in)	    Expression	to be evaluated.  Must
					    be in writable memory (the expres‐
					    sion  parser makes temporary modi‐
					    fications  to  the	string	during
					    parsing,  which  it	 undoes before
					    returning).

       long	    *longPtr	  (out)	    Pointer to location	 in  which  to
					    store  the	integer	 value	of the
					    expression.

       int	    *doublePtr	  (out)	    Pointer to location	 in  which  to
					    store  the floating-point value of
					    the expression.

       int	    *booleanPtr	  (out)	    Pointer to location	 in  which  to
					    store the 0/1 boolean value of the
					    expression.
_________________________________________________________________

DESCRIPTION
       These four procedures all evaluate the expression given by  the	string
       argument	 and  return  the  result in one of four different forms.  The
       expression can have any of the forms  accepted  by  the	expr  command.
       Note  that  these  procedures have been largely replaced by the object-
       based   procedures   Tcl_ExprLongObj,   Tcl_ExprDoubleObj,    Tcl_Expr‐
       BooleanObj, and Tcl_ExprStringObj.  Those object-based procedures eval‐
       uate an expression held in a Tcl	 object	 instead  of  a	 string.   The
       object  argument	 can  retain  an  internal representation that is more
       efficient to execute.

       The interp argument refers to  an  interpreter  used  to	 evaluate  the
       expression  (e.g.  for variables and nested Tcl commands) and to return
       error information.  interp->result is assumed to be initialized in  the
       standard fashion when they are invoked.

       For  all of these procedures the return value is a standard Tcl result:
       TCL_OK means the expression was successfully evaluated,	and  TCL_ERROR
       means  that  an	error  occurred	 while	evaluating the expression.  If
       TCL_ERROR is returned then interp->result will hold a message  describ‐
       ing the error.  If an error occurs while executing a Tcl command embed‐
       ded in the expression then that error will be returned.

       If the expression is successfully evaluated, then its value is returned
       in  one	of  four  forms,  depending  on	 which	procedure  is invoked.
       Tcl_ExprLong stores an integer value at *longPtr.  If the  expression's
       actual  value  is  a  floating-point number, then it is truncated to an
       integer.	 If the expression's actual value is a non-numeric string then
       an error is returned.

       Tcl_ExprDouble  stores  a  floating-point  value at *doublePtr.	If the
       expression's actual value is an integer, it is converted	 to  floating-
       point.	If  the expression's actual value is a non-numeric string then
       an error is returned.

       Tcl_ExprBoolean stores a 0/1 integer  value  at	*booleanPtr.   If  the
       expression's  actual value is an integer or floating-point number, then
       they store 0 at *booleanPtr if the value was zero and 1 otherwise.   If
       the  expression's  actual value is a non-numeric string then it must be
       one of the values accepted by Tcl_GetBoolean such as ``yes'' or ``no'',
       or else an error occurs.

       Tcl_ExprString  returns	the value of the expression as a string stored
       in interp->result.  If the expression's actual value is an integer then
       Tcl_ExprString converts it to a string using sprintf with a ``%d'' con‐
       verter.	If the expression's actual value is a  floating-point  number,
       then Tcl_ExprString calls Tcl_PrintDouble to convert it to a string.

SEE ALSO
       Tcl_ExprLongObj, Tcl_ExprDoubleObj, Tcl_ExprBooleanObj, Tcl_ExprObj

KEYWORDS
       boolean, double, evaluate, expression, integer, object, string

Tcl				      7.0		       Tcl_ExprLong(3)
[top]
                             _         _         _ 
                            | |       | |       | |     
                            | |       | |       | |     
                         __ | | __ __ | | __ __ | | __  
                         \ \| |/ / \ \| |/ / \ \| |/ /  
                          \ \ / /   \ \ / /   \ \ / /   
                           \   /     \   /     \   /    
                            \_/       \_/       \_/ 
More information is available in HTML format for server UnixWare

List of man pages available for UnixWare

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