source: trunk/minix/commands/m4/eval.c@ 21

Last change on this file since 21 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 5.5 KB
Line 
1/*
2 * eval.c
3 * Facility: m4 macro processor
4 * by: oz
5 */
6
7#include "mdef.h"
8#include "extr.h"
9
10/*
11 * eval - evaluate built-in macros.
12 * argc - number of elements in argv.
13 * argv - element vector :
14 * argv[0] = definition of a user
15 * macro or nil if built-in.
16 * argv[1] = name of the macro or
17 * built-in.
18 * argv[2] = parameters to user-defined
19 * . macro or built-in.
20 * .
21 *
22 * Note that the minimum value for argc is 3. A call in the form
23 * of macro-or-builtin() will result in:
24 * argv[0] = nullstr
25 * argv[1] = macro-or-builtin
26 * argv[2] = nullstr
27 *
28 */
29
30void eval (argv, argc, td)
31register char *argv[];
32register int argc;
33register int td;
34{
35 register int c, n;
36 static int sysval;
37
38#ifdef DEBUG
39 printf("argc = %d\n", argc);
40 for (n = 0; n < argc; n++)
41 printf("argv[%d] = %s\n", n, argv[n]);
42#endif
43 /*
44 * if argc == 3 and argv[2] is null,
45 * then we have macro-or-builtin() type call.
46 * We adjust argc to avoid further checking..
47 *
48 */
49 if (argc == 3 && !*(argv[2]))
50 argc--;
51
52 switch (td & ~STATIC) {
53
54 case DEFITYPE:
55 if (argc > 2)
56 dodefine(argv[2], (argc > 3) ? argv[3] : null);
57 break;
58
59 case PUSDTYPE:
60 if (argc > 2)
61 dopushdef(argv[2], (argc > 3) ? argv[3] : null);
62 break;
63
64 case DUMPTYPE:
65 dodump(argv, argc);
66 break;
67
68 case EXPRTYPE:
69 /*
70 * doexpr - evaluate arithmetic expression
71 *
72 */
73 if (argc > 2)
74 pbnum(expr(argv[2]));
75 break;
76
77 case IFELTYPE:
78 if (argc > 4)
79 doifelse(argv, argc);
80 break;
81
82 case IFDFTYPE:
83 /*
84 * doifdef - select one of two alternatives based
85 * on the existence of another definition
86 */
87 if (argc > 3) {
88 if (lookup(argv[2]) != nil)
89 pbstr(argv[3]);
90 else if (argc > 4)
91 pbstr(argv[4]);
92 }
93 break;
94
95 case LENGTYPE:
96 /*
97 * dolen - find the length of the argument
98 *
99 */
100 if (argc > 2)
101 pbnum((argc > 2) ? strlen(argv[2]) : 0);
102 break;
103
104 case INCRTYPE:
105 /*
106 * doincr - increment the value of the argument
107 *
108 */
109 if (argc > 2)
110 pbnum(atoi(argv[2]) + 1);
111 break;
112
113 case DECRTYPE:
114 /*
115 * dodecr - decrement the value of the argument
116 *
117 */
118 if (argc > 2)
119 pbnum(atoi(argv[2]) - 1);
120 break;
121
122#if unix || vms
123
124 case SYSCTYPE:
125 /*
126 * dosys - execute system command
127 *
128 */
129 if (argc > 2)
130 sysval = system(argv[2]);
131 break;
132
133 case SYSVTYPE:
134 /*
135 * dosysval - return value of the last system call.
