xref: /netbsd/bin/ksh/shf.c (revision af3bac7d)
1 /*	$NetBSD: shf.c,v 1.15 2021/11/06 06:40:33 msaitoh Exp $	*/
2 
3 /*
4  *  Shell file I/O routines
5  */
6 #include <sys/cdefs.h>
7 
8 #ifndef lint
9 __RCSID("$NetBSD: shf.c,v 1.15 2021/11/06 06:40:33 msaitoh Exp $");
10 #endif
11 
12 #include <sys/stat.h>
13 
14 #include "sh.h"
15 #include "ksh_limval.h"
16 
17 
18 /* flags to shf_emptybuf() */
19 #define EB_READSW	0x01	/* about to switch to reading */
20 #define EB_GROW		0x02	/* grow buffer if necessary (STRING+DYNAMIC) */
21 
22 /*
23  * Replacement stdio routines.  Stdio is too flakey on too many machines
24  * to be useful when you have multiple processes using the same underlying
25  * file descriptors.
26  */
27 
28 static int	shf_fillbuf	ARGS((struct shf *shf));
29 static int	shf_emptybuf	ARGS((struct shf *shf, int flags));
30 
31 /* Open a file.  First three args are for open(), last arg is flags for
32  * this package.  Returns NULL if file could not be opened, or if a dup
33  * fails.
34  */
35 struct shf *
shf_open(name,oflags,mode,sflags)36 shf_open(name, oflags, mode, sflags)
37 	const char *name;
38 	int oflags;
39 	int mode;
40 	int sflags;
41 {
42 	struct shf *shf;
43 	int bsize = sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
44 	int fd;
45 
46 	/* Done before open so if alloca fails, fd won't be lost. */
47 	shf = (struct shf *) alloc(sizeof(struct shf) + bsize, ATEMP);
48 	shf->areap = ATEMP;
49 	shf->buf = (unsigned char *) &shf[1];
50 	shf->bsize = bsize;
51 	shf->flags = SHF_ALLOCS;
52 	/* Rest filled in by reopen. */
53 
54 	fd = open(name, oflags, mode);
55 	if (fd < 0) {
56 		afree(shf, shf->areap);
57 		return NULL;
58 	}
59 	if ((sflags & SHF_MAPHI) && fd < FDBASE) {
60 		int nfd;
61 
62 		nfd = ksh_dupbase(fd, FDBASE);
63 		close(fd);
64 		if (nfd < 0) {
65 			afree(shf, shf->areap);
66 			return NULL;
67 		}
68 		fd = nfd;
69 	}
70 	sflags &= ~SHF_ACCMODE;
71 	sflags |= (oflags & O_ACCMODE) == O_RDONLY ? SHF_RD
72 		  : ((oflags & O_ACCMODE) == O_WRONLY ? SHF_WR
73 		     : SHF_RDWR);
74 
75 	return shf_reopen(fd, sflags, shf);
76 }
77 
78 /* Set up the shf structure for a file descriptor.  Doesn't fail. */
79 struct shf *
shf_fdopen(fd,sflags,shf)80 shf_fdopen(fd, sflags, shf)
81 	int fd;
82 	int sflags;
83 	struct shf *shf;
84 {
85 	int bsize = sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
86 
87 	/* use fcntl() to figure out correct read/write flags */
88 	if (sflags & SHF_GETFL) {
89 		int flags = fcntl(fd, F_GETFL, 0);
90 
91 		if (flags < 0)
92 			/* will get an error on first read/write */
93 			sflags |= SHF_RDWR;
94 		else
95 			switch (flags & O_ACCMODE) {
96 			case O_RDONLY: sflags |= SHF_RD; break;
97 			case O_WRONLY: sflags |= SHF_WR; break;
98 			case O_RDWR: sflags |= SHF_RDWR; break;
99 			}
100 	}
101 
102 	if (!(sflags & (SHF_RD | SHF_WR)))
103 		internal_errorf(1, "shf_fdopen: missing read/write");
104 
105 	if (shf) {
106 		if (bsize) {
107 			shf->buf = (unsigned char *) alloc(bsize, ATEMP);
108 			sflags |= SHF_ALLOCB;
109 		} else
110 			shf->buf = (unsigned char *) 0;
111 	} else {
112 		shf = (struct shf *) alloc(sizeof(struct shf) + bsize, ATEMP);
113 		shf->buf = (unsigned char *) &shf[1];
114 		sflags |= SHF_ALLOCS;
115 	}
116 	shf->areap = ATEMP;
117 	shf->fd = fd;
118 	shf->rp = shf->wp = shf->buf;
119 	shf->rnleft = 0;
120 	shf->rbsize = bsize;
121 	shf->wnleft = 0; /* force call to shf_emptybuf() */
122 	shf->wbsize = sflags & SHF_UNBUF ? 0 : bsize;
123 	shf->flags = sflags;
124 	shf->errno_ = 0;
125 	shf->bsize = bsize;
126 	if (sflags & SHF_CLEXEC)
127 		fd_clexec(fd);
128 	return shf;
129 }
130 
131 /* Set up an existing shf (and buffer) to use the given fd */
132 struct shf *
shf_reopen(fd,sflags,shf)133 shf_reopen(fd, sflags, shf)
134 	int fd;
135 	int sflags;
136 	struct shf *shf;
137 {
138 	int bsize = sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
139 
140 	/* use fcntl() to figure out correct read/write flags */
141 	if (sflags & SHF_GETFL) {
142 		int flags = fcntl(fd, F_GETFL, 0);
143 
144 		if (flags < 0)
145 			/* will get an error on first read/write */
146 			sflags |= SHF_RDWR;
147 		else
148 			switch (flags & O_ACCMODE) {
