1 #include "rc.h"
2 #include "exec.h"
3 #include "io.h"
4 #include "getflags.h"
5 #include "fns.h"
6 int getnext(void);
7
8 int
wordchr(int c)9 wordchr(int c)
10 {
11 return !strchr("\n \t#;&|^$=`'{}()<>", c) && c!=EOF;
12 }
13
14 int
idchr(int c)15 idchr(int c)
16 {
17 /*
18 * Formerly:
19 * return 'a'<=c && c<='z' || 'A'<=c && c<='Z' || '0'<=c && c<='9'
20 * || c=='_' || c=='*';
21 */
22 return c>' ' && !strchr("!\"#$%&'()+,-./:;<=>?@[\\]^`{|}~", c);
23 }
24 int future = EOF;
25 int doprompt = 1;
26 int inquote;
27 int incomm;
28 /*
29 * Look ahead in the input stream
30 */
31
32 int
nextc(void)33 nextc(void)
34 {
35 if(future==EOF)
36 future = getnext();
37 return future;
38 }
39 /*
40 * Consume the lookahead character.
41 */
42
43 int
advance(void)44 advance(void)
45 {
46 int c = nextc();
47 lastc = future;
48 future = EOF;
49 return c;
50 }
51 /*
52 * read a character from the input stream
53 */
54
55 int
getnext(void)56 getnext(void)
57 {
58 int c;
59 static int peekc = EOF;
60 if(peekc!=EOF){
61 c = peekc;
62 peekc = EOF;
63 return c;
64 }
65 if(runq->eof)
66 return EOF;
67 if(doprompt)
68 pprompt();
69 c = rchr(runq->cmdfd);
70 if(!inquote && c=='\\'){
71 c = rchr(runq->cmdfd);
72 if(c=='\n' && !incomm){ /* don't continue a comment */
73 doprompt = 1;
74 c=' ';
75 }
76 else{
77 peekc = c;
78 c='\\';
79 }
80 }
81 doprompt = doprompt || c=='\n' || c==EOF;
82 if(c==EOF)
83 runq->eof++;
84 else if(flag['V'] || ndot>=2 && flag['v']) pchr(err, c);
85 return c;
86 }
87
88 void
pprompt(void)89 pprompt(void)
90 {
91 var *prompt;
92 if(runq->iflag){
93 pstr(err, promptstr);
94 flush(err);
95 prompt = vlook("prompt");
96 if(prompt->val && prompt->val->next)
97 promptstr = prompt->val->next->word;
98 else
99 promptstr="\t";
100 }
101 runq->lineno++;
102 doprompt = 0;
103 }
104
105 void
skipwhite(void)106 skipwhite(void)
107 {
108 int c;
109 for(;;){
110 c = nextc();
111 /* Why did this used to be if(!inquote && c=='#') ?? */
112 if(c=='#'){
113 incomm = 1;
114 for(;;){
115 c = nextc();
116 if(c=='\n' || c==EOF) {
117 incomm = 0;
118 break;
119 }
120 advance();
121 }
122 }
123 if(c==' ' || c=='\t')
124 advance();
125 else return;
126 }
127 }
128
129 void
skipnl(void)130 skipnl(void)
131 {
132 int c;
133 for(;;){
134 skipwhite();
135 c = nextc();
136 if(c!='\n')
137 return;
138 advance();
139 }
140 }
141
142 int
nextis(int c)143 nextis(int c)
144 {
145 if(nextc()==c){
146 advance();
147 return 1;
148 }
149 return 0;
150 }
151
152 char*
addtok(char * p,int val)153 addtok(char *p, int val)
154 {
155 if(p==0)
156 return 0;
157 if(p >= &tok[NTOK]){
158 *p = 0;
159 yyerror("token buffer too short");
160 return 0;
161 }
162 *p++=val;
163 return p;
164 }
165
166 char*
addutf(char * p,int c)167 addutf(char *p, int c)
168 {
169 uchar b, m;
170 int i;
171
172 p = addtok(p, c); /* 1-byte UTF runes are special */
173 if(c < Runeself)
174 return p;
175
176 m = 0xc0;
177 b = 0x80;
178 for(i=1; i < UTFmax; i++){
179 if((c&m) == b)
180 break;
181 p = addtok(p, advance());
182 b = m;
183 m = (m >> 1)|0x80;
184 }
185 return p;
186 }
187
188 int lastdol; /* was the last token read '$' or '$#' or '"'? */
189 int lastword; /* was the last token read a word or compound word terminator? */
190
191 int
yylex(void)192 yylex(void)
193 {
194 int c, d = nextc();
195 char *w = tok;
196 struct tree *t;
197 yylval.tree = 0;
198 /*
199 * Embarassing sneakiness: if the last token read was a quoted or unquoted
200 * WORD then we alter the meaning of what follows. If the next character
201 * is `(', we return SUB (a subscript paren) and consume the `('. Otherwise,
202 * if the next character is the first character of a simple or compound word,
203 * we insert a `^' before it.
