xref: /netbsd-src/usr.bin/printf/printf.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: printf.c,v 1.50 2019/07/22 17:34:31 kre Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if !defined(BUILTIN) && !defined(SHELL)
35 __COPYRIGHT("@(#) Copyright (c) 1989, 1993\
36  The Regents of the University of California.  All rights reserved.");
37 #endif
38 #endif
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)printf.c	8.2 (Berkeley) 3/22/95";
43 #else
44 __RCSID("$NetBSD: printf.c,v 1.50 2019/07/22 17:34:31 kre Exp $");
45 #endif
46 #endif /* not lint */
47 
48 #include <sys/types.h>
49 
50 #include <ctype.h>
51 #include <err.h>
52 #include <errno.h>
53 #include <inttypes.h>
54 #include <limits.h>
55 #include <locale.h>
56 #include <stdarg.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #ifdef __GNUC__
63 #define ESCAPE '\e'
64 #else
65 #define ESCAPE 033
66 #endif
67 
68 static void	 conv_escape_str(char *, void (*)(int), int);
69 static char	*conv_escape(char *, char *, int);
70 static char	*conv_expand(const char *);
71 static char	 getchr(void);
72 static double	 getdouble(void);
73 static int	 getwidth(void);
74 static intmax_t	 getintmax(void);
75 static char	*getstr(void);
76 static char	*mklong(const char *, char);
77 static void      check_conversion(const char *, const char *);
78 static void	 usage(void);
79 
80 static void	b_count(int);
81 static void	b_output(int);
82 static size_t	b_length;
83 static char	*b_fmt;
84 
85 static int	rval;
86 static char  **gargv;
87 
88 #ifdef BUILTIN		/* csh builtin */
89 #define main progprintf
90 #endif
91 
92 #ifdef SHELL		/* sh (aka ash) builtin */
93 #define main printfcmd
94 #include "../../bin/sh/bltin/bltin.h"
95 #endif /* SHELL */
96 
97 #define PF(f, func) { \
98 	if (fieldwidth != -1) { \
99 		if (precision != -1) \
100 			error = printf(f, fieldwidth, precision, func); \
101 		else \
102 			error = printf(f, fieldwidth, func); \
103 	} else if (precision != -1) \
104 		error = printf(f, precision, func); \
105 	else \
106 		error = printf(f, func); \
107 }
108 
109 #define APF(cpp, f, func) { \
110 	if (fieldwidth != -1) { \
111 		if (precision != -1) \
112 			error = asprintf(cpp, f, fieldwidth, precision, func); \
113 		else \
114 			error = asprintf(cpp, f, fieldwidth, func); \
115 	} else if (precision != -1) \
116 		error = asprintf(cpp, f, precision, func); \
117 	else \
118 		error = asprintf(cpp, f, func); \
119 }
120 
121 #ifdef main
122 int main(int, char *[]);
123 #endif
124 
125 int
126 main(int argc, char *argv[])
127 {
128 	char *fmt, *start;
129 	int fieldwidth, precision;
130 	char nextch;
131 	char *format;
132 	char ch;
133 	int error;
134 
135 #if !defined(SHELL) && !defined(BUILTIN)
136 	(void)setlocale (LC_ALL, "");
137 #endif
138 
139 	rval = 0;	/* clear for builtin versions (avoid holdover) */
140 
141 	/*
142 	 * printf does not comply with Posix XBD 12.2 - there are no opts,
143 	 * not even the -- end of options marker.   Do not run getoot().
144 	 */
145 	if (argc > 2 && strchr(argv[1], '%') == NULL) {
146 		int o;
147 
148 		/*
149 		 * except that if there are multiple args and
150 		 * the first (the nominal format) contains no '%'
151 		 * conversions (which we will approximate as no '%'
152 		 * characters at all, conversions or not) then the
153 		 * results are unspecified, and we can do what we
154 		 * like.   So in that case, for some backward compat
155 		 * to scripts which (stupidly) do:
156 		 *	printf -- format args
157 		 * process this case the old way.