149 			case O_RDONLY: sflags |= SHF_RD; break;
150 			case O_WRONLY: sflags |= SHF_WR; break;
151 			case O_RDWR: sflags |= SHF_RDWR; break;
152 			}
153 	}
154 
155 	if (!(sflags & (SHF_RD | SHF_WR)))
156 		internal_errorf(1, "shf_reopen: missing read/write");
157 	if (!shf || !shf->buf || shf->bsize < bsize)
158 		internal_errorf(1, "shf_reopen: bad shf/buf/bsize");
159 
160 	/* assumes shf->buf and shf->bsize already set up */
161 	shf->fd = fd;
162 	shf->rp = shf->wp = shf->buf;
163 	shf->rnleft = 0;
164 	shf->rbsize = bsize;
165 	shf->wnleft = 0; /* force call to shf_emptybuf() */
166 	shf->wbsize = sflags & SHF_UNBUF ? 0 : bsize;
167 	shf->flags = (shf->flags & (SHF_ALLOCS | SHF_ALLOCB)) | sflags;
168 	shf->errno_ = 0;
169 	if (sflags & SHF_CLEXEC)
170 		fd_clexec(fd);
171 	return shf;
172 }
173 
174 /* Open a string for reading or writing.  If reading, bsize is the number
175  * of bytes that can be read.  If writing, bsize is the maximum number of
176  * bytes that can be written.  If shf is not null, it is filled in and
177  * returned, if it is null, shf is allocated.  If writing and buf is null
178  * and SHF_DYNAMIC is set, the buffer is allocated (if bsize > 0, it is
179  * used for the initial size).  Doesn't fail.
180  * When writing, a byte is reserved for a trailing null - see shf_sclose().
181  */
182 struct shf *
shf_sopen(buf,bsize,sflags,shf)183 shf_sopen(buf, bsize, sflags, shf)
184 	char *buf;
185 	int bsize;
186 	int sflags;
187 	struct shf *shf;
188 {
189 	/* can't have a read+write string */
190 	if (!(sflags & (SHF_RD | SHF_WR))
191 	    || (sflags & (SHF_RD | SHF_WR)) == (SHF_RD | SHF_WR))
192 		internal_errorf(1, "shf_sopen: flags 0x%x", sflags);
193 
194 	if (!shf) {
195 		shf = (struct shf *) alloc(sizeof(struct shf), ATEMP);
196 		sflags |= SHF_ALLOCS;
197 	}
198 	shf->areap = ATEMP;
199 	if (!buf && (sflags & SHF_WR) && (sflags & SHF_DYNAMIC)) {
200 		if (bsize <= 0)
201 			bsize = 64;
202 		sflags |= SHF_ALLOCB;
203 		buf = alloc(bsize, shf->areap);
204 	}
205 	shf->fd = -1;
206 	shf->buf = shf->rp = shf->wp = (unsigned char *) buf;
207 	shf->rnleft = bsize;
208 	shf->rbsize = bsize;
209 	shf->wnleft = bsize - 1;	/* space for a '\0' */
210 	shf->wbsize = bsize;
211 	shf->flags = sflags | SHF_STRING;
212 	shf->errno_ = 0;
213 	shf->bsize = bsize;
214 
215 	return shf;
216 }
217 
218 /* Flush and close file descriptor, free the shf structure */
219 int
shf_close(shf)220 shf_close(shf)
221 	struct shf *shf;
222 {
223 	int ret = 0;
224 
225 	if (shf->fd >= 0) {
226 		ret = shf_flush(shf);
227 		if (close(shf->fd) < 0)
228 			ret = EOF;
229 	}
230 	if (shf->flags & SHF_ALLOCS)
231 		afree(shf, shf->areap);
232 	else if (shf->flags & SHF_ALLOCB)
233 		afree(shf->buf, shf->areap);
234 
235 	return ret;
236 }
237 
238 /* Flush and close file descriptor, don't free file structure */
239 int
shf_fdclose(shf)240 shf_fdclose(shf)
241 	struct shf *shf;
242 {
243 	int ret = 0;
244 
245 	if (shf->fd >= 0) {
246 		ret = shf_flush(shf);
247 		if (close(shf->fd) < 0)
248 			ret = EOF;
249 		shf->rnleft = 0;
250 		shf->rp = shf->buf;
251 		shf->wnleft = 0;
252 		shf->fd = -1;
253 	}
254 
255 	return ret;
256 }
257 
258 /* Close a string - if it was opened for writing, it is null terminated;
259  * returns a pointer to the string and frees shf if it was allocated
260  * (does not free string if it was allocated).
261  */
262 char *
shf_sclose(shf)263 shf_sclose(shf)
264 	struct shf *shf;
265 {
266 	unsigned char *s = shf->buf;
267 
268 	/* null terminate */
269 	if (shf->flags & SHF_WR) {
270 		shf->wnleft++;
271 		shf_putc('\0', shf);
272 	}
273 	if (shf->flags & SHF_ALLOCS)
274 		afree(shf, shf->areap);
275 	return (char *) s;
276 }
277 
278 /* Flush and free file structure, don't close file descriptor */
279 int
shf_finish(shf)280 shf_finish(shf)
281 	struct shf *shf;
282 {
283 	int ret = 0;
284 
285 	if (shf->fd >= 0)
286 		ret = shf_flush(shf);
287 	if (shf->flags & SHF_ALLOCS)
288 		afree(shf, shf->areap);
289 	else if (shf->flags & SHF_ALLOCB)
290 		afree(shf->buf, shf->areap);
291 
292 	return ret;
293 }
294 
295 /* Un-read what has been read but not examined, or write what has been
296  * buffered.  Returns 0 for success, EOF for (write) error.
