xref: /openbsd-src/bin/ksh/shf.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: shf.c,v 1.31 2016/03/20 00:01:21 krw Exp $	*/
2 
3 /*
4  *  Shell file I/O routines
5  */
6 
7 #include <sys/stat.h>
8 
9 #include <ctype.h>
10 #include <errno.h>
11 #include <fcntl.h>
12 #include <limits.h>
13 #include <stdio.h>
14 #include <string.h>
15 #include <unistd.h>
16 
17 #include "sh.h"
18 
19 /* flags to shf_emptybuf() */
20 #define EB_READSW	0x01	/* about to switch to reading */
21 #define EB_GROW		0x02	/* grow buffer if necessary (STRING+DYNAMIC) */
22 
23 /*
24  * Replacement stdio routines.  Stdio is too flakey on too many machines
25  * to be useful when you have multiple processes using the same underlying
26  * file descriptors.
27  */
28 
29 static int	shf_fillbuf(struct shf *);
30 static int	shf_emptybuf(struct shf *, int);
31 
32 /* Open a file.  First three args are for open(), last arg is flags for
33  * this package.  Returns NULL if file could not be opened, or if a dup
34  * fails.
35  */
36 struct shf *
37 shf_open(const char *name, int oflags, int mode, int sflags)
38 {
39 	struct shf *shf;
40 	int bsize = sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
41 	int fd;
42 
43 	/* Done before open so if alloca fails, fd won't be lost. */
44 	shf = alloc(sizeof(struct shf) + bsize, ATEMP);
45 	shf->areap = ATEMP;
46 	shf->buf = (unsigned char *) &shf[1];
47 	shf->bsize = bsize;
48 	shf->flags = SHF_ALLOCS;
49 	/* Rest filled in by reopen. */
50 
51 	fd = open(name, oflags, mode);
52 	if (fd < 0) {
53 		afree(shf, shf->areap);
54 		return NULL;
55 	}
56 	if ((sflags & SHF_MAPHI) && fd < FDBASE) {
57 		int nfd;
58 
59 		nfd = fcntl(fd, F_DUPFD, FDBASE);
60 		close(fd);
61 		if (nfd < 0) {
62 			afree(shf, shf->areap);
63 			return NULL;
64 		}
65 		fd = nfd;
66 	}
67 	sflags &= ~SHF_ACCMODE;
68 	sflags |= (oflags & O_ACCMODE) == O_RDONLY ? SHF_RD :
69 	    ((oflags & O_ACCMODE) == O_WRONLY ? SHF_WR : SHF_RDWR);
70 
71 	return shf_reopen(fd, sflags, shf);
72 }
73 
74 /* Set up the shf structure for a file descriptor.  Doesn't fail. */
75 struct shf *
76 shf_fdopen(int fd, int sflags, struct shf *shf)
77 {
78 	int bsize = sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
79 
80 	/* use fcntl() to figure out correct read/write flags */
81 	if (sflags & SHF_GETFL) {
82 		int flags = fcntl(fd, F_GETFL);
83 
84 		if (flags < 0)
85 			/* will get an error on first read/write */
86 			sflags |= SHF_RDWR;
87 		else {
88 			switch (flags & O_ACCMODE) {
89 			case O_RDONLY:
90 				sflags |= SHF_RD;
91 				break;
92 			case O_WRONLY:
93 				sflags |= SHF_WR;
94 				break;
95 			case O_RDWR:
96 				sflags |= SHF_RDWR;
97 				break;
98 			}
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 = alloc(bsize, ATEMP);
108 			sflags |= SHF_ALLOCB;
109 		} else
110 			shf->buf = NULL;
111 	} else {
112 		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 		fcntl(fd, F_SETFD, FD_CLOEXEC);
128 	return shf;
129 }
130 
131 /* Set up an existing shf (and buffer) to use the given fd */
132 struct shf *
133 shf_reopen(int fd, int sflags, struct shf *shf)
134 {
135 	int bsize = sflags & SHF_UNBUF ? (sflags & SHF_RD ? 1 : 0) : SHF_BSIZE;
136 