158 		 */
159 
160 		while ((o = getopt(argc, argv, "")) != -1) {
161 			switch (o) {
162 			case '?':
163 			default:
164 				usage();
165 				return 1;
166 			}
167 		}
168 		argc -= optind;
169 		argv += optind;
170 	} else {
171 		argc -= 1;	/* drop argv[0] (the program name) */
172 		argv += 1;
173 	}
174 
175 	if (argc < 1) {
176 		usage();
177 		return 1;
178 	}
179 
180 	format = *argv;
181 	gargv = ++argv;
182 
183 #define SKIP1	"#-+ 0'"
184 #define SKIP2	"0123456789"
185 	do {
186 		/*
187 		 * Basic algorithm is to scan the format string for conversion
188 		 * specifications -- once one is found, find out if the field
189 		 * width or precision is a '*'; if it is, gather up value.
190 		 * Note, format strings are reused as necessary to use up the
191 		 * provided arguments, arguments of zero/null string are
192 		 * provided to use up the format string.
193 		 */
194 
195 		/* find next format specification */
196 		for (fmt = format; (ch = *fmt++) != '\0';) {
197 			if (ch == '\\') {
198 				char c_ch;
199 				fmt = conv_escape(fmt, &c_ch, 0);
200 				putchar(c_ch);
201 				continue;
202 			}
203 			if (ch != '%' || (*fmt == '%' && ++fmt)) {
204 				(void)putchar(ch);
205 				continue;
206 			}
207 
208 			/*
209 			 * Ok - we've found a format specification,
210 			 * Save its address for a later printf().
211 			 */
212 			start = fmt - 1;
213 
214 			/* skip to field width */
215 			fmt += strspn(fmt, SKIP1);
216 			if (*fmt == '*') {
217 				fmt++;
218 				fieldwidth = getwidth();
219 			} else {
220 				fieldwidth = -1;
221 
222 				/* skip to possible '.' for precision */
223 				fmt += strspn(fmt, SKIP2);
224 			}
225 
226 			if (*fmt == '.') {
227 				 /* get following precision */
228 				fmt++;
229 				if (*fmt == '*') {
230 					fmt++;
231 					precision = getwidth();
232 				} else {
233 					precision = -1;
234 					fmt += strspn(fmt, SKIP2);
235 				}
236 			} else
237 				precision = -1;
238 
239 			ch = *fmt;
240 			if (!ch) {
241 				warnx("%s: missing format character", start);
242 				return 1;
243 			}
244 
245 			/*
246 			 * null terminate format string to we can use it
247 			 * as an argument to printf.
248 			 */
249 			nextch = fmt[1];
250 			fmt[1] = 0;
251 
252 			switch (ch) {
253 
254 			case 'B': {
255 				const char *p = conv_expand(getstr());
256 
257 				if (p == NULL)
258 					goto out;
259 				*fmt = 's';
260 				PF(start, p);
261 				if (error < 0)
262 					goto out;
263 				break;
264 			}
265 			case 'b': {
266 				/*
267 				 * There has to be a better way to do this,
268 				 * but the string we generate might have
269 				 * embedded nulls
270 				 */
271 				static char *a, *t;
272 				char *cp = getstr();
273 
274 				/* Free on entry in case shell longjumped out */
275 				if (a != NULL)
276 					free(a);
277 				a = NULL;
278 				if (t != NULL)
279 					free(t);
280 				t = NULL;
281 
282 				/* Count number of bytes we want to output */
283 				b_length = 0;
284 				conv_escape_str(cp, b_count, 0);
285 				t = malloc(b_length + 1);
286 				if (t == NULL)
287 					goto out;
288 				(void)memset(t, 'x', b_length);
289 				t[b_length] = 0;
290 
291 				/* Get printf to calculate the lengths */
292 				*fmt = 's';
293 				APF(&a, start, t);
294 				if (error == -1)
295 					goto out;
296 				b_fmt = a;
297 
298 				/* Output leading spaces and data bytes */
299 				conv_escape_str(cp, b_output, 1);