297  */
298 int
shf_flush(shf)299 shf_flush(shf)
300 	struct shf *shf;
301 {
302 	if (shf->flags & SHF_STRING)
303 		return (shf->flags & SHF_WR) ? EOF : 0;
304 
305 	if (shf->fd < 0)
306 		internal_errorf(1, "shf_flush: no fd");
307 
308 	if (shf->flags & SHF_ERROR) {
309 		errno = shf->errno_;
310 		return EOF;
311 	}
312 
313 	if (shf->flags & SHF_READING) {
314 		shf->flags &= ~(SHF_EOF | SHF_READING);
315 		if (shf->rnleft > 0) {
316 			lseek(shf->fd, (off_t) -shf->rnleft, 1);
317 			shf->rnleft = 0;
318 			shf->rp = shf->buf;
319 		}
320 		return 0;
321 	} else if (shf->flags & SHF_WRITING)
322 		return shf_emptybuf(shf, 0);
323 
324 	return 0;
325 }
326 
327 /* Write out any buffered data.  If currently reading, flushes the read
328  * buffer.  Returns 0 for success, EOF for (write) error.
329  */
330 static int
shf_emptybuf(shf,flags)331 shf_emptybuf(shf, flags)
332 	struct shf *shf;
333 	int flags;
334 {
335 	int ret = 0;
336 
337 	if (!(shf->flags & SHF_STRING) && shf->fd < 0)
338 		internal_errorf(1, "shf_emptybuf: no fd");
339 
340 	if (shf->flags & SHF_ERROR) {
341 		errno = shf->errno_;
342 		return EOF;
343 	}
344 
345 	if (shf->flags & SHF_READING) {
346 		if (flags & EB_READSW) /* doesn't happen */
347 			return 0;
348 		ret = shf_flush(shf);
349 		shf->flags &= ~SHF_READING;
350 	}
351 	if (shf->flags & SHF_STRING) {
352 		unsigned char	*nbuf;
353 
354 		/* Note that we assume SHF_ALLOCS is not set if SHF_ALLOCB
355 		 * is set... (changing the shf pointer could cause problems)
356 		 */
357 		if (!(flags & EB_GROW) || !(shf->flags & SHF_DYNAMIC)
358 		    || !(shf->flags & SHF_ALLOCB))
359 			return EOF;
360 		/* allocate more space for buffer */
361 		nbuf = (unsigned char *) aresize(shf->buf, shf->wbsize * 2,
362 						shf->areap);
363 		shf->rp = nbuf + (shf->rp - shf->buf);
364 		shf->wp = nbuf + (shf->wp - shf->buf);
365 		shf->rbsize += shf->wbsize;
366 		shf->wnleft += shf->wbsize;
367 		shf->wbsize *= 2;
368 		shf->buf = nbuf;
369 	} else {
370 		if (shf->flags & SHF_WRITING) {
371 			int ntowrite = shf->wp - shf->buf;
372 			unsigned char *buf = shf->buf;
373 			int n;
374 
375 			while (ntowrite > 0) {
376 				n = write(shf->fd, buf, ntowrite);
377 				if (n < 0) {
378 					if (errno == EINTR
379 					    && !(shf->flags & SHF_INTERRUPT))
380 						continue;
381 					shf->flags |= SHF_ERROR;
382 					shf->errno_ = errno;
383 					shf->wnleft = 0;
384 					if (buf != shf->buf) {
385 						/* allow a second flush
386 						 * to work */
387 						memmove(shf->buf, buf,
388 							ntowrite);
389 						shf->wp = shf->buf + ntowrite;
390 					}
391 					return EOF;
392 				}
393 				buf += n;
394 				ntowrite -= n;
395 			}
396 			if (flags & EB_READSW) {
397 				shf->wp = shf->buf;
398 				shf->wnleft = 0;
399 				shf->flags &= ~SHF_WRITING;
400 				return 0;
401 			}
402 		}
403 		shf->wp = shf->buf;
404 		shf->wnleft = shf->wbsize;
405 	}
406 	shf->flags |= SHF_WRITING;
407 
408 	return ret;
409 }
410 
411 /* Fill up a read buffer.  Returns EOF for a read error, 0 otherwise. */
412 static int
shf_fillbuf(shf)413 shf_fillbuf(shf)
414 	struct shf *shf;
415 {
416 	if (shf->flags & SHF_STRING)
417 		return 0;
418 
419 	if (shf->fd < 0)
420 		internal_errorf(1, "shf_fillbuf: no fd");
421 
422 	if (shf->flags & (SHF_EOF | SHF_ERROR)) {
423 		if (shf->flags & SHF_ERROR)
424 			errno = shf->errno_;
425 		return EOF;
426 	}
427 
428 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == EOF)
429 		return EOF;
430 
431 	shf->flags |= SHF_READING;
432 
433 	shf->rp = shf->buf;
434 	while (1) {
435 		shf->rnleft = blocking_read(shf->fd, (char *) shf->buf,
436 					    shf->rbsize);
437 		if (shf->rnleft < 0 && errno == EINTR
438 		    && !(shf->flags & SHF_INTERRUPT))
439 			continue;
440 		break;
441 	}
442 	if (shf->rnleft <= 0) {
443 		if (shf->rnleft < 0) {
444 			shf->flags |= SHF_ERROR;
445 			shf->errno_ = errno;
446 			shf->rnleft = 0;
447 			shf->rp = shf->buf;
448 			return EOF;
449 		}
450 		shf->flags |= SHF_EOF;
451 	}
452 	return 0;
453 }
454 
455 /* Seek to a new position in the file.  If writing, flushes the buffer
456  * first.  If reading, optimizes small relative seeks that stay inside the
457  * buffer.  Returns 0 for success, EOF otherwise.