137 	/* use fcntl() to figure out correct read/write flags */
138 	if (sflags & SHF_GETFL) {
139 		int flags = fcntl(fd, F_GETFL);
140 
141 		if (flags < 0)
142 			/* will get an error on first read/write */
143 			sflags |= SHF_RDWR;
144 		else {
145 			switch (flags & O_ACCMODE) {
146 			case O_RDONLY:
147 				sflags |= SHF_RD;
148 				break;
149 			case O_WRONLY:
150 				sflags |= SHF_WR;
151 				break;
152 			case O_RDWR:
153 				sflags |= SHF_RDWR;
154 				break;
155 			}
156 		}
157 	}
158 
159 	if (!(sflags & (SHF_RD | SHF_WR)))
160 		internal_errorf(1, "shf_reopen: missing read/write");
161 	if (!shf || !shf->buf || shf->bsize < bsize)
162 		internal_errorf(1, "shf_reopen: bad shf/buf/bsize");
163 
164 	/* assumes shf->buf and shf->bsize already set up */
165 	shf->fd = fd;
166 	shf->rp = shf->wp = shf->buf;
167 	shf->rnleft = 0;
168 	shf->rbsize = bsize;
169 	shf->wnleft = 0; /* force call to shf_emptybuf() */
170 	shf->wbsize = sflags & SHF_UNBUF ? 0 : bsize;
171 	shf->flags = (shf->flags & (SHF_ALLOCS | SHF_ALLOCB)) | sflags;
172 	shf->errno_ = 0;
173 	if (sflags & SHF_CLEXEC)
174 		fcntl(fd, F_SETFD, FD_CLOEXEC);
175 	return shf;
176 }
177 
178 /* Open a string for reading or writing.  If reading, bsize is the number
179  * of bytes that can be read.  If writing, bsize is the maximum number of
180  * bytes that can be written.  If shf is not null, it is filled in and
181  * returned, if it is null, shf is allocated.  If writing and buf is null
182  * and SHF_DYNAMIC is set, the buffer is allocated (if bsize > 0, it is
183  * used for the initial size).  Doesn't fail.
184  * When writing, a byte is reserved for a trailing null - see shf_sclose().
185  */
186 struct shf *
187 shf_sopen(char *buf, int bsize, int sflags, 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 = 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
220 shf_close(struct shf *shf)
221 {
222 	int ret = 0;
223 
224 	if (shf->fd >= 0) {
225 		ret = shf_flush(shf);
226 		if (close(shf->fd) < 0)
227 			ret = EOF;
228 	}
229 	if (shf->flags & SHF_ALLOCS)
230 		afree(shf, shf->areap);
231 	else if (shf->flags & SHF_ALLOCB)
232 		afree(shf->buf, shf->areap);
233 
234 	return ret;
235 }
236 
237 /* Flush and close file descriptor, don't free file structure */
238 int
239 shf_fdclose(struct shf *shf)
240 {
241 	int ret = 0;
242 
243 	if (shf->fd >= 0) {
244 		ret = shf_flush(shf);
245 		if (close(shf->fd) < 0)
246 			ret = EOF;
247 		shf->rnleft = 0;
248 		shf->rp = shf->buf;
249 		shf->wnleft = 0;
250 		shf->fd = -1;
251 	}
252 
253 	return ret;
254 }
255 
256 /* Close a string - if it was opened for writing, it is null terminated;
257  * returns a pointer to the string and frees shf if it was allocated
258  * (does not free string if it was allocated).
259  */
260 char *
261 shf_sclose(struct shf *shf)
262 {
263 	unsigned char *s = shf->buf;
264 
265 	/* null terminate */
266 	if (shf->flags & SHF_WR) {
267 		shf->wnleft++;
268 		shf_putc('\0', shf);
269 	}
270 	if (shf->flags & SHF_ALLOCS)
271 		afree(shf, shf->areap);
272 	return (char *) s;
273 }
274 
275 /* Un-read what has been read but not examined, or write what has been
276  * buffered.  Returns 0 for success, EOF for (write) error.