300 
301 				/* Add any trailing spaces */
302 				printf("%s", b_fmt);
303 				break;
304 			}
305 			case 'c': {
306 				char p = getchr();
307 
308 				PF(start, p);
309 				if (error < 0)
310 					goto out;
311 				break;
312 			}
313 			case 's': {
314 				char *p = getstr();
315 
316 				PF(start, p);
317 				if (error < 0)
318 					goto out;
319 				break;
320 			}
321 			case 'd':
322 			case 'i': {
323 				intmax_t p = getintmax();
324 				char *f = mklong(start, ch);
325 
326 				PF(f, p);
327 				if (error < 0)
328 					goto out;
329 				break;
330 			}
331 			case 'o':
332 			case 'u':
333 			case 'x':
334 			case 'X': {
335 				uintmax_t p = (uintmax_t)getintmax();
336 				char *f = mklong(start, ch);
337 
338 				PF(f, p);
339 				if (error < 0)
340 					goto out;
341 				break;
342 			}
343 			case 'a':
344 			case 'A':
345 			case 'e':
346 			case 'E':
347 			case 'f':
348 			case 'F':
349 			case 'g':
350 			case 'G': {
351 				double p = getdouble();
352 
353 				PF(start, p);
354 				if (error < 0)
355 					goto out;
356 				break;
357 			}
358 			case '%':
359 				/* Don't ask, but this is useful ... */
360 				if (fieldwidth == 'N' && precision == 'B')
361 					return 0;
362 				/* FALLTHROUGH */
363 			default:
364 				warnx("%s: invalid directive", start);
365 				return 1;
366 			}
367 			*fmt++ = ch;
368 			*fmt = nextch;
369 			/* escape if a \c was encountered */
370 			if (rval & 0x100)
371 				return rval & ~0x100;
372 		}
373 	} while (gargv != argv && *gargv);
374 
375 	return rval & ~0x100;
376   out:
377 	warn("print failed");
378 	return 1;
379 }
380 
381 /* helper functions for conv_escape_str */
382 
383 static void
384 /*ARGSUSED*/
385 b_count(int ch)
386 {
387 	b_length++;
388 }
389 
390 /* Output one converted character for every 'x' in the 'format' */
391 
392 static void
393 b_output(int ch)
394 {
395 	for (;;) {
396 		switch (*b_fmt++) {
397 		case 0:
398 			b_fmt--;
399 			return;
400 		case ' ':
401 			putchar(' ');
402 			break;
403 		default:
404 			putchar(ch);
405 			return;
406 		}
407 	}
408 }
409 
410 
411 /*
412  * Print SysV echo(1) style escape string
413  *	Halts processing string if a \c escape is encountered.
414  */
415 static void
416 conv_escape_str(char *str, void (*do_putchar)(int), int quiet)
417 {
418 	int value;
419 	int ch;
420 	char c;
421 
422 	while ((ch = *str++) != '\0') {
423 		if (ch != '\\') {
424 			do_putchar(ch);
425 			continue;
426 		}
427 
428 		ch = *str++;
429 		if (ch == 'c') {
430 			/* \c as in SYSV echo - abort all processing.... */
431 			rval |= 0x100;
432 			break;
433 		}
434 
435 		/*
436 		 * %b string octal constants are not like those in C.
437 		 * They start with a \0, and are followed by 0, 1, 2,
438 		 * or 3 octal digits.
439 		 */
440 		if (ch == '0') {
441 			int octnum = 0, i;
442 			for (i = 0; i < 3; i++) {
443 				if (!isdigit((unsigned char)*str) || *str > '7')
444 					break;
445 				octnum = (octnum << 3) | (*str++ - '0');
446 			}
447 			do_putchar(octnum);
448 			continue;
449 		}
450 
451 		/* \[M][^|-]C as defined by vis(3) */
452 		if (ch == 'M' && *str == '-') {
453 			do_putchar(0200 | str[1]);
454 			str += 2;
455 			continue;
456 		}
457 		if (ch == 'M' && *str == '^') {
458 			str++;
459 			value = 0200;
460 			ch = '^';
461 		} else
462 			value = 0;
463 		if (ch == '^') {
464 			ch = *str++;
465 			if (ch == '?')
