]>
Commit | Line | Data |
---|---|---|
1eee94d3 GM |
1 | (* StrIO.mod provides simple string input output routines. |
2 | ||
83ffe9cd | 3 | Copyright (C) 2001-2023 Free Software Foundation, Inc. |
1eee94d3 GM |
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 StrIO ; | |
28 | ||
29 | ||
30 | FROM ASCII IMPORT cr, nul, lf, bel, del, bs, nak, etb, ff, eof ; | |
31 | FROM StdIO IMPORT Read, Write ; | |
32 | FROM libc IMPORT isatty ; | |
33 | ||
34 | ||
35 | VAR | |
36 | IsATTY: BOOLEAN ; (* Is default input from the keyboard? *) | |
37 | ||
38 | ||
39 | (* | |
40 | WriteLn - writes a carriage return and a newline | |
41 | character. | |
42 | *) | |
43 | ||
44 | PROCEDURE WriteLn ; | |
45 | BEGIN | |
46 | Echo(cr) ; | |
47 | Write(lf) | |
48 | END WriteLn ; | |
49 | ||
50 | ||
51 | (* | |
52 | ReadString - reads a sequence of characters into a string. | |
53 | Line editing accepts Del, Ctrl H, Ctrl W and | |
54 | Ctrl U. | |
55 | *) | |
56 | ||
57 | PROCEDURE ReadString (VAR a: ARRAY OF CHAR) ; | |
58 | VAR | |
59 | n , | |
60 | high : CARDINAL ; | |
61 | ch : CHAR ; | |
62 | BEGIN | |
63 | high := HIGH(a) ; | |
64 | n := 0 ; | |
65 | REPEAT | |
66 | Read(ch) ; | |
67 | IF (ch=del) OR (ch=bs) | |
68 | THEN | |
69 | IF n=0 | |
70 | THEN | |
71 | Write(bel) | |
72 | ELSE | |
73 | Erase ; | |
74 | DEC(n) | |
75 | END | |
76 | ELSIF ch=nak (* Ctrl U *) | |
77 | THEN | |
78 | WHILE n>0 DO | |
79 | Erase ; | |
80 | DEC(n) | |
81 | END | |
82 | ELSIF ch=etb (* Ctrl W *) | |
83 | THEN | |
84 | IF n=0 | |
85 | THEN | |
86 | Echo(bel) | |
87 | ELSIF AlphaNum(a[n-1]) | |
88 | THEN | |
89 | REPEAT | |
90 | Erase ; | |
91 | DEC(n) | |
92 | UNTIL (n=0) OR (NOT AlphaNum(a[n-1])) | |
93 | ELSE | |
94 | Erase ; | |
95 | DEC(n) | |
96 | END | |
97 | ELSIF n<=high | |
98 | THEN | |
99 | IF (ch=cr) OR (ch=lf) | |
100 | THEN | |
101 | a[n] := nul ; | |
102 | INC(n) | |
103 | ELSIF ch=ff | |
104 | THEN | |
105 | a[0] := ch ; | |
106 | IF high>0 | |
107 | THEN | |
108 | a[1] := nul | |
109 | END ; | |
110 | ch := cr | |
111 | ELSIF ch>=' ' | |
112 | THEN | |
113 | Echo(ch) ; | |
114 | a[n] := ch ; | |
115 | INC(n) | |
116 | ELSIF ch=eof | |
117 | THEN | |
118 | a[n] := ch ; | |
119 | INC(n) ; | |
120 | ch := cr; | |
121 | IF n<=high | |
122 | THEN | |
123 | a[n] := nul | |
124 | END | |
125 | END | |
126 | ELSIF ch#cr | |
127 | THEN | |
128 | Echo(bel) | |
129 | END | |
130 | UNTIL (ch=cr) OR (ch=lf) | |
131 | END ReadString ; | |
132 | ||
133 | ||
134 | (* | |
135 | WriteString - writes a string to the default output. | |
136 | *) | |
137 | ||
138 | PROCEDURE WriteString (a: ARRAY OF CHAR) ; | |
139 | VAR | |
140 | n , | |
141 | high : CARDINAL ; | |
142 | BEGIN | |
143 | high := HIGH(a) ; | |
144 | n := 0 ; | |
145 | WHILE (n <= high) AND (a[n] # nul) DO | |
146 | Write(a[n]) ; | |
147 | INC(n) | |
148 | END | |
149 | END WriteString ; | |
150 | ||
151 | ||
152 | (* | |
153 | Erase - writes a backspace, space and backspace to remove the | |
154 | last character displayed. | |
155 | *) | |
156 | ||
157 | PROCEDURE Erase ; | |
158 | BEGIN | |
159 | Echo(bs) ; | |
160 | Echo(' ') ; | |
161 | Echo(bs) | |
162 | END Erase ; | |
163 | ||
164 | ||
165 | (* | |
166 | Echo - echos the character, ch, onto the output channel if IsATTY | |
167 | is true. | |
168 | *) | |
169 | ||
170 | PROCEDURE Echo (ch: CHAR) ; | |
171 | BEGIN | |
172 | IF IsATTY | |
173 | THEN | |
174 | Write(ch) | |
175 | END | |
176 | END Echo ; | |
177 | ||
178 | ||
179 | (* | |
180 | AlphaNum- returns true if character, ch, is an alphanumeric character. | |
181 | *) | |
182 | ||
183 | PROCEDURE AlphaNum (ch: CHAR) : BOOLEAN ; | |
184 | BEGIN | |
185 | RETURN ((ch>='a') AND (ch<='z')) OR | |
186 | ((ch>='A') AND (ch<='Z')) OR | |
187 | ((ch>='0') AND (ch<='9')) | |
188 | END AlphaNum ; | |
189 | ||
190 | ||
191 | BEGIN | |
192 | (* IsATTY := isatty() *) | |
193 | IsATTY := FALSE | |
194 | END StrIO. |