277  */
278 int
279 shf_flush(struct shf *shf)
280 {
281 	if (shf->flags & SHF_STRING)
282 		return (shf->flags & SHF_WR) ? EOF : 0;
283 
284 	if (shf->fd < 0)
285 		internal_errorf(1, "shf_flush: no fd");
286 
287 	if (shf->flags & SHF_ERROR) {
288 		errno = shf->errno_;
289 		return EOF;
290 	}
291 
292 	if (shf->flags & SHF_READING) {
293 		shf->flags &= ~(SHF_EOF | SHF_READING);
294 		if (shf->rnleft > 0) {
295 			lseek(shf->fd, (off_t) -shf->rnleft, SEEK_CUR);
296 			shf->rnleft = 0;
297 			shf->rp = shf->buf;
298 		}
299 		return 0;
300 	} else if (shf->flags & SHF_WRITING)
301 		return shf_emptybuf(shf, 0);
302 
303 	return 0;
304 }
305 
306 /* Write out any buffered data.  If currently reading, flushes the read
307  * buffer.  Returns 0 for success, EOF for (write) error.
308  */
309 static int
310 shf_emptybuf(struct shf *shf, int flags)
311 {
312 	int ret = 0;
313 
314 	if (!(shf->flags & SHF_STRING) && shf->fd < 0)
315 		internal_errorf(1, "shf_emptybuf: no fd");
316 
317 	if (shf->flags & SHF_ERROR) {
318 		errno = shf->errno_;
319 		return EOF;
320 	}
321 
322 	if (shf->flags & SHF_READING) {
323 		if (flags & EB_READSW) /* doesn't happen */
324 			return 0;
325 		ret = shf_flush(shf);
326 		shf->flags &= ~SHF_READING;
327 	}
328 	if (shf->flags & SHF_STRING) {
329 		unsigned char	*nbuf;
330 
331 		/* Note that we assume SHF_ALLOCS is not set if SHF_ALLOCB
332 		 * is set... (changing the shf pointer could cause problems)
333 		 */
334 		if (!(flags & EB_GROW) || !(shf->flags & SHF_DYNAMIC) ||
335 		    !(shf->flags & SHF_ALLOCB))
336 			return EOF;
337 		/* allocate more space for buffer */
338 		nbuf = areallocarray(shf->buf, 2, shf->wbsize, shf->areap);
339 		shf->rp = nbuf + (shf->rp - shf->buf);
340 		shf->wp = nbuf + (shf->wp - shf->buf);
341 		shf->rbsize += shf->wbsize;
342 		shf->wnleft += shf->wbsize;
343 		shf->wbsize *= 2;
344 		shf->buf = nbuf;
345 	} else {
346 		if (shf->flags & SHF_WRITING) {
347 			int ntowrite = shf->wp - shf->buf;
348 			unsigned char *buf = shf->buf;
349 			int n;
350 
351 			while (ntowrite > 0) {
352 				n = write(shf->fd, buf, ntowrite);
353 				if (n < 0) {
354 					if (errno == EINTR &&
355 					    !(shf->flags & SHF_INTERRUPT))
356 						continue;
357 					shf->flags |= SHF_ERROR;
358 					shf->errno_ = errno;
359 					shf->wnleft = 0;
360 					if (buf != shf->buf) {
361 						/* allow a second flush
362 						 * to work */
363 						memmove(shf->buf, buf,
364 						    ntowrite);
365 						shf->wp = shf->buf + ntowrite;
366 					}
367 					return EOF;
368 				}
369 				buf += n;
370 				ntowrite -= n;
371 			}
372 			if (flags & EB_READSW) {
373 				shf->wp = shf->buf;
374 				shf->wnleft = 0;
375 				shf->flags &= ~SHF_WRITING;
376 				return 0;
377 			}
378 		}
379 		shf->wp = shf->buf;
380 		shf->wnleft = shf->wbsize;
381 	}
382 	shf->flags |= SHF_WRITING;
383 
384 	return ret;
385 }
386 
387 /* Fill up a read buffer.  Returns EOF for a read error, 0 otherwise. */
388 static int
389 shf_fillbuf(struct shf *shf)
390 {
391 	if (shf->flags & SHF_STRING)
392 		return 0;
393 
394 	if (shf->fd < 0)
395 		internal_errorf(1, "shf_fillbuf: no fd");
396 
397 	if (shf->flags & (SHF_EOF | SHF_ERROR)) {
398 		if (shf->flags & SHF_ERROR)
399 			errno = shf->errno_;
400 		return EOF;
