tcl7.6 User Commands - subst






NAME

     subst - Perform backslash, command, and  variable  substitu-
     tions


SYNOPSIS

     subst ?-nobackslashes? ?-nocommands? ?-novariables? string





DESCRIPTION

     This command performs variable substitutions,  command  sub-
     stitutions,  and backslash substitutions on its string argu-
     ment and returns the fully-substituted result.  The  substi-
     tutions  are  performed  in  exactly the same way as for Tcl
     commands.  As a result, the string argument is actually sub-
     stituted  twice, once by the Tcl parser in the usual fashion
     for Tcl commands, and again by the subst command.

     If any of the -nobackslashes, -nocommands, or  - novariables
     are  specified, then the corresponding substitutions are not
     performed.  For example, if - nocommands  is  specified,  no
     command  substitution is performed:  open and close brackets
     are treated as ordinary characters with no special interpre-
     tation.

     Note: when it performs its  substitutions,  subst  does  not
     give any special treatment to double quotes or curly braces.
     For example, the script
          set a 44
          subst {xyz {$a}}
     returns ``xyz {44}'', not ``xyz {$a}''.



KEYWORDS

     backslash substitution, command substitution, variable  sub-
     stitution