source: trunk/minix/commands/awk/l.c@ 15

Last change on this file since 15 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 6.2 KB
RevLine 
[9]1/*
2 * a small awk clone
3 *
4 * (C) 1989 Saeko Hirabauashi & Kouichi Hirabayashi
5 *
6 * Absolutely no warranty. Use this software with your own risk.
7 *
8 * Permission to use, copy, modify and distribute this software for any
9 * purpose and without fee is hereby granted, provided that the above
10 * copyright and disclaimer notice.
11 *
12 * This program was written to fit into 64K+64K memory of the Minix 1.2.
13 */
14
15
16#include <stdio.h>
17#include <ctype.h>
18#include "awk.h"
19
20extern char *srcprg; /* inline program */
21extern FILE *pfp; /* program file */
22
23int sym; /* lexical token */
24int sym1; /* auxiliary lexical token */
25int regexflg; /* set by parser (y.c) to indicate parsing REGEXPR */
26int funflg; /* set by parser (y.c) to indicate parsing FUNCTION */
27int printflg; /* set by parser (y.c) to indicate parsing PRINT */
28int getlineflg; /* set by parser (y.c) to indicate parsing GETLINE */
29char text[BUFSIZ]; /* lexical word */
30char line[BUFSIZ]; /* program line for error message (ring buffer) */
31char *linep = line; /* line pointer */
32char funnam[128]; /* function name for error message */
33int lineno = 1;
34
35lex()
36{
37 int c, d;
38 char *s;
39
40 if (regexflg)
41 return sym = scanreg();
42next:
43 while ((c = Getc()) == ' ' || c == '\t')
44 ;
45 while (c == '#')
46 for (c = Getc(); c != '\n'; c = Getc())
47 ;
48 switch (c) {
49 case '\\':
50 if ((c = Getc()) == '\n') {
51 lineno++;
52 goto next;
53 }
54 break;
55 case '\n':
56 lineno++;
57 break;
58 }
59 switch (c) {
60 case EOF: return sym = 0;
61 case '+': return sym = follow2('=', '+', ADDEQ, INC, ADD);
62 case '-': return sym = follow2('=', '-', SUBEQ, DEC, SUB);
63 case '*': return sym = follow('=', MULTEQ, MULT);
64 case '/': return sym = follow('=', DIVEQ, DIV);
65 case '%': return sym = follow('=', MODEQ, MOD);
66 case '^': return sym = follow('=', POWEQ, POWER);
67 case '=': return sym = follow('=', EQ, ASSIGN);
68 case '!': return sym = follow2('=', '~', NE, NOMATCH, NOT);
69 case '&': return sym = follow('&', AND, BINAND);
70 case '|': sym = follow('|', OR, BINOR);
71 if (printflg && sym == BINOR)
72 sym = R_POUT;
73 return sym;
74 case '<': sym = follow2('=', '<', LE, SHIFTL, LT);
75 if (getlineflg && sym == LT)
76 sym = R_IN;
77 return sym;
78 case '>': sym = follow2('=', '>', GE, SHIFTR, GT);
79 if (printflg) {
80 switch (sym) {
81 case GT: sym = R_OUT; break;
82 case SHIFTR: sym = R_APD; break;
83 }
84 }
85 return sym;
86 case '~': return sym = MATCH; break;
87 case ';': case '\n': return sym = EOL;
88 }
89 if (isalpha(c) || c == '_') {
90 for (s = text; isalnum(c) || c == '_'; ) {
91 *s++ = c; c = Getc();
92 }
93 Ungetc(c);
94 *s = '\0';
95 if ((d = iskeywd(text)) == 0 &&
96 (d = isbuiltin(text, &sym1)) == 0) {
97 if (c == '(')
98 return sym = CALL;
99 else if (funflg) {
100 if ((sym1 = isarg(text)) != -1)
101 return sym = ARG;
102 }
103 }
104 return sym = d ? d : IDENT;
105 }
106 else if (c == '.' || (isdigit(c))) {
107 Ungetc(c);
108 return sym = scannum(text); /* NUMBER */
109 }
110 else if (c == '"')
111 return sym = scanstr(text); /* STRING */
112 return sym = c;
113}
114
115static
116follow(c1, r1, r2)
117{
118 register int c;
119
120 if ((c = Getc()) == c1)
121 return r1;
122 else {
123 Ungetc(c);
124 return r2;
125 }
126}
127
128static
129follow2(c1, c2, r1, r2, r3)
130{
131 register int c;
132
133 if ((c = Getc()) == c1)
134 return r1;
135 else if (c == c2)
136 return r2;
137 else {
138 Ungetc(c);
139 return r3;
140 }
141}
142
