| 1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software contributed to Berkeley by |
| 6 | * Kenneth Almquist. |
| 7 | * |
| 8 | * %sccs.include.redist.c% |
| 9 | */ |
| 10 | |
| 11 | #ifndef lint |
| 12 | static char sccsid[] = "@(#)input.c 5.7 (Berkeley) %G%"; |
| 13 | #endif /* not lint */ |
| 14 | |
| 15 | /* |
| 16 | * This file implements the input routines used by the parser. |
| 17 | */ |
| 18 | |
| 19 | #include <stdio.h> /* defines BUFSIZ */ |
| 20 | #include "shell.h" |
| 21 | #include <fcntl.h> |
| 22 | #include <errno.h> |
| 23 | #include "syntax.h" |
| 24 | #include "input.h" |
| 25 | #include "output.h" |
| 26 | #include "options.h" |
| 27 | #include "memalloc.h" |
| 28 | #include "error.h" |
| 29 | #include "alias.h" |
| 30 | #include "parser.h" |
| 31 | #include "myhistedit.h" |
| 32 | |
| 33 | #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ |
| 34 | |
| 35 | MKINIT |
| 36 | struct strpush { |
| 37 | struct strpush *prev; /* preceding string on stack */ |
| 38 | char *prevstring; |
| 39 | int prevnleft; |
| 40 | struct alias *ap; /* if push was associated with an alias */ |
| 41 | }; |
| 42 | |
| 43 | /* |
| 44 | * The parsefile structure pointed to by the global variable parsefile |
| 45 | * contains information about the current file being read. |
| 46 | */ |
| 47 | |
| 48 | MKINIT |
| 49 | struct parsefile { |
| 50 | struct parsefile *prev; /* preceding file on stack */ |
| 51 | int linno; /* current line */ |
| 52 | int fd; /* file descriptor (or -1 if string) */ |
| 53 | int nleft; /* number of chars left in buffer */ |
| 54 | char *nextc; /* next char in buffer */ |
| 55 | char *buf; /* input buffer */ |
| 56 | struct strpush *strpush; /* for pushing strings at this level */ |
| 57 | struct strpush basestrpush; /* so pushing one is fast */ |
| 58 | }; |
| 59 | |
| 60 | |
| 61 | int plinno = 1; /* input line number */ |
| 62 | MKINIT int parsenleft; /* copy of parsefile->nleft */ |
| 63 | char *parsenextc; /* copy of parsefile->nextc */ |
| 64 | MKINIT struct parsefile basepf; /* top level input file */ |
| 65 | char basebuf[BUFSIZ]; /* buffer for top level input file */ |
| 66 | struct parsefile *parsefile = &basepf; /* current input file */ |
| 67 | char *pushedstring; /* copy of parsenextc when text pushed back */ |
| 68 | int pushednleft; /* copy of parsenleft when text pushed back */ |
| 69 | int init_editline = 0; /* editline library initialized? */ |
| 70 | int whichprompt; /* 1 == PS1, 2 == PS2 */ |
| 71 | |
| 72 | EditLine *el; /* cookie for editline package */ |
| 73 | |
| 74 | #ifdef __STDC__ |
| 75 | STATIC void pushfile(void); |
| 76 | #else |
| 77 | STATIC void pushfile(); |
| 78 | #endif |
| 79 | |
| 80 | |
| 81 | |
| 82 | #ifdef mkinit |
| 83 | INCLUDE "input.h" |
| 84 | INCLUDE "error.h" |
| 85 | |
| 86 | INIT { |
| 87 | extern char basebuf[]; |
| 88 | |
| 89 | basepf.nextc = basepf.buf = basebuf; |
| 90 | } |
| 91 | |
| 92 | RESET { |
| 93 | if (exception != EXSHELLPROC) |
| 94 | parsenleft = 0; /* clear input buffer */ |
| 95 | popallfiles(); |
| 96 | } |