466 				value |= 0177;
467 			else
468 				value |= ch & 037;
469 			do_putchar(value);
470 			continue;
471 		}
472 
473 		/* Finally test for sequences valid in the format string */
474 		str = conv_escape(str - 1, &c, quiet);
475 		do_putchar(c);
476 	}
477 }
478 
479 /*
480  * Print "standard" escape characters
481  */
482 static char *
483 conv_escape(char *str, char *conv_ch, int quiet)
484 {
485 	char value;
486 	char ch;
487 	char num_buf[4], *num_end;
488 
489 	ch = *str++;
490 
491 	switch (ch) {
492 	case '\0':
493 		if (!quiet)
494 			warnx("incomplete escape sequence");
495 		rval = 1;
496 		value = '\\';
497 		--str;
498 		break;
499 
500 	case '0': case '1': case '2': case '3':
501 	case '4': case '5': case '6': case '7':
502 		num_buf[0] = ch;
503 		ch = str[0];
504 		num_buf[1] = ch;
505 		num_buf[2] = (char)(ch != '\0' ? str[1] : '\0');
506 		num_buf[3] = '\0';
507 		value = (char)strtoul(num_buf, &num_end, 8);
508 		str += num_end  - (num_buf + 1);
509 		break;
510 
511 	case 'x':
512 		/*
513 		 * Hexadecimal character constants are not required to be
514 		 * supported (by SuS v1) because there is no consistent
515 		 * way to detect the end of the constant.
516 		 * Supporting 2 byte constants is a compromise.
517 		 */
518 		ch = str[0];
519 		num_buf[0] = ch;
520 		num_buf[1] = (char)(ch != '\0' ? str[1] : '\0');
521 		num_buf[2] = '\0';
522 		value = (char)strtoul(num_buf, &num_end, 16);
523 		str += num_end - num_buf;
524 		break;
525 
526 	case '\\':	value = '\\';	break;	/* backslash */
527 	case '\'':	value = '\'';	break;	/* single quote */
528 	case '"':	value = '"';	break;	/* double quote */
529 	case 'a':	value = '\a';	break;	/* alert */
530 	case 'b':	value = '\b';	break;	/* backspace */
531 	case 'e':	value = ESCAPE;	break;	/* escape */
532 	case 'E':	value = ESCAPE;	break;	/* escape */
533 	case 'f':	value = '\f';	break;	/* form-feed */
534 	case 'n':	value = '\n';	break;	/* newline */
535 	case 'r':	value = '\r';	break;	/* carriage-return */
536 	case 't':	value = '\t';	break;	/* tab */
537 	case 'v':	value = '\v';	break;	/* vertical-tab */
538 
539 	default:
540 		if (!quiet)
541 			warnx("unknown escape sequence `\\%c'", ch);
542 		rval = 1;
543 		value = ch;
544 		break;
545 	}
546 
547 	*conv_ch = value;
548 	return str;
549 }
550 
551 /* expand a string so that everything is printable */
552 
553 static char *
554 conv_expand(const char *str)
555 {
556 	static char *conv_str;
557 	char *cp;
558 	char ch;
559 
560 	if (conv_str)
561 		free(conv_str);
562 	/* get a buffer that is definitely large enough.... */
563 	conv_str = malloc(4 * strlen(str) + 1);
564 	if (!conv_str)
565 		return NULL;
566 	cp = conv_str;
567 
568 	while ((ch = *(const char *)str++) != '\0') {
569 		switch (ch) {
570 		/* Use C escapes for expected control characters */
571 		case '\\':	ch = '\\';	break;	/* backslash */
572 		case '\'':	ch = '\'';	break;	/* single quote */
573 		case '"':	ch = '"';	break;	/* double quote */
574 		case '\a':	ch = 'a';	break;	/* alert */
575 		case '\b':	ch = 'b';	break;	/* backspace */