136 *
137 */
138 pbnum(sysval);
139 break;
140#endif
141
142 case INCLTYPE:
143 if (argc > 2)
144 if (!doincl(argv[2])) {
145 fprintf(stderr,"m4: %s: ",argv[2]);
146 error("cannot open for read.");
147 }
148 break;
149
150 case SINCTYPE:
151 if (argc > 2)
152 (void) doincl(argv[2]);
153 break;
154#ifdef EXTENDED
155 case PASTTYPE:
156 if (argc > 2)
157 if (!dopaste(argv[2])) {
158 fprintf(stderr,"m4: %s: ",argv[2]);
159 error("cannot open for read.");
160 }
161 break;
162
163 case SPASTYPE:
164 if (argc > 2)
165 (void) dopaste(argv[2]);
166 break;
167#endif
168 case CHNQTYPE:
169 dochq(argv, argc);
170 break;
171
172 case CHNCTYPE:
173 dochc(argv, argc);
174 break;
175
176 case SUBSTYPE:
177 /*
178 * dosub - select substring
179 *
180 */
181 if (argc > 3)
182 dosub(argv,argc);
183 break;
184
185 case SHIFTYPE:
186 /*
187 * doshift - push back all arguments except the
188 * first one (i.e. skip argv[2])
189 */
190 if (argc > 3) {
191 for (n = argc-1; n > 3; n--) {
192 putback(rquote);
193 pbstr(argv[n]);
194 putback(lquote);
195 putback(',');
196 }
197 putback(rquote);
198 pbstr(argv[3]);
199 putback(lquote);
200 }
201 break;
202
203 case DIVRTYPE:
204 if (argc > 2 && (n = atoi(argv[2])) != 0)
205 dodiv(n);
206 else {
207 active = stdout;
208 oindex = 0;
209 }
210 break;
211
212 case UNDVTYPE:
213 doundiv(argv, argc);
214 break;
215
216 case DIVNTYPE:
217 /*
218 * dodivnum - return the number of current
219 * output diversion
220 *
221 */
222 pbnum(oindex);
223 break;
224
225 case UNDFTYPE:
226 /*
227 * doundefine - undefine a previously defined
228 * macro(s) or m4 keyword(s).
229 */
230 if (argc > 2)
231 for (n = 2; n < argc; n++)
232 remhash(argv[n], ALL);
233 break;
234
235 case POPDTYPE:
236 /*
237 * dopopdef - remove the topmost definitions of
238 * macro(s) or m4 keyword(s).
239 */
240 if (argc > 2)
241 for (n = 2; n < argc; n++)
242 remhash(argv[n], TOP);
243 break;
244
245 case MKTMTYPE:
246 /*
247 * dotemp - create a temporary file
248 *
249 */
250 if (argc > 2)
251 pbstr(mktemp(argv[2]));
252 break;
253
254 case TRNLTYPE:
255 /*
256 * dotranslit - replace all characters in the
257 * source string that appears in
258 * the "from" string with the corresponding
259 * characters in the "to" string.
260 *
261 */
262 if (argc > 3) {
263 char temp[MAXTOK];
264 if (argc > 4)
265 map(temp, argv[2], argv[3], argv[4]);
266 else
267 map(temp, argv[2], argv[3], null);
268 pbstr(temp);
269 }
270 else
271 if (argc > 2)
272 pbstr(argv[2]);
273 break;
274
275 case INDXTYPE:
276 /*
277 * doindex - find the index of the second argument
278 * string in the first argument string.
279 * -1 if not present.
280 */
281 pbnum((argc > 3) ? indx(argv[2], argv[3]) : -1);
282 break;
283
284 case ERRPTYPE:
285 /*
286 * doerrp - print the arguments to stderr file
287 *
288 */
289 if (argc > 2) {
290 for (n = 2; n < argc; n++)
291 fprintf(stderr,"%s ", argv[n]);
292 fprintf(stderr, "\n");
293 }
294 break;
295
296 case DNLNTYPE:
297 /*
298 * dodnl - eat-up-to and including newline
299 *
300 */
301 while ((c = gpbc()) != '\n' && c != EOF)
302 ;
303 break;
304
305 case M4WRTYPE:
306 /*
307 * dom4wrap - set up for wrap-up/wind-down activity
308 *
309 */
310 m4wraps = (argc > 2) ? strsave(argv[2]) : null;
311 break;
312
313 case EXITTYPE:
314 /*
315 * doexit - immediate exit from m4.
316 *
317 */
318 exit((argc > 2) ? atoi(argv[2]) : 0);
319 break;
320
321 case DEFNTYPE:
322 if (argc > 2)
323 for (n = 2; n < argc; n++)
324 dodefn(argv[n]);
325 break;
326
327 default:
328 error("m4: major botch in eval.");
329 break;
330 }
331}
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