| 97 | |
| 98 | SHELLPROC { |
| 99 | popallfiles(); |
| 100 | } |
| 101 | #endif |
| 102 | |
| 103 | |
| 104 | /* |
| 105 | * Read a line from the script. |
| 106 | */ |
| 107 | |
| 108 | char * |
| 109 | pfgets(line, len) |
| 110 | char *line; |
| 111 | { |
| 112 | register char *p = line; |
| 113 | int nleft = len; |
| 114 | int c; |
| 115 | |
| 116 | while (--nleft > 0) { |
| 117 | c = pgetc_macro(); |
| 118 | if (c == PEOF) { |
| 119 | if (p == line) |
| 120 | return NULL; |
| 121 | break; |
| 122 | } |
| 123 | *p++ = c; |
| 124 | if (c == '\n') |
| 125 | break; |
| 126 | } |
| 127 | *p = '\0'; |
| 128 | return line; |
| 129 | } |
| 130 | |
| 131 | |
| 132 | |
| 133 | /* |
| 134 | * Read a character from the script, returning PEOF on end of file. |
| 135 | * Nul characters in the input are silently discarded. |
| 136 | */ |
| 137 | |
| 138 | int |
| 139 | pgetc() { |
| 140 | return pgetc_macro(); |
| 141 | } |
| 142 | |
| 143 | |
| 144 | /* |
| 145 | * Refill the input buffer and return the next input character: |
| 146 | * |
| 147 | * 1) If a string was pushed back on the input, pop it; |
| 148 | * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading |
| 149 | * from a string so we can't refill the buffer, return EOF. |
| 150 | * 3) Call read to read in the characters. |
| 151 | * 4) Delete all nul characters from the buffer. |
| 152 | */ |
| 153 | |
| 154 | int |
| 155 | preadbuffer() { |
| 156 | register char *p, *q; |
| 157 | register int i; |
| 158 | register int something; |
| 159 | extern EditLine *el; |
| 160 | |
| 161 | if (parsefile->strpush) { |
| 162 | popstring(); |
| 163 | if (--parsenleft >= 0) |
| 164 | return (*parsenextc++); |
| 165 | } |
| 166 | if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) |
| 167 | return PEOF; |
| 168 | flushout(&output); |
| 169 | flushout(&errout); |
| 170 | retry: |
| 171 | p = parsenextc = parsefile->buf; |
| 172 | if (parsefile->fd == 0 && el) { |
| 173 | char *rl_cp; |
| 174 | int len; |
| 175 | |
| 176 | rl_cp = el_gets(el, &len); |
| 177 | if (rl_cp == NULL) { |
| 178 | i = 0; |
| 179 | goto eof; |
| 180 | } |
| 181 | strcpy(p, rl_cp); /* XXX - BUFSIZE should redesign so not necessary */ |
| 182 | i = len; |
| 183 | |
| 184 | } else { |
| 185 | regular_read: |
| 186 | i = read(parsefile->fd, p, BUFSIZ - 1); |
| 187 | } |
| 188 | eof: |
| 189 | if (i <= 0) { |
| 190 | if (i < 0) { |
| 191 | if (errno == EINTR) |
| 192 | goto retry; |
| 193 | if (parsefile->fd == 0 && errno == EWOULDBLOCK) { |
| 194 | int flags = fcntl(0, F_GETFL, 0); |
| 195 | if (flags >= 0 && flags & O_NONBLOCK) { |
| 196 | flags &=~ O_NONBLOCK; |
| 197 | if (fcntl(0, F_SETFL, flags) >= 0) { |
| 198 | out2str("sh: turning off NDELAY mode\n"); |
| 199 | goto retry; |
| 200 | } |
| 201 | } |
| 202 | } |
| 203 | } |
| 204 | parsenleft = EOF_NLEFT; |
| 205 | return PEOF; |
| 206 | } |
| 207 | parsenleft = i - 1; /* we're returning one char in this call */ |
| 208 | |
| 209 | /* delete nul characters */ |
| 210 | something = 0; |
| 211 | for (;;) { |
| 212 | if (*p == '\0') |
