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unexpand.c revision 1.10 
      1 /*	$NetBSD: unexpand.c,v 1.10 2003/04/08 10:47:03 dsl 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) Copyright (c) 1980, 1993\n\
     39 	The Regents of the University of California.  All rights reserved.\n");
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)unexpand.c	8.1 (Berkeley) 6/6/93";
     45 #endif
     46 __RCSID("$NetBSD: unexpand.c,v 1.10 2003/04/08 10:47:03 dsl Exp $");
     47 #endif /* not lint */
     48 
     49 /*
     50  * unexpand - put tabs into a file replacing blanks
     51  */
     52 #include <stdio.h>
     53 #include <stdlib.h>
     54 #include <string.h>
     55 #include <unistd.h>
     56 #include <errno.h>
     57 #include <err.h>
     58 
     59 char	genbuf[BUFSIZ];
     60 char	linebuf[BUFSIZ];
     61 
     62 int	main(int, char **);
     63 void	tabify(int, uint);
     64 
     65 int
     66 main(int argc, char **argv)
     67 {
     68 	int all, c;
     69 	uint tabsize;
     70 	ulong l;
     71 	char *ep;
     72 
     73 	setprogname(argv[0]);
     74 
     75 	all = 0;
     76 	tabsize = 8;
     77 	while ((c = getopt(argc, argv, "at:")) != -1) {
     78 		switch (c) {
     79 		case 'a':
     80 			all++;
     81 			break;
     82 		case 't':
     83 			errno = 0;
     84 			l = strtoul(optarg, &ep, 0);
     85 			/*
     86 			 * If every input char is a tab, the line length
     87 			 * must not exceed maxuint.
     88 			 */
     89 			tabsize = (int)l * BUFSIZ;
     90 			tabsize /= BUFSIZ;
     91 			if (*ep != 0 || errno != 0 || (ulong)tabsize != l)
     92 				errx(EXIT_FAILURE, "Invalid tabstop \"%s\"",
     93 				    optarg);
     94 			break;
     95 		case '?':
     96 		default:
     97 			fprintf(stderr, "usage: %s [-a] [-t tabstop] [file ...]\n",
     98 				getprogname());
     99 			exit(EXIT_FAILURE);
    100 			/* NOTREACHED */
    101 		}
    102 	}
    103 	argc -= optind;
    104 	argv += optind;
    105 
    106 	do {
    107 		if (argc > 0) {
    108 			if (freopen(argv[0], "r", stdin) == NULL) {
    109 				perror(argv[0]);
    110 				exit(EXIT_FAILURE);
    111 			}
    112 			argc--, argv++;
    113 		}
    114 		while (fgets(genbuf, BUFSIZ, stdin) != NULL) {
    115 			tabify(all, tabsize);
    116 			printf("%s", linebuf);
    117 		}
    118 	} while (argc > 0);
    119 	exit(EXIT_SUCCESS);
    120 	/* NOTREACHED */
    121 }
    122 
    123 void
    124 tabify(int all, uint tabsize)
    125 {
    126 	char *cp, *dp;
    127 	uint dcol;
    128 	uint ocol;
    129 	uint tcol;
    130 
    131 	ocol = 0;
    132 	dcol = 0;
    133 	cp = genbuf, dp = linebuf;
    134 	for (;;) {
    135 		switch (*cp) {
    136 
    137 		case ' ':
    138 			dcol++;
    139 			break;
    140 
    141 		case '\t':
    142 			dcol = (dcol + tabsize) / tabsize * tabsize;
    143 			break;
    144 
    145 		default:
    146 			if (dcol > ocol + 1) {
    147 				tcol = (ocol + tabsize) / tabsize * tabsize;
    148 				while (tcol <= dcol) {
    149 					*dp++ = '\t';
    150 					ocol = tcol;
    151 					tcol += tabsize;
    152 				}
    153 			}
    154 			while (ocol < dcol) {
    155 				*dp++ = ' ';
    156 				ocol++;
    157 			}
    158 			if (*cp == 0 || all == 0) {
    159 				strcpy(dp, cp);
    160 				return;
    161 			}
    162 			*dp++ = *cp;
    163 			dcol = ++ocol;
    164 		}
    165 		cp++;
    166 	}
    167 }
    168