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unexpand.c revision 1.13 
      1 /*	$NetBSD: unexpand.c,v 1.13 2008/07/21 14:19:27 lukem 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[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
     41 #endif
     42 __RCSID("$NetBSD: unexpand.c,v 1.13 2008/07/21 14:19:27 lukem Exp $");
     43 #endif /* not lint */
     44 
     45 /*
     46  * unexpand - put tabs into a file replacing blanks
     47  */
     48 #include <stdio.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <unistd.h>
     52 #include <errno.h>
     53 #include <err.h>
     54 
     55 char	genbuf[BUFSIZ];
     56 char	linebuf[BUFSIZ];
     57 
     58 int	main(int, char **);
     59 void	tabify(int, uint);
     60 
     61 int
     62 main(int argc, char **argv)
     63 {
     64 	int all, c;
     65 	uint tabsize;
     66 	ulong l;
     67 	char *ep;
     68 
     69 	setprogname(argv[0]);
     70 
     71 	all = 0;
     72 	tabsize = 8;
     73 	while ((c = getopt(argc, argv, "at:")) != -1) {
     74 		switch (c) {
     75 		case 'a':
     76 			all++;
     77 			break;
     78 		case 't':
     79 			errno = 0;
     80 			l = strtoul(optarg, &ep, 0);
     81 			/*
     82 			 * If every input char is a tab, the line length
     83 			 * must not exceed maxuint.
     84 			 */
     85 			tabsize = (int)l * BUFSIZ;
     86 			tabsize /= BUFSIZ;
     87 			if (*ep != 0 || errno != 0 || (ulong)tabsize != l)
     88 				errx(EXIT_FAILURE, "Invalid tabstop \"%s\"",
     89 				    optarg);
     90 			break;
     91 		case '?':
     92 		default:
     93 			fprintf(stderr, "usage: %s [-a] [-t tabstop] [file ...]\n",
     94 				getprogname());
     95 			exit(EXIT_FAILURE);
     96 			/* NOTREACHED */
     97 		}
     98 	}
     99 	argc -= optind;
    100 	argv += optind;
    101 
    102 	do {
    103 		if (argc > 0) {
    104 			if (freopen(argv[0], "r", stdin) == NULL) {
    105 				perror(argv[0]);
    106 				exit(EXIT_FAILURE);
    107 			}
    108 			argc--, argv++;
    109 		}
    110 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
    111 			tabify(all, tabsize);
    112 			printf("%s", linebuf);
    113 		}
    114 	} while (argc > 0);
    115 	exit(EXIT_SUCCESS);
    116 	/* NOTREACHED */
    117 }
    118 
    119 void
    120 tabify(int all, uint tabsize)
    121 {
    122 	char *cp, *dp;
    123 	uint dcol;
    124 	uint ocol;
    125 	uint tcol;
    126 
    127 	ocol = 0;
    128 	dcol = 0;
    129 	cp = genbuf, dp = linebuf;
    130 	for (;;) {
    131 		switch (*cp) {
    132 
    133 		case ' ':
    134 			dcol++;
    135 			break;
    136 
    137 		case '\t':
    138 			dcol = (dcol + tabsize) / tabsize * tabsize;
    139 			break;
    140 
    141 		default:
    142 			if (dcol > ocol + 1) {
    143 				tcol = (ocol + tabsize) / tabsize * tabsize;
    144 				while (tcol <= dcol) {
    145 					*dp++ = '\t';
    146 					ocol = tcol;
    147 					tcol += tabsize;
    148 				}
    149 			}
    150 			while (ocol < dcol) {
    151 				*dp++ = ' ';
    152 				ocol++;
    153 			}
    154 			if (*cp == 0 || all == 0) {
    155 				strlcpy(dp, cp,
    156 				    sizeof(linebuf) - (dp - linebuf));
    157 				return;
    158 			}
    159 			*dp++ = *cp;
    160 			dcol = ++ocol;
    161 		}
    162 		cp++;
    163 	}
    164 }
    165