401 	}
402 
403 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == EOF)
404 		return EOF;
405 
406 	shf->flags |= SHF_READING;
407 
408 	shf->rp = shf->buf;
409 	while (1) {
410 		shf->rnleft = blocking_read(shf->fd, (char *) shf->buf,
411 		    shf->rbsize);
412 		if (shf->rnleft < 0 && errno == EINTR &&
413 		    !(shf->flags & SHF_INTERRUPT))
414 			continue;
415 		break;
416 	}
417 	if (shf->rnleft <= 0) {
418 		if (shf->rnleft < 0) {
419 			shf->flags |= SHF_ERROR;
420 			shf->errno_ = errno;
421 			shf->rnleft = 0;
422 			shf->rp = shf->buf;
423 			return EOF;
424 		}
425 		shf->flags |= SHF_EOF;
426 	}
427 	return 0;
428 }
429 
430 /* Read a buffer from shf.  Returns the number of bytes read into buf,
431  * if no bytes were read, returns 0 if end of file was seen, EOF if
432  * a read error occurred.
433  */
434 int
435 shf_read(char *buf, int bsize, struct shf *shf)
436 {
437 	int orig_bsize = bsize;
438 	int ncopy;
439 
440 	if (!(shf->flags & SHF_RD))
441 		internal_errorf(1, "shf_read: flags %x", shf->flags);
442 
443 	if (bsize <= 0)
444 		internal_errorf(1, "shf_read: bsize %d", bsize);
445 
446 	while (bsize > 0) {
447 		if (shf->rnleft == 0 &&
448 		    (shf_fillbuf(shf) == EOF || shf->rnleft == 0))
449 			break;
450 		ncopy = shf->rnleft;
451 		if (ncopy > bsize)
452 			ncopy = bsize;
453 		memcpy(buf, shf->rp, ncopy);
454 		buf += ncopy;
455 		bsize -= ncopy;
456 		shf->rp += ncopy;
457 		shf->rnleft -= ncopy;
458 	}
459 	/* Note: fread(3S) returns 0 for errors - this doesn't */
460 	return orig_bsize == bsize ? (shf_error(shf) ? EOF : 0) :
461 	    orig_bsize - bsize;
462 }
463 
464 /* Read up to a newline or EOF.  The newline is put in buf; buf is always
465  * null terminated.  Returns NULL on read error or if nothing was read before
466  * end of file, returns a pointer to the null byte in buf otherwise.
467  */
468 char *
469 shf_getse(char *buf, int bsize, struct shf *shf)
470 {
471 	unsigned char *end;
472 	int ncopy;
473 	char *orig_buf = buf;
474 
475 	if (!(shf->flags & SHF_RD))
476 		internal_errorf(1, "shf_getse: flags %x", shf->flags);
477 
478 	if (bsize <= 0)
479 		return NULL;
480 
481 	--bsize;	/* save room for null */
482 	do {
483 		if (shf->rnleft == 0) {
484 			if (shf_fillbuf(shf) == EOF)
485 				return NULL;
486 			if (shf->rnleft == 0) {
487 				*buf = '\0';
488 				return buf == orig_buf ? NULL : buf;
489 			}
490 		}
491 		end = (unsigned char *) memchr((char *) shf->rp, '\n',
492 		    shf->rnleft);
493 		ncopy = end ? end - shf->rp + 1 : shf->rnleft;
494 		if (ncopy > bsize)
495 			ncopy = bsize;
496 		memcpy(buf, (char *) shf->rp, ncopy);
497 		shf->rp += ncopy;
498 		shf->rnleft -= ncopy;
499 		buf += ncopy;
500 		bsize -= ncopy;
501 	} while (!end && bsize);
502 	*buf = '\0';
503 	return buf;
504 }
505 
506 /* Returns the char read.  Returns EOF for error and end of file. */
507 int
508 shf_getchar(struct shf *shf)
509 {
510 	if (!(shf->flags & SHF_RD))
511 		internal_errorf(1, "shf_getchar: flags %x", shf->flags);
512 
513 	if (shf->rnleft == 0 && (shf_fillbuf(shf) == EOF || shf->rnleft == 0))
514 		return EOF;
515 	--shf->rnleft;
516 	return *shf->rp++;
517 }
518 
519 /* Put a character back in the input stream.  Returns the character if
520  * successful, EOF if there is no room.