458  */
459 int
shf_seek(shf,where,from)460 shf_seek(shf, where, from)
461 	struct shf *shf;
462 	off_t where;
463 	int from;
464 {
465 	if (shf->fd < 0) {
466 		errno = EINVAL;
467 		return EOF;
468 	}
469 
470 	if (shf->flags & SHF_ERROR) {
471 		errno = shf->errno_;
472 		return EOF;
473 	}
474 
475 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == EOF)
476 		return EOF;
477 
478 	if (shf->flags & SHF_READING) {
479 		if (from == SEEK_CUR &&
480 				(where < 0 ?
481 					-where >= shf->rbsize - shf->rnleft :
482 					where < shf->rnleft)) {
483 			shf->rnleft -= where;
484 			shf->rp += where;
485 			return 0;
486 		}
487 		shf->rnleft = 0;
488 		shf->rp = shf->buf;
489 	}
490 
491 	shf->flags &= ~(SHF_EOF | SHF_READING | SHF_WRITING);
492 
493 	if (lseek(shf->fd, where, from) < 0) {
494 		shf->errno_ = errno;
495 		shf->flags |= SHF_ERROR;
496 		return EOF;
497 	}
498 
499 	return 0;
500 }
501 
502 
503 /* Read a buffer from shf.  Returns the number of bytes read into buf,
504  * if no bytes were read, returns 0 if end of file was seen, EOF if
505  * a read error occurred.
506  */
507 int
shf_read(buf,bsize,shf)508 shf_read(buf, bsize, shf)
509 	char *buf;
510 	int bsize;
511 	struct shf *shf;
512 {
513 	int orig_bsize = bsize;
514 	int ncopy;
515 
516 	if (!(shf->flags & SHF_RD))
517 		internal_errorf(1, "shf_read: flags %x", shf->flags);
518 
519 	if (bsize <= 0)
520 		internal_errorf(1, "shf_read: bsize %d", bsize);
521 
522 	while (bsize > 0) {
523 		if (shf->rnleft == 0
524 		    && (shf_fillbuf(shf) == EOF || shf->rnleft == 0))
525 			break;
526 		ncopy = shf->rnleft;
527 		if (ncopy > bsize)
528 			ncopy = bsize;
529 		memcpy(buf, shf->rp, ncopy);
530 		buf += ncopy;
531 		bsize -= ncopy;
532 		shf->rp += ncopy;
533 		shf->rnleft -= ncopy;
534 	}
535 	/* Note: fread(3S) returns 0 for errors - this doesn't */
536 	return orig_bsize == bsize ? (shf_error(shf) ? EOF : 0)
537 				   : orig_bsize - bsize;
538 }
539 
540 /* Read up to a newline or EOF.  The newline is put in buf; buf is always
541  * null terminated.  Returns NULL on read error or if nothing was read before
542  * end of file, returns a pointer to the null byte in buf otherwise.
543  */
544 char *
shf_getse(buf,bsize,shf)545 shf_getse(buf, bsize, shf)
546 	char *buf;
547 	int bsize;
548 	struct shf *shf;
549 {
550 	unsigned char *end;
551 	int ncopy;
552 	char *orig_buf = buf;
553 
554 	if (!(shf->flags & SHF_RD))
555 		internal_errorf(1, "shf_getse: flags %x", shf->flags);
556 
557 	if (bsize <= 0)
558 		return (char *) 0;
559 
560 	--bsize;	/* save room for null */
561 	do {
562 		if (shf->rnleft == 0) {
563 			if (shf_fillbuf(shf) == EOF)
564 				return NULL;
565 			if (shf->rnleft == 0) {
566 				*buf = '\0';
567 				return buf == orig_buf ? NULL : buf;
568 			}
569 		}
570 		end = (unsigned char *) memchr((char *) shf->rp, '\n',
571 					     shf->rnleft);
572 		ncopy = end ? end - shf->rp + 1 : shf->rnleft;
573 		if (ncopy > bsize)
574 			ncopy = bsize;
575 		memcpy(buf, (char *) shf->rp, ncopy);
576 		shf->rp += ncopy;
577 		shf->rnleft -= ncopy;
578 		buf += ncopy;
579 		bsize -= ncopy;
580 
581 	} while (!end && bsize);
582 	*buf = '\0';
583 	return buf;
584 }
585 
586 /* Returns the char read.  Returns EOF for error and end of file. */
587 int
shf_getchar(shf)588 shf_getchar(shf)
589 	struct shf *shf;
590 {
591 	if (!(shf->flags & SHF_RD))
592 		internal_errorf(1, "shf_getchar: flags %x", shf->flags);
593 
594 	if (shf->rnleft == 0 && (shf_fillbuf(shf) == EOF || shf->rnleft == 0))
595 		return EOF;
596 	--shf->rnleft;
597 	return *shf->rp++;
598 }
599 
600 /* Put a character back in the input stream.  Returns the character if
601  * successful, EOF if there is no room.
