gcc/m2/gm2-libs/SFIO.mod

   1 (* SFIO.mod provides a String interface to the opening routines of FIO.
   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 SFIO ;
  28
  29 FROM ASCII IMPORT nul ;
  30
  31 FROM DynamicStrings IMPORT string, Length, InitString, ConCatChar,
  32                            InitStringDB, InitStringCharStarDB,
  33                            InitStringCharDB, MultDB, DupDB, SliceDB ;
  34
  35 FROM FIO IMPORT exists, openToRead, openToWrite, openForRandom, WriteNBytes, ReadChar,
  36                 EOLN, EOF, IsNoError ;
  37
  38 (*
  39 #undef GM2_DEBUG_SFIO
  40 #if defined(GM2_DEBUG_SFIO)
  41 #  define InitString(X) InitStringDB(X, __FILE__, __LINE__)
  42 #  define InitStringCharStar(X) InitStringCharStarDB(X, __FILE__, __LINE__)
  43 #  define InitStringChar(X) InitStringCharDB(X, __FILE__, __LINE__)
  44 #  define Mult(X,Y) MultDB(X, Y, __FILE__, __LINE__)
  45 #  define Dup(X) DupDB(X, __FILE__, __LINE__)
  46 #  define Slice(X,Y,Z) SliceDB(X, Y, Z, __FILE__, __LINE__)
  47 #endif
  48 *)
  49
  50
  51 (*
  52    Exists - returns TRUE if a file named, fname exists for reading.
  53 *)
  54
  55 PROCEDURE Exists (fname: String) : BOOLEAN ;
  56 BEGIN
  57    RETURN exists (string (fname), Length (fname))
  58 END Exists ;
  59
  60
  61 (*
  62    OpenToRead - attempts to open a file, fname, for reading and
  63                 it returns this file.
  64                 The success of this operation can be checked by
  65                 calling IsNoError.
  66 *)
  67
  68 PROCEDURE OpenToRead (fname: String) : File ;
  69 BEGIN
  70    RETURN openToRead (string (fname), Length (fname))
  71 END OpenToRead ;
  72
  73
  74 (*
  75    OpenToWrite - attempts to open a file, fname, for write and
  76                  it returns this file.
  77                  The success of this operation can be checked by
  78                  calling IsNoError.
  79 *)
  80
  81 PROCEDURE OpenToWrite (fname: String) : File ;
  82 BEGIN
  83    RETURN openToWrite (string (fname), Length (fname))
  84 END OpenToWrite ;
  85
  86
  87 (*
  88    OpenForRandom - attempts to open a file, fname, for random access
  89                    read or write and it returns this file.
  90                    The success of this operation can be checked by
  91                    calling IsNoError.
  92                    towrite, determines whether the file should be
  93                    opened for writing or reading.
  94                    if towrite is TRUE or whether the previous file should
  95                    be left alone, allowing this descriptor to seek
  96                    and modify an existing file.
  97 *)
  98
  99 PROCEDURE OpenForRandom (fname: String; towrite, newfile: BOOLEAN) : File ;
 100 BEGIN
 101    RETURN openForRandom (string (fname), Length (fname), towrite, newfile)
 102 END OpenForRandom ;
 103
 104
 105 (*
 106    WriteS - writes a string, s, to, file. It returns the String, s.
 107 *)
 108
 109 PROCEDURE WriteS (file: File; s: String) : String ;
 110 VAR
 111    nBytes: CARDINAL ;
 112 BEGIN
 113    IF s#NIL
 114    THEN
 115       nBytes := WriteNBytes(file, Length(s), string(s))
 116    END ;
 117    RETURN( s )
 118 END WriteS ;
 119
 120
 121 (*
 122    ReadS - reads and returns a string from, file.
 123            It stops reading the string at the end of line or end of file.
 124            It consumes the newline at the end of line but does not place
 125            this into the returned string.
 126 *)
 127
 128 PROCEDURE ReadS (file: File) : String ;
 129 VAR
 130    s: String ;
 131 BEGIN
 132    s := InitString ('') ;
 133    WHILE (NOT EOLN (file)) AND (NOT EOF (file)) AND IsNoError (file) DO
 134       s := ConCatChar (s, ReadChar (file))
 135    END ;
 136    IF EOLN (file)
 137    THEN
 138       (* consume nl *)
 139       IF ReadChar (file) = nul
 140       THEN
 141       END
 142    END ;
 143    RETURN s
 144 END ReadS ;
 145
 146
 147 END SFIO.