521  */
522 int
523 shf_ungetc(int c, struct shf *shf)
524 {
525 	if (!(shf->flags & SHF_RD))
526 		internal_errorf(1, "shf_ungetc: flags %x", shf->flags);
527 
528 	if ((shf->flags & SHF_ERROR) || c == EOF ||
529 	    (shf->rp == shf->buf && shf->rnleft))
530 		return EOF;
531 
532 	if ((shf->flags & SHF_WRITING) && shf_emptybuf(shf, EB_READSW) == EOF)
533 		return EOF;
534 
535 	if (shf->rp == shf->buf)
536 		shf->rp = shf->buf + shf->rbsize;
537 	if (shf->flags & SHF_STRING) {
538 		/* Can unget what was read, but not something different - we
539 		 * don't want to modify a string.
540 		 */
541 		if (shf->rp[-1] != c)
542 			return EOF;
543 		shf->flags &= ~SHF_EOF;
544 		shf->rp--;
545 		shf->rnleft++;
546 		return c;
547 	}
548 	shf->flags &= ~SHF_EOF;
549 	*--(shf->rp) = c;
550 	shf->rnleft++;
551 	return c;
552 }
553 
554 /* Write a character.  Returns the character if successful, EOF if
555  * the char could not be written.
556  */
557 int
558 shf_putchar(int c, struct shf *shf)
559 {
560 	if (!(shf->flags & SHF_WR))
561 		internal_errorf(1, "shf_putchar: flags %x", shf->flags);
562 
563 	if (c == EOF)
564 		return EOF;
565 
566 	if (shf->flags & SHF_UNBUF) {
567 		char cc = c;
568 		int n;
569 
570 		if (shf->fd < 0)
571 			internal_errorf(1, "shf_putchar: no fd");
572 		if (shf->flags & SHF_ERROR) {
573 			errno = shf->errno_;
574 			return EOF;
575 		}
576 		while ((n = write(shf->fd, &cc, 1)) != 1)
577 			if (n < 0) {
578 				if (errno == EINTR &&
579 				    !(shf->flags & SHF_INTERRUPT))
580 					continue;
581 				shf->flags |= SHF_ERROR;
582 				shf->errno_ = errno;
583 				return EOF;
584 			}
585 	} else {
586 		/* Flush deals with strings and sticky errors */
587 		if (shf->wnleft == 0 && shf_emptybuf(shf, EB_GROW) == EOF)
588 			return EOF;
589 		shf->wnleft--;
590 		*shf->wp++ = c;
591 	}
592 
593 	return c;
594 }
595 
596 /* Write a string.  Returns the length of the string if successful, EOF if
597  * the string could not be written.