| 213 | break; |
| 214 | if (*p != ' ' && *p != '\t' && *p != '\n') |
| 215 | something = 1; |
| 216 | p++; |
| 217 | if (--i <= 0) { |
| 218 | *p = '\0'; |
| 219 | goto done; /* no nul characters */ |
| 220 | } |
| 221 | } |
| 222 | /* |
| 223 | * remove nuls |
| 224 | */ |
| 225 | q = p++; |
| 226 | while (--i > 0) { |
| 227 | if (*p != '\0') |
| 228 | *q++ = *p; |
| 229 | p++; |
| 230 | } |
| 231 | *q = '\0'; |
| 232 | if (q == parsefile->buf) |
| 233 | goto retry; /* buffer contained nothing but nuls */ |
| 234 | parsenleft = q - parsefile->buf - 1; |
| 235 | |
| 236 | done: |
| 237 | if (parsefile->fd == 0 && hist && something) { |
| 238 | INTOFF; |
| 239 | history(hist, whichprompt == 1 ? H_ENTER : H_ADD, |
| 240 | parsefile->buf); |
| 241 | INTON; |
| 242 | } |
| 243 | if (vflag) { |
| 244 | /* |
| 245 | * This isn't right. Most shells coordinate it with |
| 246 | * reading a line at a time. I honestly don't know if its |
| 247 | * worth it. |
| 248 | */ |
| 249 | i = parsenleft + 1; |
| 250 | p = parsefile->buf; |
| 251 | for (; i--; p++) |
| 252 | out2c(*p) |
| 253 | flushout(out2); |
| 254 | } |
| 255 | return *parsenextc++; |
| 256 | } |
| 257 | |
| 258 | /* |
| 259 | * Undo the last call to pgetc. Only one character may be pushed back. |
| 260 | * PEOF may be pushed back. |
| 261 | */ |
| 262 | |
| 263 | void |
| 264 | pungetc() { |
| 265 | parsenleft++; |
| 266 | parsenextc--; |
| 267 | } |
| 268 | |
| 269 | /* |
| 270 | * Push a string back onto the input at this current parsefile level. |
| 271 | * We handle aliases this way. |
| 272 | */ |
| 273 | void |
| 274 | pushstring(s, len, ap) |
| 275 | char *s; |
| 276 | int len; |
| 277 | void *ap; |
| 278 | { |
| 279 | struct strpush *sp; |
| 280 | |
| 281 | INTOFF; |
| 282 | /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/ |
| 283 | if (parsefile->strpush) { |
| 284 | sp = ckmalloc(sizeof (struct strpush)); |
| 285 | sp->prev = parsefile->strpush; |
| 286 | parsefile->strpush = sp; |
| 287 | } else |
| 288 | sp = parsefile->strpush = &(parsefile->basestrpush); |
| 289 | sp->prevstring = parsenextc; |
| 290 | sp->prevnleft = parsenleft; |
| 291 | sp->ap = (struct alias *)ap; |
| 292 | if (ap) |
| 293 | ((struct alias *)ap)->flag |= ALIASINUSE; |
| 294 | parsenextc = s; |
| 295 | parsenleft = len; |
| 296 | INTON; |
| 297 | } |
| 298 | |
| 299 | popstring() |
| 300 | { |
| 301 | struct strpush *sp = parsefile->strpush; |
| 302 | |
| 303 | INTOFF; |
| 304 | parsenextc = sp->prevstring; |
| 305 | parsenleft = sp->prevnleft; |
| 306 | /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ |
| 307 | if (sp->ap) |
| 308 | sp->ap->flag &= ~ALIASINUSE; |
| 309 | parsefile->strpush = sp->prev; |
| 310 | if (sp != &(parsefile->basestrpush)) |
| 311 | ckfree(sp); |
| 312 | INTON; |
| 313 | } |
| 314 | |
| 315 | /* |
| 316 | * Set the input to take input from a file. If push is set, push the |
| 317 | * old input onto the stack first. |
| 318 | */ |
| 319 | |
| 320 | void |
| 321 | setinputfile(fname, push) |
| 322 | char *fname; |
| 323 | { |
| 324 | int fd; |
