Страницы справочника OS X

Эта страница руководства является частью версии 5.0 Инструментов XCode

Читать страницы руководства

Tcl_SubstObj(3)                            Tcl Library Procedures                            Tcl_SubstObj(3)



____________________________________________________________________________________________________________

NAME
       Tcl_SubstObj - perform substitutions on Tcl objects

SYNOPSIS
       #include <tcl.h>

       Tcl_Obj *
       Tcl_SubstObj(interp, objPtr, flags)

ARGUMENTS
       Tcl_Interp *interp (in)            Interpreter  in which to execute Tcl scripts and lookup variables.
                                          If an error occurs, the interpreter's result is modified  to  hold
                                          an error message.

       Tcl_Obj *objPtr (in)               A Tcl object containing the string to perform substitutions on.

       int flags (in)                     ORed  combination of flag bits that specify which substitutions to
                                          perform.  The flags  TCL_SUBST_COMMANDS,  TCL_SUBST_VARIABLES  and
                                          TCL_SUBST_BACKSLASHES  are  currently supported, and TCL_SUBST_ALL
                                          is provided as a convenience for the common case where all substi-tutions substitutions
                                          tutions are desired.
____________________________________________________________________________________________________________

DESCRIPTION
       The  Tcl_SubstObj  function  is  used to perform substitutions on strings in the fashion of the subst
       command.  It gets the value of the string contained in objPtr and scans it,  copying  characters  and
       performing the chosen substitutions as it goes to an output object which is returned as the result of
       the function.  In the event of an error occurring during the execution of a command or variable  sub-stitution, substitution,
       stitution, the function returns NULL and an error message is left in interp's result.

       Three  kinds  of  substitutions  are  supported.  When the TCL_SUBST_BACKSLASHES bit is set in flags,
       sequences that look like backslash substitutions for Tcl commands are replaced by their corresponding
       character.

       When the TCL_SUBST_VARIABLES bit is set in flags, sequences that look like variable substitutions for
       Tcl commands are replaced by the contents of the named variable.

       When the TCL_SUBST_COMMANDS bit is set in flags, sequences that look like command  substitutions  for
       Tcl  commands  are  replaced  by  the  result of evaluating that script.  Where an uncaught "continue
       exception" occurs during the evaluation of a command substitution, an empty string is substituted for
       the command.  Where an uncaught "break exception" occurs during the evaluation of a command substitu-tion, substitution,
       tion, the result of the whole substitution on objPtr will  be  truncated  at  the  point  immediately
       before  the  start of the command substitution, and no characters will be added to the result or sub-stitutions substitutions
       stitutions performed after that point.

SEE ALSO
       subst(n)

KEYWORDS
       backslash substitution, command substitution, variable substitution



Tcl                                                  8.4                                     Tcl_SubstObj(3)