598  */
599 int
600 shf_puts(const char *s, struct shf *shf)
601 {
602 	if (!s)
603 		return EOF;
604 
605 	return shf_write(s, strlen(s), shf);
606 }
607 
608 /* Write a buffer.  Returns nbytes if successful, EOF if there is an error. */
609 int
610 shf_write(const char *buf, int nbytes, struct shf *shf)
611 {
612 	int orig_nbytes = nbytes;
613 	int n;
614 	int ncopy;
615 
616 	if (!(shf->flags & SHF_WR))
617 		internal_errorf(1, "shf_write: flags %x", shf->flags);
618 
619 	if (nbytes < 0)
620 		internal_errorf(1, "shf_write: nbytes %d", nbytes);
621 
622 	/* Don't buffer if buffer is empty and we're writting a large amount. */
623 	if ((ncopy = shf->wnleft) &&
624 	    (shf->wp != shf->buf || nbytes < shf->wnleft)) {
625 		if (ncopy > nbytes)
626 			ncopy = nbytes;
627 		memcpy(shf->wp, buf, ncopy);
628 		nbytes -= ncopy;
629 		buf += ncopy;
630 		shf->wp += ncopy;
631 		shf->wnleft -= ncopy;
632 	}
633 	if (nbytes > 0) {
634 		/* Flush deals with strings and sticky errors */
635 		if (shf_emptybuf(shf, EB_GROW) == EOF)
636 			return EOF;
637 		if (nbytes > shf->wbsize) {
638 			ncopy = nbytes;
639 			if (shf->wbsize)
640 				ncopy -= nbytes % shf->wbsize;
641 			nbytes -= ncopy;
642 			while (ncopy > 0) {
643 				n = write(shf->fd, buf, ncopy);
644 				if (n < 0) {
645 					if (errno == EINTR &&
646 					    !(shf->flags & SHF_INTERRUPT))
647 						continue;
648 					shf->flags |= SHF_ERROR;
649 					shf->errno_ = errno;
650 					shf->wnleft = 0;
651 					/* Note: fwrite(3S) returns 0 for
652 					 * errors - this doesn't */
653 					return EOF;
654 				}
655 				buf += n;
656 				ncopy -= n;
657 			}
658 		}
659 		if (nbytes > 0) {
660 			memcpy(shf->wp, buf, nbytes);
661 			shf->wp += nbytes;
662 			shf->wnleft -= nbytes;
663 		}
664 	}
665 
666 	return orig_nbytes;
667 }
668 
669 int
670 shf_fprintf(struct shf *shf, const char *fmt, ...)
671 {
672 	va_list args;
673 	int n;
674 
675 	va_start(args, fmt);
676 	n = shf_vfprintf(shf, fmt, args);
677 	va_end(args);
678 
679 	return n;
680 }
681 
682 int
683 shf_snprintf(char *buf, int bsize, const char *fmt, ...)
684 {
685 	struct shf shf;
686 	va_list args;
687 	int n;
688 
689 	if (!buf || bsize <= 0)
690 		internal_errorf(1, "shf_snprintf: buf %lx, bsize %d",
691 			(long) buf, bsize);
692 
693 	shf_sopen(buf, bsize, SHF_WR, &shf);
694 	va_start(args, fmt);
695 	n = shf_vfprintf(&shf, fmt, args);
696 	va_end(args);
697 	shf_sclose(&shf); /* null terminates */
698 	return n;
699 }
700 
701 char *
702 shf_smprintf(const char *fmt, ...)
703 {
704 	struct shf shf;
705 	va_list args;
706 
707 	shf_sopen(NULL, 0, SHF_WR|SHF_DYNAMIC, &shf);
708 	va_start(args, fmt);
709 	shf_vfprintf(&shf, fmt, args);
710 	va_end(args);
711 	return shf_sclose(&shf); /* null terminates */
712 }
713 
714 #define	FL_HASH		0x001	/* `#' seen */
715 #define FL_PLUS		0x002	/* `+' seen */
716 #define FL_RIGHT	0x004	/* `-' seen */
717 #define FL_BLANK	0x008	/* ` ' seen */
718 #define FL_SHORT	0x010	/* `h' seen */
719 #define FL_LONG		0x020	/* `l' seen */
720 #define FL_LLONG	0x040	/* `ll' seen */
721 #define FL_ZERO		0x080	/* `0' seen */
722 #define FL_DOT		0x100	/* '.' seen */
723 #define FL_UPPER	0x200	/* format character was uppercase */
724 #define FL_NUMBER	0x400	/* a number was formated %[douxefg] */
725 
726 int
727 shf_vfprintf(struct shf *shf, const char *fmt, va_list args)
728 {
729 	char		c, *s;
730 	int		tmp = 0;
731 	int		field, precision;
732 	int		len;
733 	int		flags;
734 	unsigned long long	llnum;
735 					/* %#o produces the longest output */
736 	char		numbuf[(BITS(long long) + 2) / 3 + 1];
737 	/* this stuff for dealing with the buffer */
738 	int		nwritten = 0;
739 
740 	if (!fmt)
741 		return 0;
742 
743 	while ((c = *fmt++)) {
744 		if (c != '%') {
745 			shf_putc(c, shf);
746 			nwritten++;
747 			continue;
748 		}
749 		/*
750 		 *	This will accept flags/fields in any order - not
751 		 *  just the order specified in printf(3), but this is
752 		 *  the way _doprnt() seems to work (on bsd and sysV).