602  */
603 int
shf_ungetc(c,shf)604 shf_ungetc(c, shf)
605 	int c;
606 	struct shf *shf;
607 {
608 	if (!(shf->flags & SHF_RD))
609 		internal_errorf(1, "shf_ungetc: flags %x", shf->flags);
610 
611 	if ((shf->flags & SHF_ERROR) || c == EOF
612 	    || (shf->rp == shf->buf && shf->rnleft))
613 		return EOF;
614 
615 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == EOF)
616 		return EOF;
617 
618 	if (shf->rp == shf->buf)
619 		shf->rp = shf->buf + shf->rbsize;
620 	if (shf->flags & SHF_STRING) {
621 		/* Can unget what was read, but not something different - we
622 		 * don't want to modify a string.
623 		 */
624 		if (shf->rp[-1] != c)
625 			return EOF;
626 		shf->flags &= ~SHF_EOF;
627 		shf->rp--;
628 		shf->rnleft++;
629 		return c;
630 	}
631 	shf->flags &= ~SHF_EOF;
632 	*--(shf->rp) = c;
633 	shf->rnleft++;
634 	return c;
635 }
636 
637 /* Write a character.  Returns the character if successful, EOF if
638  * the char could not be written.
639  */
640 int
shf_putchar(c,shf)641 shf_putchar(c, shf)
642 	int c;
643 	struct shf *shf;
644 {
645 	if (!(shf->flags & SHF_WR))
646 		internal_errorf(1, "shf_putchar: flags %x", shf->flags);
647 
648 	if (c == EOF)
649 		return EOF;
650 
651 	if (shf->flags & SHF_UNBUF) {
652 		char cc = c;
653 		int n;
654 
655 		if (shf->fd < 0)
656 			internal_errorf(1, "shf_putchar: no fd");
657 		if (shf->flags & SHF_ERROR) {
658 			errno = shf->errno_;
659 			return EOF;
660 		}
661 		while ((n = write(shf->fd, &cc, 1)) != 1)
662 			if (n < 0) {
663 				if (errno == EINTR
664 				    && !(shf->flags & SHF_INTERRUPT))
665 					continue;
666 				shf->flags |= SHF_ERROR;
667 				shf->errno_ = errno;
668 				return EOF;
669 			}
670 	} else {
671 		/* Flush deals with strings and sticky errors */
672 		if (shf->wnleft == 0 && shf_emptybuf(shf, EB_GROW) == EOF)
673 			return EOF;
674 		shf->wnleft--;
675 		*shf->wp++ = c;
676 	}
677 
678 	return c;
679 }
680 
681 /* Write a string.  Returns the length of the string if successful, EOF if
682  * the string could not be written.
683  */
684 int
shf_puts(s,shf)685 shf_puts(s, shf)
686 	const char *s;
687 	struct shf *shf;
688 {
689 	if (!s)
690 		return EOF;
691 
692 	return shf_write(s, strlen(s), shf);
693 }
694 
695 /* Write a buffer.  Returns nbytes if successful, EOF if there is an error. */
696 int
shf_write(buf,nbytes,shf)697 shf_write(buf, nbytes, shf)
698 	const char *buf;
699 	int nbytes;
700 	struct shf *shf;
701 {
702 	int orig_nbytes = nbytes;
703 	int n;
704 	int ncopy;
705 
706 	if (!(shf->flags & SHF_WR))
707 		internal_errorf(1, "shf_write: flags %x", shf->flags);
708 
709 	if (nbytes < 0)
710 		internal_errorf(1, "shf_write: nbytes %d", nbytes);
711 
712 	/* Don't buffer if buffer is empty and we're writing a large amount. */
713 	if ((ncopy = shf->wnleft)
714 	    && (shf->wp != shf->buf || nbytes < shf->wnleft))
715 	{
716 		if (ncopy > nbytes)
717 			ncopy = nbytes;
718 		memcpy(shf->wp, buf, ncopy);
719 		nbytes -= ncopy;
720 		buf += ncopy;
721 		shf->wp += ncopy;
722 		shf->wnleft -= ncopy;
723 	}
724 	if (nbytes > 0) {
725 		/* Flush deals with strings and sticky errors */
726 		if (shf_emptybuf(shf, EB_GROW) == EOF)
727 			return EOF;
728 		if (nbytes > shf->wbsize) {
729 			ncopy = nbytes;
730 			if (shf->wbsize)
731 				ncopy -= nbytes % shf->wbsize;
732 			nbytes -= ncopy;
733 			while (ncopy > 0) {
734 				n = write(shf->fd, buf, ncopy);
735 				if (n < 0) {
736 					if (errno == EINTR
737 					    && !(shf->flags & SHF_INTERRUPT))
738 						continue;
739 					shf->flags |= SHF_ERROR;
740 					shf->errno_ = errno;
741 					shf->wnleft = 0;
742 					/* Note: fwrite(3S) returns 0 for
743 					 * errors - this doesn't */
744 					return EOF;
745 				}
746 				buf += n;
747 				ncopy -= n;
748 			}
749 		}
750 		if (nbytes > 0) {
751 			memcpy(shf->wp, buf, nbytes);
752 			shf->wp += nbytes;
753 			shf->wnleft -= nbytes;
754 		}
755 	}
756 
757 	return orig_nbytes;
758 }
759 
760 int
shf_fprintf(struct shf * shf,const char * fmt,...)761 shf_fprintf(struct shf *shf, const char *fmt, ...)
762 {
763 	va_list args;
764 	int n;
765 
766 	va_start(args, fmt);
767 	n = shf_vfprintf(shf, fmt, args);
768 	va_end(args);
769 
770 	return n;
771 }
772 
773 int
shf_snprintf(char * buf,int bsize,const char * fmt,...)774 shf_snprintf(char *buf, int bsize, const char *fmt, ...)