| 325 | int fd2; |
| 326 | |
| 327 | INTOFF; |
| 328 | if ((fd = open(fname, O_RDONLY)) < 0) |
| 329 | error("Can't open %s", fname); |
| 330 | if (fd < 10) { |
| 331 | fd2 = copyfd(fd, 10); |
| 332 | close(fd); |
| 333 | if (fd2 < 0) |
| 334 | error("Out of file descriptors"); |
| 335 | fd = fd2; |
| 336 | } |
| 337 | setinputfd(fd, push); |
| 338 | INTON; |
| 339 | } |
| 340 | |
| 341 | |
| 342 | /* |
| 343 | * Like setinputfile, but takes an open file descriptor. Call this with |
| 344 | * interrupts off. |
| 345 | */ |
| 346 | |
| 347 | void |
| 348 | setinputfd(fd, push) { |
| 349 | if (push) { |
| 350 | pushfile(); |
| 351 | parsefile->buf = ckmalloc(BUFSIZ); |
| 352 | } |
| 353 | if (parsefile->fd > 0) |
| 354 | close(parsefile->fd); |
| 355 | parsefile->fd = fd; |
| 356 | if (parsefile->buf == NULL) |
| 357 | parsefile->buf = ckmalloc(BUFSIZ); |
| 358 | parsenleft = 0; |
| 359 | plinno = 1; |
| 360 | } |
| 361 | |
| 362 | |
| 363 | /* |
| 364 | * Like setinputfile, but takes input from a string. |
| 365 | */ |
| 366 | |
| 367 | void |
| 368 | setinputstring(string, push) |
| 369 | char *string; |
| 370 | { |
| 371 | INTOFF; |
| 372 | if (push) |
| 373 | pushfile(); |
| 374 | parsenextc = string; |
| 375 | parsenleft = strlen(string); |
| 376 | parsefile->buf = NULL; |
| 377 | plinno = 1; |
| 378 | INTON; |
| 379 | } |
| 380 | |
| 381 | |
| 382 | |
| 383 | /* |
| 384 | * To handle the "." command, a stack of input files is used. Pushfile |
| 385 | * adds a new entry to the stack and popfile restores the previous level. |
| 386 | */ |
| 387 | |
| 388 | STATIC void |
| 389 | pushfile() { |
| 390 | struct parsefile *pf; |
| 391 | |
| 392 | parsefile->nleft = parsenleft; |
| 393 | parsefile->nextc = parsenextc; |
| 394 | parsefile->linno = plinno; |
| 395 | pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); |
| 396 | pf->prev = parsefile; |
| 397 | pf->fd = -1; |
| 398 | pf->strpush = NULL; |
| 399 | pf->basestrpush.prev = NULL; |
| 400 | parsefile = pf; |
| 401 | } |
| 402 | |
| 403 | |
| 404 | void |
| 405 | popfile() { |
| 406 | struct parsefile *pf = parsefile; |
| 407 | |
| 408 | INTOFF; |
| 409 | if (pf->fd >= 0) |
| 410 | close(pf->fd); |
| 411 | if (pf->buf) |
| 412 | ckfree(pf->buf); |
| 413 | while (pf->strpush) |
| 414 | popstring(); |
| 415 | parsefile = pf->prev; |
| 416 | ckfree(pf); |
| 417 | parsenleft = parsefile->nleft; |
| 418 | parsenextc = parsefile->nextc; |
| 419 | plinno = parsefile->linno; |
| 420 | INTON; |
| 421 | } |
| 422 | |
| 423 | |
| 424 | /* |
| 425 | * Return to top level. |
| 426 | */ |
| 427 | |
| 428 | void |
| 429 | popallfiles() { |
| 430 | while (parsefile != &basepf) |
| 431 | popfile(); |
| 432 | } |
| 433 | |
| 434 | |
| 435 | |
| 436 | /* |
| 437 | * Close the file(s) that the shell is reading commands from. Called |
| 438 | * after a fork is done. |
| 439 | */ |
| 440 | |
| 441 | void |
| 442 | closescript() { |
| 443 | popallfiles(); |
| 444 | if (parsefile->fd > 0) { |
| 445 | close(parsefile->fd); |
| 446 | parsefile->fd = 0; |
| 447 | } |
| 448 | } |