753 		 *  The only restriction is that the format character must
754 		 *  come last :-).
755 		 */
756 		flags = field = precision = 0;
757 		for ( ; (c = *fmt++) ; ) {
758 			switch (c) {
759 			case '#':
760 				flags |= FL_HASH;
761 				continue;
762 
763 			case '+':
764 				flags |= FL_PLUS;
765 				continue;
766 
767 			case '-':
768 				flags |= FL_RIGHT;
769 				continue;
770 
771 			case ' ':
772 				flags |= FL_BLANK;
773 				continue;
774 
775 			case '0':
776 				if (!(flags & FL_DOT))
777 					flags |= FL_ZERO;
778 				continue;
779 
780 			case '.':
781 				flags |= FL_DOT;
782 				precision = 0;
783 				continue;
784 
785 			case '*':
786 				tmp = va_arg(args, int);
787 				if (flags & FL_DOT)
788 					precision = tmp;
789 				else if ((field = tmp) < 0) {
790 					field = -field;
791 					flags |= FL_RIGHT;
792 				}
793 				continue;
794 
795 			case 'l':
796 				if (*fmt == 'l') {
797 					fmt++;
798 					flags |= FL_LLONG;
799 				} else
800 					flags |= FL_LONG;
801 				continue;
802 
803 			case 'h':
804 				flags |= FL_SHORT;
805 				continue;
806 			}
807 			if (digit(c)) {
808 				tmp = c - '0';
809 				while (c = *fmt++, digit(c))
810 					tmp = tmp * 10 + c - '0';
811 				--fmt;
812 				if (tmp < 0)		/* overflow? */
813 					tmp = 0;
814 				if (flags & FL_DOT)
815 					precision = tmp;
816 				else
817 					field = tmp;
818 				continue;
819 			}
820 			break;
821 		}
822 
823 		if (precision < 0)
824 			precision = 0;
825 
826 		if (!c)		/* nasty format */
827 			break;
828 
829 		if (c >= 'A' && c <= 'Z') {
830 			flags |= FL_UPPER;
831 			c = c - 'A' + 'a';
832 		}
833 
834 		switch (c) {
835 		case 'p': /* pointer */
836 			flags &= ~(FL_LLONG | FL_SHORT);
837 			flags |= FL_LONG;
838 			/* aaahhh... */
839 		case 'd':
840 		case 'i':
841 		case 'o':
842 		case 'u':
843 		case 'x':
844 			flags |= FL_NUMBER;
845 			s = &numbuf[sizeof(numbuf)];
846 			if (flags & FL_LLONG)
847 				llnum = va_arg(args, unsigned long long);
848 			else if (flags & FL_LONG) {
849 				if (c == 'd' || c == 'i')
850 					llnum = va_arg(args, long);
851 				else
852 					llnum = va_arg(args, unsigned long);
853 			} else {
854 				if (c == 'd' || c == 'i')
855 					llnum = va_arg(args, int);
856 				else
857 					llnum = va_arg(args, unsigned int);
858 			}
859 			switch (c) {
860 			case 'd':
861 			case 'i':
862 				if (0 > (long long) llnum)
863 					llnum = - (long long) llnum, tmp = 1;
864 				else
865 					tmp = 0;
866 				/* aaahhhh..... */
867 
868 			case 'u':
869 				do {
870 					*--s = llnum % 10 + '0';
871 					llnum /= 10;
872 				} while (llnum);
873 
874 				if (c != 'u') {
875 					if (tmp)
876 						*--s = '-';
877 					else if (flags & FL_PLUS)
878 						*--s = '+';
879 					else if (flags & FL_BLANK)
880 						*--s = ' ';
881 				}
882 				break;
883 
884 			case 'o':
885 				do {
886 					*--s = (llnum & 0x7) + '0';
887 					llnum >>= 3;
888 				} while (llnum);
889 
890 				if ((flags & FL_HASH) && *s != '0')
891 					*--s = '0';
892 				break;
893 
894 			case 'p':
895 			case 'x':
896 			    {
897 				const char *digits = (flags & FL_UPPER) ?