204 */
205 if(lastword){
206 lastword = 0;
207 if(d=='('){
208 advance();
209 strcpy(tok, "( [SUB]");
210 return SUB;
211 }
212 if(wordchr(d) || d=='\'' || d=='`' || d=='$' || d=='"'){
213 strcpy(tok, "^");
214 return '^';
215 }
216 }
217 inquote = 0;
218 skipwhite();
219 switch(c = advance()){
220 case EOF:
221 lastdol = 0;
222 strcpy(tok, "EOF");
223 return EOF;
224 case '$':
225 lastdol = 1;
226 if(nextis('#')){
227 strcpy(tok, "$#");
228 return COUNT;
229 }
230 if(nextis('"')){
231 strcpy(tok, "$\"");
232 return '"';
233 }
234 strcpy(tok, "$");
235 return '$';
236 case '&':
237 lastdol = 0;
238 if(nextis('&')){
239 skipnl();
240 strcpy(tok, "&&");
241 return ANDAND;
242 }
243 strcpy(tok, "&");
244 return '&';
245 case '|':
246 lastdol = 0;
247 if(nextis(c)){
248 skipnl();
249 strcpy(tok, "||");
250 return OROR;
251 }
252 case '<':
253 case '>':
254 lastdol = 0;
255 /*
256 * funny redirection tokens:
257 * redir: arrow | arrow '[' fd ']'
258 * arrow: '<' | '<<' | '>' | '>>' | '|'
259 * fd: digit | digit '=' | digit '=' digit
260 * digit: '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'
261 * some possibilities are nonsensical and get a message.
262 */
263 *w++=c;
264 t = newtree();
265 switch(c){
266 case '|':
267 t->type = PIPE;
268 t->fd0 = 1;
269 t->fd1 = 0;
270 break;
271 case '>':
272 t->type = REDIR;
273 if(nextis(c)){
274 t->rtype = APPEND;
275 *w++=c;
276 }
277 else t->rtype = WRITE;
278 t->fd0 = 1;
279 break;
280 case '<':
281 t->type = REDIR;
282 if(nextis(c)){
283 t->rtype = HERE;
284 *w++=c;
285 } else if (nextis('>')){
286 t->rtype = RDWR;
287 *w++=c;
288 } else t->rtype = READ;
289 t->fd0 = 0;
290 break;
291 }
292 if(nextis('[')){
293 *w++='[';
294 c = advance();
295 *w++=c;
296 if(c<'0' || '9'<c){
297 RedirErr:
298 *w = 0;
299 yyerror(t->type==PIPE?"pipe syntax"
300 :"redirection syntax");
301 return EOF;
302 }
303 t->fd0 = 0;
304 do{
305 t->fd0 = t->fd0*10+c-'0';
306 *w++=c;
307 c = advance();
308 }while('0'<=c && c<='9');
309 if(c=='='){
310 *w++='=';
311 if(t->type==REDIR)
312 t->type = DUP;
313 c = advance();
314 if('0'<=c && c<='9'){
315 t->rtype = DUPFD;
316 t->fd1 = t->fd0;
317 t->fd0 = 0;
318 do{
319 t->fd0 = t->fd0*10+c-'0';
320 *w++=c;
321 c = advance();
322 }while('0'<=c && c<='9');
323 }
324 else{
325 if(t->type==PIPE)
326 goto RedirErr;
327 t->rtype = CLOSE;
328 }
329 }
330 if(c!=']'
331 || t->type==DUP && (t->rtype==HERE || t->rtype==APPEND))
332 goto RedirErr;
333 *w++=']';
334 }
335 *w='\0';
336 yylval.tree = t;
337 if(t->type==PIPE)
338 skipnl();
339 return t->type;
340 case '\'':
341 lastdol = 0;
342 lastword = 1;
343 inquote = 1;
344 for(;;){
345 c = advance();
346 if(c==EOF)
347 break;
348 if(c=='\''){
349 if(nextc()!='\'')
350 break;
351 advance();
352 }
353 w = addutf(w, c);
354 }
355 if(w!=0)
356 *w='\0';
357 t = token(tok, WORD);
358 t->quoted = 1;
359 yylval.tree = t;
360 return t->type;
361 }
362 if(!wordchr(c)){
363 lastdol = 0;
364 tok[0] = c;
365 tok[1]='\0';
366 return c;
367 }
368 for(;;){
369 if(c=='*' || c=='[' || c=='?' || c==GLOB)
370 w = addtok(w, GLOB);
371 w = addutf(w, c);
372 c = nextc();
373 if(lastdol?!idchr(c):!wordchr(c)) break;
374 advance();
375 }
376
377 lastword = 1;
378 lastdol = 0;
379 if(w!=0)
380 *w='\0';
381 t = klook(tok);
382 if(t->type!=WORD)
383 lastword = 0;
384 t->quoted = 0;
385 yylval.tree = t;
386 return t->type;
387 }
388