gcc/m2/gm2-libs/SCmdArgs.mod

   1 (* SCmdArgs.mod provides procedures to retrieve arguments from strings.
   2
   3 Copyright (C) 2001-2024 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  *)
  26
  27 IMPLEMENTATION MODULE SCmdArgs ;
  28
  29 FROM ASCII IMPORT cr, nul ;
  30 FROM DynamicStrings IMPORT Length, Slice, char ;
  31
  32 CONST
  33    esc    = '\' ;
  34    space  = ' ' ;
  35    squote = "'" ;
  36    dquote = '"' ;
  37    tab    = ' ' ;
  38
  39
  40 (*
  41    isWhite -
  42 *)
  43
  44 PROCEDURE isWhite (ch: CHAR) : BOOLEAN ;
  45 BEGIN
  46    RETURN (ch=space) OR (ch=tab)
  47 END isWhite ;
  48
  49
  50 (*
  51    skipWhite -
  52 *)
  53
  54 PROCEDURE skipWhite (s: String; i, e: INTEGER) : INTEGER ;
  55 VAR
  56    ch: CHAR ;
  57 BEGIN
  58    WHILE i<e DO
  59       ch := char(s, i) ;
  60       IF isWhite(ch)
  61       THEN
  62          INC(i)
  63       ELSE
  64          RETURN( i )
  65       END
  66    END ;
  67    RETURN( i )
  68 END skipWhite ;
  69
  70
  71 (*
  72    skipOverWhite -
  73 *)
  74
  75 PROCEDURE skipOverWhite (s: String; start, end: INTEGER) : INTEGER ;
  76 BEGIN
  77    INC(start) ;
  78    WHILE (start<end) AND (NOT isWhite(char(s, start))) DO
  79       INC(start)
  80    END ;
  81    RETURN( start )
  82 END skipOverWhite ;
  83
  84
  85 (*
  86    skipOver -
  87 *)
  88
  89 PROCEDURE skipOver (s: String; start, end: INTEGER; ch: CHAR) : INTEGER ;
  90 BEGIN
  91    INC(start) ;
  92    WHILE (start<end) AND (char(s, start)#ch) DO
  93       INC(start)
  94    END ;
  95    RETURN( start )
  96 END skipOver ;
  97
  98
  99 (*
 100    skipNextArg -
 101 *)
 102
 103 PROCEDURE skipNextArg (s: String; start, end: INTEGER) : INTEGER ;
 104 VAR
 105    ch: CHAR ;
 106 BEGIN
 107    IF start<end
 108    THEN
 109       ch := char(s, start) ;
 110       IF ch=dquote
 111       THEN
 112          end := skipOver(s, start, end, dquote)
 113       ELSIF ch=squote
 114       THEN
 115          end := skipOver(s, start, end, squote)
 116       ELSE
 117          end := skipOverWhite(s, start, end)
 118       END
 119    END ;
 120    RETURN( end )
 121 END skipNextArg ;
 122
 123
 124 (*
 125    GetArg - takes a command line and attempts to extract argument, n,
 126             from CmdLine. The resulting argument is placed into, a.
 127             The result of the operation is returned.
 128 *)
 129
 130 PROCEDURE GetArg (CmdLine: String;
 131                   n: CARDINAL; VAR Argi: String) : BOOLEAN ;
 132 VAR
 133    i         : CARDINAL ;
 134    sn,
 135    start, end: INTEGER ;
 136    ch        : CHAR ;
 137 BEGIN
 138    i := 0 ;
 139    start := 0 ;
 140    end := Length(CmdLine) ;
 141    WHILE i<n DO
 142       start := skipWhite(CmdLine, start, end) ;
 143       sn := skipNextArg(CmdLine, start, end) ;
 144       IF sn<end
 145       THEN
 146          start := sn ;
 147          INC(i)
 148       ELSE
 149          RETURN( FALSE )
 150       END
 151    END ;
 152    start := skipWhite(CmdLine, start, end) ;
 153    sn := skipNextArg(CmdLine, start, end) ;
 154    Argi := Slice(CmdLine, start, sn) ;
 155    RETURN( TRUE )
 156 END GetArg ;
 157
 158
 159 (*
 160    Narg - returns the number of arguments available from
 161           command line, CmdLine.
 162 *)
 163
 164 PROCEDURE Narg (CmdLine: String) : CARDINAL ;
 165 VAR
 166    n         : CARDINAL ;
 167    s,
 168    start, end: INTEGER ;
 169 BEGIN
 170    n := 0 ;
 171    start := 0 ;
 172    end := Length(CmdLine) ;
 173    LOOP
 174       start := skipWhite(CmdLine, start, end) ;
 175       s := skipNextArg(CmdLine, start, end) ;
 176       IF s<end
 177       THEN
 178          start := s ;
 179          INC(n)
 180       ELSE
 181          RETURN( n )
 182       END
 183    END
 184 END Narg ;
 185
 186
 187 PROCEDURE Escape (ch: CHAR) : BOOLEAN ;
 188 BEGIN
 189    RETURN( ch=esc )
 190 END Escape ;
 191
 192
 193 PROCEDURE Space (ch: CHAR) : BOOLEAN ;
 194 BEGIN
 195    RETURN( (ch=space) OR (ch=tab) )
 196 END Space ;
 197
 198
 199 PROCEDURE DoubleQuote (ch: CHAR) : BOOLEAN ;
 200 BEGIN
 201    RETURN( ch=dquote )
 202 END DoubleQuote ;
 203
 204
 205 PROCEDURE SingleQuote (ch: CHAR) : BOOLEAN ;
 206 BEGIN
 207    RETURN( ch=squote )
 208 END SingleQuote ;
 209
 210
 211 END SCmdArgs.