898 				    "0123456789ABCDEF" :
899 				    "0123456789abcdef";
900 				do {
901 					*--s = digits[llnum & 0xf];
902 					llnum >>= 4;
903 				} while (llnum);
904 
905 				if (flags & FL_HASH) {
906 					*--s = (flags & FL_UPPER) ? 'X' : 'x';
907 					*--s = '0';
908 				}
909 			    }
910 			}
911 			len = &numbuf[sizeof(numbuf)] - s;
912 			if (flags & FL_DOT) {
913 				if (precision > len) {
914 					field = precision;
915 					flags |= FL_ZERO;
916 				} else
917 					precision = len; /* no loss */
918 			}
919 			break;
920 
921 		case 's':
922 			if (!(s = va_arg(args, char *)))
923 				s = "(null %s)";
924 			len = strlen(s);
925 			break;
926 
927 		case 'c':
928 			flags &= ~FL_DOT;
929 			numbuf[0] = va_arg(args, int);
930 			s = numbuf;
931 			len = 1;
932 			break;
933 
934 		case '%':
935 		default:
936 			numbuf[0] = c;
937 			s = numbuf;
938 			len = 1;
939 			break;
940 		}
941 
942 		/*
943 		 *	At this point s should point to a string that is
944 		 *  to be formatted, and len should be the length of the
945 		 *  string.
946 		 */
947 		if (!(flags & FL_DOT) || len < precision)
948 			precision = len;
949 		if (field > precision) {
950 			field -= precision;
951 			if (!(flags & FL_RIGHT)) {
952 				field = -field;
953 				/* skip past sign or 0x when padding with 0 */
954 				if ((flags & FL_ZERO) && (flags & FL_NUMBER)) {
955 					if (*s == '+' || *s == '-' || *s ==' ') {
956 						shf_putc(*s, shf);
957 						s++;
958 						precision--;
959 						nwritten++;
960 					} else if (*s == '0') {
961 						shf_putc(*s, shf);
962 						s++;
963 						nwritten++;
964 						if (--precision > 0 &&
965 						    (*s | 0x20) == 'x') {
966 							shf_putc(*s, shf);
967 							s++;
968 							precision--;
969 							nwritten++;
970 						}
971 					}
972 					c = '0';
973 				} else
974 					c = flags & FL_ZERO ? '0' : ' ';
975 				if (field < 0) {
976 					nwritten += -field;
977 					for ( ; field < 0 ; field++)
978 						shf_putc(c, shf);
979 				}
980 			} else
981 				c = ' ';
982 		} else
983 			field = 0;
984 
985 		if (precision > 0) {
986 			nwritten += precision;
987 			for ( ; precision-- > 0 ; s++)
988 				shf_putc(*s, shf);
989 		}
990 		if (field > 0) {
991 			nwritten += field;
992 			for ( ; field > 0 ; --field)
993 				shf_putc(c, shf);
994 		}
995 	}
996 
997 	return shf_error(shf) ? EOF : nwritten;
998 }
999