775 {
776 	struct shf shf;
777 	va_list args;
778 	int n;
779 
780 	if (!buf || bsize <= 0)
781 		internal_errorf(1, "shf_snprintf: buf %lx, bsize %d",
782 			(long) buf, bsize);
783 
784 	shf_sopen(buf, bsize, SHF_WR, &shf);
785 	va_start(args, fmt);
786 	n = shf_vfprintf(&shf, fmt, args);
787 	va_end(args);
788 	shf_sclose(&shf); /* null terminates */
789 	return n;
790 }
791 
792 char *
shf_smprintf(const char * fmt,...)793 shf_smprintf(const char *fmt, ...)
794 {
795 	struct shf shf;
796 	va_list args;
797 
798 	shf_sopen((char *) 0, 0, SHF_WR|SHF_DYNAMIC, &shf);
799 	va_start(args, fmt);
800 	shf_vfprintf(&shf, fmt, args);
801 	va_end(args);
802 	return shf_sclose(&shf); /* null terminates */
803 }
804 
805 #undef FP  			/* if you want floating point stuff */
806 
807 #define BUF_SIZE	128
808 #define FPBUF_SIZE	(DMAXEXP+16)/* this must be >
809 				 *	MAX(DMAXEXP, log10(pow(2, DSIGNIF)))
810 				 *    + ceil(log10(DMAXEXP)) + 8 (I think).
811 				 * Since this is hard to express as a
812 				 * constant, just use a large buffer.
813 				 */
814 
815 /*
816  *	What kinda of machine we on?  Hopefully the C compiler will optimize
817  *  this out...
818  *
819  *	For shorts, we want sign extend for %d but not for %[oxu] - on 16 bit
820  *  machines it don't matter.  Assumes C compiler has converted shorts to
821  *  ints before pushing them.
822  */
823 #define POP_INT(f, s, a) (((f) & FL_LONG) ?				\
824 				va_arg((a), unsigned long)		\
825 			    :						\
826 				(sizeof(int) < sizeof(long) ?		\
827 					((s) ?				\
828 						(long) va_arg((a), int)	\
829 					    :				\
830 						va_arg((a), unsigned))	\
831 				    :					\
832 					va_arg((a), unsigned)))
833 
834 #define ABIGNUM		32000	/* big numer that will fit in a short */
835 #define LOG2_10		3.321928094887362347870319429	/* log base 2 of 10 */
836 
837 #define	FL_HASH		0x001	/* `#' seen */
838 #define FL_PLUS		0x002	/* `+' seen */
839 #define FL_RIGHT	0x004	/* `-' seen */
840 #define FL_BLANK	0x008	/* ` ' seen */
841 #define FL_SHORT	0x010	/* `h' seen */
842 #define FL_LONG		0x020	/* `l' seen */
843 #define FL_ZERO		0x040	/* `0' seen */
844 #define FL_DOT		0x080	/* '.' seen */
845 #define FL_UPPER	0x100	/* format character was uppercase */
846 #define FL_NUMBER	0x200	/* a number was formated %[douxefg] */
847 
848 
849 #ifdef FP
850 #include <math.h>
851 
852 static double
my_ceil(d)853 my_ceil(d)
854 	double	d;
855 {
856 	double		i;
857 
858 	return d - modf(d, &i) + (d < 0 ? -1 : 1);
859 }
860 #endif /* FP */
861 
862 int
shf_vfprintf(shf,fmt,args)863 shf_vfprintf(shf, fmt, args)
864 	struct shf *shf;
865 	const char *fmt;
866 	va_list args;
867 {
868 	char		c, *s;
869 	int		UNINITIALIZED(tmp);
870 	int		field, precision;
871 	int		len;
872 	int		flags;
873 	unsigned long	lnum;
874 					/* %#o produces the longest output */
875 	char		numbuf[(BITS(long) + 2) / 3 + 1];
876 	/* this stuff for dealing with the buffer */
877 	int		nwritten = 0;
878 	static char nulls[] = "(null %s)";
879 #ifdef FP
880 	/* should be in <math.h>
881 	 *  extern double frexp();
882 	 */
883 	extern char *ecvt();
884 
885 	double		fpnum;
886 	int		expo, decpt;
887 	char		style;
888 	char		fpbuf[FPBUF_SIZE];
889 #endif /* FP */
890 
891 	if (!fmt)
892 		return 0;
893 
894 	while ((c = *fmt++)) {
895 		if (c != '%') {
896 			shf_putc(c, shf);
897 			nwritten++;
898 			continue;
899 		}
900 		/*
901 		 *	This will accept flags/fields in any order - not
902 		 *  just the order specified in printf(3), but this is
903 		 *  the way _doprnt() seems to work (on bsd and sysV).
904 		 *  The only restriction is that the format character must
905 		 *  come last :-).
