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