576 		case ESCAPE:	ch = 'e';	break;	/* escape */
577 		case '\f':	ch = 'f';	break;	/* form-feed */
578 		case '\n':	ch = 'n';	break;	/* newline */
579 		case '\r':	ch = 'r';	break;	/* carriage-return */
580 		case '\t':	ch = 't';	break;	/* tab */
581 		case '\v':	ch = 'v';	break;	/* vertical-tab */
582 		default:
583 			/* Copy anything printable */
584 			if (isprint((unsigned char)ch)) {
585 				*cp++ = ch;
586 				continue;
587 			}
588 			/* Use vis(3) encodings for the rest */
589 			*cp++ = '\\';
590 			if (ch & 0200) {
591 				*cp++ = 'M';
592 				ch &= (char)~0200;
593 			}
594 			if (ch == 0177) {
595 				*cp++ = '^';
596 				*cp++ = '?';
597 				continue;
598 			}
599 			if (ch < 040) {
600 				*cp++ = '^';
601 				*cp++ = ch | 0100;
602 				continue;
603 			}
604 			*cp++ = '-';
605 			*cp++ = ch;
606 			continue;
607 		}
608 		*cp++ = '\\';
609 		*cp++ = ch;
610 	}
611 
612 	*cp = 0;
613 	return conv_str;
614 }
615 
616 static char *
617 mklong(const char *str, char ch)
618 {
619 	static char copy[64];
620 	size_t len;
621 
622 	len = strlen(str) + 2;
623 	if (len > sizeof copy) {
624 		warnx("format %s too complex", str);
625 		len = 4;
626 	}
627 	(void)memmove(copy, str, len - 3);
628 	copy[len - 3] = 'j';
629 	copy[len - 2] = ch;
630 	copy[len - 1] = '\0';
631 	return copy;
632 }
633 
634 static char
635 getchr(void)
636 {
637 	if (!*gargv)
638 		return 0;
639 	return **gargv++;
640 }
641 
642 static char *
643 getstr(void)
644 {
645 	static char empty[] = "";
646 	if (!*gargv)
647 		return empty;
648 	return *gargv++;
649 }
650 
651 static int
652 getwidth(void)
653 {
654 	unsigned long val;
655 	char *s, *ep;
656 
657 	s = *gargv;
658 	if (s == NULL)
659 		return 0;
660 	gargv++;
661 
662 	errno = 0;
663 	val = strtoul(s, &ep, 0);
664 	check_conversion(s, ep);
665 
666 	/* Arbitrarily 'restrict' field widths to 1Mbyte */
667 	if (val > 1 << 20) {
668 		warnx("%s: invalid field width", s);
669 		return 0;
670 	}
671 
672 	return (int)val;
673 }
674 
675 static intmax_t
676 getintmax(void)
677 {
678 	intmax_t val;
679 	char *cp, *ep;
680 
681 	cp = *gargv;
682 	if (cp == NULL)
683 		return 0;
684 	gargv++;
685 
686 	if (*cp == '\"' || *cp == '\'')
687 		return *(cp + 1);
688 
689 	errno = 0;
690 	val = strtoimax(cp, &ep, 0);
691 	check_conversion(cp, ep);
692 	return val;
693 }
694 
695 static double
696 getdouble(void)
697 {
698 	double val;
699 	char *ep;
700 
701 	if (!*gargv)
702 		return 0.0;
703 
704 	if (**gargv == '\"' || **gargv == '\'')
705 		return (double) *((*gargv++)+1);
706 
707 	errno = 0;
708 	val = strtod(*gargv, &ep);
709 	check_conversion(*gargv++, ep);
710 	return val;
711 }
712 
713 static void
714 check_conversion(const char *s, const char *ep)
715 {
716 	if (*ep) {
717 		if (ep == s)
718 			warnx("%s: expected numeric value", s);
719 		else
720 			warnx("%s: not completely converted", s);
721 		rval = 1;
722 	} else if (errno == ERANGE) {
723 		warnx("%s: %s", s, strerror(ERANGE));
724 		rval = 1;
725 	}
726 }
727 
728 static void
729 usage(void)
730 {
731 	(void)fprintf(stderr, "Usage: %s format [arg ...]\n", getprogname());
732 }
733