906 		 */
907 		flags = field = precision = 0;
908 		for ( ; (c = *fmt++) ; ) {
909 			switch (c) {
910 			case '#':
911 				flags |= FL_HASH;
912 				continue;
913 
914 			case '+':
915 				flags |= FL_PLUS;
916 				continue;
917 
918 			case '-':
919 				flags |= FL_RIGHT;
920 				continue;
921 
922 			case ' ':
923 				flags |= FL_BLANK;
924 				continue;
925 
926 			case '0':
927 				if (!(flags & FL_DOT))
928 					flags |= FL_ZERO;
929 				continue;
930 
931 			case '.':
932 				flags |= FL_DOT;
933 				precision = 0;
934 				continue;
935 
936 			case '*':
937 				tmp = va_arg(args, int);
938 				if (flags & FL_DOT)
939 					precision = tmp;
940 				else if ((field = tmp) < 0) {
941 					field = -field;
942 					flags |= FL_RIGHT;
943 				}
944 				continue;
945 
946 			case 'l':
947 				flags |= FL_LONG;
948 				continue;
949 
950 			case 'h':
951 				flags |= FL_SHORT;
952 				continue;
953 			}
954 			if (digit(c)) {
955 				tmp = c - '0';
956 				while (c = *fmt++, digit(c))
957 					tmp = tmp * 10 + c - '0';
958 				--fmt;
959 				if (tmp < 0)		/* overflow? */
960 					tmp = 0;
961 				if (flags & FL_DOT)
962 					precision = tmp;
963 				else
964 					field = tmp;
965 				continue;
966 			}
967 			break;
968 		}
969 
970 		if (precision < 0)
971 			precision = 0;
972 
973 		if (!c)		/* nasty format */
974 			break;
975 
976 		if (c >= 'A' && c <= 'Z') {
977 			flags |= FL_UPPER;
978 			c = c - 'A' + 'a';
979 		}
980 
981 		switch (c) {
982 		case 'p': /* pointer */
983 			flags &= ~(FL_LONG | FL_SHORT);
984 			if (sizeof(char *) > sizeof(int))
985 				flags |= FL_LONG; /* hope it fits.. */
986 			/* aaahhh... */
987 			/*FALLTHROUGH*/
988 		case 'd':
989 		case 'i':
990 		case 'o':
991 		case 'u':
992 		case 'x':
993 			flags |= FL_NUMBER;
994 			s = &numbuf[sizeof(numbuf)];
995 			lnum = POP_INT(flags, c == 'd', args);
996 			switch (c) {
997 			case 'd':
998 			case 'i':
999 				if (0 > (long) lnum)
1000 					lnum = - (long) lnum, tmp = 1;
1001 				else
1002 					tmp = 0;
1003 				/* aaahhhh..... */
1004 				/*FALLTHROUGH*/
1005 			case 'u':
1006 				do {
1007 					*--s = lnum % 10 + '0';
1008 					lnum /= 10;
1009 				} while (lnum);
1010 
1011 				if (c != 'u') {
1012 					if (tmp)
1013 						*--s = '-';
1014 					else if (flags & FL_PLUS)
1015 						*--s = '+';
1016 					else if (flags & FL_BLANK)
1017 						*--s = ' ';
1018 				}
1019 				break;
1020 
1021 			case 'o':
1022 				do {
1023 					*--s = (lnum & 0x7) + '0';
1024 					lnum >>= 3;
1025 				} while (lnum);
1026 
1027 				if ((flags & FL_HASH) && *s != '0')
1028 					*--s = '0';
1029 				break;
1030 
1031 			case 'p':
1032 			case 'x':
1033 			    {
1034 				const char *digits = (flags & FL_UPPER) ?
1035 						  "0123456789ABCDEF"
1036 						: "0123456789abcdef";
1037 				do {
1038 					*--s = digits[lnum & 0xf];
1039 					lnum >>= 4;
1040 				} while (lnum);
1041 
1042 				if (flags & FL_HASH) {
1043 					*--s = (flags & FL_UPPER) ? 'X' : 'x';
1044 					*--s = '0';
1045 				}
1046 			    }
1047 			}
1048 			len = &numbuf[sizeof(numbuf)] - s;
1049 			if (flags & FL_DOT) {
1050 				if (precision > len) {
1051 					field = precision;
1052 					flags |= FL_ZERO;
1053 				} else
1054 					precision = len; /* no loss */
1055 			}
1056 			break;
1057 
1058 #ifdef FP
1059 		case 'e':
1060 		case 'g':
1061 		case 'f':
1062 		    {
1063 			char *p;
1064 
1065 			/*
1066 			 *	This could probably be done better,
1067 			 *  but it seems to work.  Note that gcvt()
1068 			 *  is not used, as you cannot tell it to
1069 			 *  not strip the zeros.
1070 			 */
1071 			flags |= FL_NUMBER;
1072 			if (!(flags & FL_DOT))
1073 				precision = 6;	/* default */
1074 			/*
1075 			 *	Assumes doubles are pushed on
1076 			 *  the stack.  If this is not so, then
1077 			 *  FL_LONG/FL_SHORT should be checked.
1078 			 */
1079 			fpnum = va_arg(args, double);
1080 			s = fpbuf;
1081 			style = c;
1082 			/*
1083 			 *  This is the same as
1084 			 *	expo = ceil(log10(fpnum))
1085 			 *  but doesn't need -lm.  This is an
1086 			 *  approximation as expo is rounded up.
1087 			 */
1088 			(void) frexp(fpnum, &expo);
1089 			expo = my_ceil(expo / LOG2_10);
1090 
1091 			if (expo < 0)
1092 				expo = 0;
1093 
1094 			p = ecvt(fpnum, precision + 1 + expo,
1095 				 &decpt, &tmp);
1096 			if (c == 'g') {
1097 				if (decpt < -4 || decpt > precision)
1098 					style = 'e';
1099 				else
1100 					style = 'f';
1101 				if (decpt > 0 && (precision -= decpt) < 0)
1102 					precision = 0;
1103 			}
1104 			if (tmp)
1105 				*s++ = '-';
1106 			else if (flags & FL_PLUS)
1107 				*s++ = '+';
1108 			else if (flags & FL_BLANK)
1109 				*s++ = ' ';
1110 
1111 			if (style == 'e')
1112 				*s++ = *p++;
1113 			else {
1114 				if (decpt > 0) {
1115 					/* Overflow check - should
1116 					 * never have this problem.
