Home | History | Annotate | Line # | Download | only in expand
expand.c revision 1.12.6.1 
      1 /*	$NetBSD: expand.c,v 1.12.6.1 2009/05/13 19:19:49 jym Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1980, 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 __COPYRIGHT("@(#) Copyright (c) 1980, 1993\
     35  The Regents of the University of California.  All rights reserved.");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)expand.c	8.1 (Berkeley) 6/9/93";
     41 #endif
     42 __RCSID("$NetBSD: expand.c,v 1.12.6.1 2009/05/13 19:19:49 jym Exp $");
     43 #endif /* not lint */
     44 
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <ctype.h>
     48 #include <unistd.h>
     49 #include <err.h>
     50 
     51 /*
     52  * expand - expand tabs to equivalent spaces
     53  */
     54 size_t	nstops;
     55 size_t	tabstops[100];
     56 
     57 static	void	getstops(const char *);
     58 	int	main(int, char **);
     59 static	void	usage(void) __dead;
     60 
     61 int
     62 main(int argc, char *argv[])
     63 {
     64 	int c;
     65 	size_t n, column;
     66 
     67 	setprogname(argv[0]);
     68 
     69 	/* handle obsolete syntax */
     70 	while (argc > 1 &&
     71 	    argv[1][0] == '-' && isdigit((unsigned char)argv[1][1])) {
     72 		getstops(&argv[1][1]);
     73 		argc--; argv++;
     74 	}
     75 
     76 	while ((c = getopt (argc, argv, "t:")) != -1) {
     77 		switch (c) {
     78 		case 't':
     79 			getstops(optarg);
     80 			break;
     81 		case '?':
     82 		default:
     83 			usage();
     84 			/* NOTREACHED */
     85 		}
     86 	}
     87 	argc -= optind;
     88 	argv += optind;
     89 
     90 	do {
     91 		if (argc > 0) {
     92 			if (freopen(argv[0], "r", stdin) == NULL)
     93 				err(EXIT_FAILURE, "Cannot open `%s'", argv[0]);
     94 			argc--, argv++;
     95 		}
     96 		column = 0;
     97 		while ((c = getchar()) != EOF) {
     98 			switch (c) {
     99 			case '\t':
    100 				if (nstops == 0) {
    101 					do {
    102 						putchar(' ');
    103 						column++;
    104 					} while (column & 07);
    105 					continue;
    106 				}
    107 				if (nstops == 1) {
    108 					do {
    109 						putchar(' ');
    110 						column++;
    111 					} while (((column - 1) % tabstops[0])
    112 					    != (tabstops[0] - 1));
    113 					continue;
    114 				}
    115 				for (n = 0; n < nstops; n++)
    116 					if (tabstops[n] > column)
    117 						break;
    118 				if (n == nstops) {
    119 					putchar(' ');
    120 					column++;
    121 					continue;
    122 				}
    123 				while (column < tabstops[n]) {
    124 					putchar(' ');
    125 					column++;
    126 				}
    127 				continue;
    128 
    129 			case '\b':
    130 				if (column)
    131 					column--;
    132 				putchar('\b');
    133 				continue;
    134 
    135 			default:
    136 				putchar(c);
    137 				column++;
    138 				continue;
    139 
    140 			case '\n':
    141 				putchar(c);
    142 				column = 0;
    143 				continue;
    144 			}
    145 		}
    146 	} while (argc > 0);
    147 	return EXIT_SUCCESS;
    148 }
    149 
    150 static void
    151 getstops(const char *spec)
    152 {
    153 	int i;
    154 	const char *cp = spec;
    155 
    156 	nstops = 0;
    157 	for (;;) {
    158 		i = 0;
    159 		while (*cp >= '0' && *cp <= '9')
    160 			i = i * 10 + *cp++ - '0';
    161 		if (i <= 0 || i > 256)
    162 			errx(EXIT_FAILURE, "Too large tab stop spec `%d'", i);
    163 		if (nstops > 0 && (size_t)i <= tabstops[nstops-1])
    164 			errx(EXIT_FAILURE, "Out of order tabstop spec `%d'", i);
    165 		if (nstops == sizeof(tabstops) / sizeof(tabstops[0]) - 1)
    166 			errx(EXIT_FAILURE, "Too many tabstops");
    167 		tabstops[nstops++] = i;
    168 		if (*cp == '\0')
    169 			break;
    170 		if (*cp != ',' && *cp != ' ')
    171 			errx(EXIT_FAILURE, "Illegal tab stop spec `%s'", spec);
    172 		cp++;
    173 	}
    174 }
    175 
    176 static void
    177 usage(void)
    178 {
    179 
    180 	(void)fprintf(stderr, "Usage: %s [-t tablist] [file ...]\n",
    181 	    getprogname());
    182 	exit(EXIT_FAILURE);
    183 }
    184