143static
144iskeywd(s) char *s;
145{
146 static struct { char *kw; int token; } tab[] = {
147 "BEGIN", BEGIN,
148 "END", END,
149 "break", BREAK,
150 "continue", CONTIN,
151 "delete", DELETE,
152 "do", DO,
153 "else", ELSE,
154 "exit", EXIT,
155 "for", FOR,
156 "func", FUNC,
157 "function", FUNC,
158 "getline", GETLINE,
159 "if", IF,
160 "in", IN,
161 "next", NEXT,
162 "print", PRINT,
163 "printf", PRINTF,
164 "return", RETURN,
165 "sprint", SPRINT,
166 "sprintf", SPRINTF,
167 "while", WHILE,
168 "", 0, 0
169 };
170 register int i;
171
172 for (i = 0; tab[i].token; i++)
173 if (strcmp(tab[i].kw, s) == 0)
174 break;
175 return tab[i].token;
176}
177
178static
179isbuiltin(s, p) char *s; int *p;
180{
181 static struct { char *kw; int type; int token; } tab[] = {
182 "atan2", MATHFUN, ATAN2,
183 "close", STRFUN, CLOSE,
184 "cos", MATHFUN, COS,
185 "exp", MATHFUN, EXP,
186 "gsub", SUBST, RGSUB,
187 "index", STRFUN, INDEX,
188 "int", MATHFUN, INT,
189 "length", STRFUN, LENGTH,
190 "log", MATHFUN, LOG,
191 "match", STRFUN, RMATCH,
192 "sin", MATHFUN, SIN,
193 "sqrt", MATHFUN, SQRT,
194 "rand", MATHFUN, RAND,
195 "srand", MATHFUN, SRAND,
196 "split", STRFUN, SPLIT,
197 "sub", SUBST, RSUB,
198 "substr", STRFUN, SUBSTR,
199 "system", STRFUN, SYSTEM,
200 "", 0, 0
201 };
202 register int i;
203
204 for (i = 0; tab[i].token; i++)
205 if (strcmp(tab[i].kw, s) == 0)
206 break;
207 *p = tab[i].token;
208 return tab[i].type;
209}
210
211static
212scannum(s) char *s;
213{
214 register int c;
215 char *strchr();
216
217 if ((c = Getc()) && strchr("+-", c) != NULL) {
218 *s++ = c; c = Getc();
219 }
220 while (isdigit(c)) {
221 *s++ = c; c = Getc();
222 }
223 if (c == '.') {
224 *s++ = c; c = Getc();
225 while (isdigit(c)) {
226 *s++ = c; c = Getc();
227 }
228 }
229 if (c && strchr("eE", c) != NULL) {
230 *s++ = c; c = Getc();
231 if (c && strchr("+-", c) != NULL) {
232 *s++ = c; c = Getc();
233 }
234 while (isdigit(c)) {
235 *s++ = c; c = Getc();
236 }
237 }
238 *s = '\0';
239 Ungetc(c);
240 return NUMBER;
241}
242
243static
244scanstr(s) char *s;
245{
246 register int c, i, j;
247
248 for (c = Getc(); c != EOF & c != '"'; ) {
249 if (c == '\\') {
250 switch (c = Getc()) {
251 case 'b': c = '\b'; break;
252 case 'f': c = '\f'; break;
253 case 'n': c = '\n'; break;
254 case 'r': c = '\r'; break;
255 case 't': c = '\t'; break;
256 default:
257 if (isdigit(c)) {
258 for (i = j = 0; i < 3 && isdigit(c); c = Getc(), i++)
259 j = j * 8 + c - '0';
260 Ungetc(c);
261 c = j;
262 }
263 break;
264 }
265 }
266 *s++ = c;
267 if (isKanji(c))
268 *s++ = Getc();
269 c = Getc();
270 }
271 *s = '\0';
272 return STRING;
273}
274
275static
276scanreg()
277{
278 register int c;
279 register char *s;
280
281 for (s = text; (c = Getc()) != '/'; )
282 if (c == '\n')
283 error("newline in regular expression");
284 else {
285 if (isKanji(c) || c == '\\') {
286 *s++ = c; c = Getc();
287 }
288 *s++ = c;
289 }
290 *s = '\0';
291 return REGEXP;
292}
293
294static int c0;
295
296Ungetc(c)
297{
298 c0 = c;
299
300 if (linep > line) {
301 if (--linep < line)
302 linep == line + BUFSIZ - 1;
303 }
304}
305
306Getc()
307{
308 register int c;
309 char *s, *t;
310
311 if (c0) {
312 c = c0; c0 = 0;
313 }
314 else if (srcprg)
315 c = *srcprg ? *srcprg++ : EOF;
316 else
317 c = fgetc(pfp);
318
319#if 0
320 if (linep - line == BUFSIZ) {
321printf("!!!\n");
322 for (s = line; *s != '\n' && ((s - line) <BUFSIZ); s++)
323 ;
324printf("***(%d)***\n", *s);
325 for (t = line; s < linep; )
326 *t++ = *++s;
327 }
328#endif
329 *linep++ = c;
330 if ((linep - line) == BUFSIZ)
331 linep = line;
332 return c;
333}
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