1117 					 */
1118 					if (decpt >
1119 						&fpbuf[sizeof(fpbuf)]
1120 							- s - 8)
1121 						decpt =
1122 						 &fpbuf[sizeof(fpbuf)]
1123 							- s - 8;
1124 					(void) memcpy(s, p, decpt);
1125 					s += decpt;
1126 					p += decpt;
1127 				} else
1128 					*s++ = '0';
1129 			}
1130 
1131 			/* print the fraction? */
1132 			if (precision > 0) {
1133 				*s++ = '.';
1134 				/* Overflow check - should
1135 				 * never have this problem.
1136 				 */
1137 				if (precision > &fpbuf[sizeof(fpbuf)]
1138 							- s - 7)
1139 					precision =
1140 						&fpbuf[sizeof(fpbuf)]
1141 						- s - 7;
1142 				for (tmp = decpt;  tmp++ < 0 &&
1143 					    precision > 0 ; precision--)
1144 					*s++ = '0';
1145 				tmp = strlen(p);
1146 				if (precision > tmp)
1147 					precision = tmp;
1148 				/* Overflow check - should
1149 				 * never have this problem.
1150 				 */
1151 				if (precision > &fpbuf[sizeof(fpbuf)]
1152 							- s - 7)
1153 					precision =
1154 						&fpbuf[sizeof(fpbuf)]
1155 						- s - 7;
1156 				(void) memcpy(s, p, precision);
1157 				s += precision;
1158 				/*
1159 				 *	`g' format strips trailing
1160 				 *  zeros after the decimal.
1161 				 */
1162 				if (c == 'g' && !(flags & FL_HASH)) {
1163 					while (*--s == '0')
1164 						;
1165 					if (*s != '.')
1166 						s++;
1167 				}
1168 			} else if (flags & FL_HASH)
1169 				*s++ = '.';
1170 
1171 			if (style == 'e') {
1172 				*s++ = (flags & FL_UPPER) ? 'E' : 'e';
1173 				if (--decpt >= 0)
1174 					*s++ = '+';
1175 				else {
1176 					*s++ = '-';
1177 					decpt = -decpt;
1178 				}
1179 				p = &numbuf[sizeof(numbuf)];
1180 				for (tmp = 0; tmp < 2 || decpt ; tmp++) {
1181 					*--p = '0' + decpt % 10;
1182 					decpt /= 10;
1183 				}
1184 				tmp = &numbuf[sizeof(numbuf)] - p;
1185 				(void) memcpy(s, p, tmp);
1186 				s += tmp;
1187 			}
1188 
1189 			len = s - fpbuf;
1190 			s = fpbuf;
1191 			precision = len;
1192 			break;
1193 		    }
1194 #endif /* FP */
1195 
1196 		case 's':
1197 			if (!(s = va_arg(args, char *)))
1198 				s = nulls;
1199 			len = strlen(s);
1200 			break;
1201 
1202 		case 'c':
1203 			flags &= ~FL_DOT;
1204 			numbuf[0] = va_arg(args, int);
1205 			s = numbuf;
1206 			len = 1;
1207 			break;
1208 
1209 		case '%':
1210 		default:
1211 			numbuf[0] = c;
1212 			s = numbuf;
1213 			len = 1;
1214 			break;
1215 		}
1216 
1217 		/*
1218 		 *	At this point s should point to a string that is
1219 		 *  to be formatted, and len should be the length of the
1220 		 *  string.
1221 		 */
1222 		if (!(flags & FL_DOT) || len < precision)
1223 			precision = len;
1224 		if (field > precision) {
1225 			field -= precision;
1226 			if (!(flags & FL_RIGHT)) {
1227 				field = -field;
1228 				/* skip past sign or 0x when padding with 0 */
1229 				if ((flags & FL_ZERO) && (flags & FL_NUMBER)) {
1230 					if (*s == '+' || *s == '-' || *s ==' ')
1231 					{
1232 						shf_putc(*s, shf);
1233 						s++;
1234 						precision--;
1235 						nwritten++;
1236 					} else if (*s == '0') {
1237 						shf_putc(*s, shf);
1238 						s++;
1239 						nwritten++;
1240 						if (--precision > 0 &&
1241 							(*s | 0x20) == 'x')
1242 						{
1243 							shf_putc(*s, shf);
1244 							s++;
1245 							precision--;
1246 							nwritten++;
1247 						}
1248 					}
1249 					c = '0';
1250 				} else
1251 					c = flags & FL_ZERO ? '0' : ' ';
1252 				if (field < 0) {
1253 					nwritten += -field;
1254 					for ( ; field < 0 ; field++)
1255 						shf_putc(c, shf);
1256 				}
1257 			} else
1258 				c = ' ';
1259 		} else
1260 			field = 0;
1261 
1262 		if (precision > 0) {
1263 			nwritten += precision;
1264 			for ( ; precision-- > 0 ; s++)
1265 				shf_putc(*s, shf);
1266 		}
1267 		if (field > 0) {
1268 			nwritten += field;
1269 			for ( ; field > 0 ; --field)
1270 				shf_putc(c, shf);
1271 		}
1272 	}
1273 
1274 	return shf_error(shf) ? EOF : nwritten;
1275 }
1276