1 /* $OpenBSD: foldit.c,v 1.8 2020/08/17 18:41:23 martijn Exp $ */ 2 /* $NetBSD: foldit.c,v 1.4 1994/12/20 16:13:02 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1990, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <stdio.h> 34 35 int foldit(char *chunk, int col, int max); 36 37 int 38 foldit(char *chunk, int col, int max) 39 { 40 char *cp; 41 int first = (col != 0); 42 43 /* 44 * Keep track of column position. Insert hidden newline 45 * if this chunk puts us over the limit. 46 */ 47 again: 48 cp = chunk; 49 while (*cp) { 50 switch(*cp) { 51 case '\n': 52 case '\r': 53 col = 0; 54 break; 55 case '\t': 56 col = (col + 8) & ~07; 57 break; 58 case '\b': 59 col = col ? col - 1 : 0; 60 break; 61 default: 62 col++; 63 } 64 if (col > (max - 2)) { 65 if (!first) 66 return (col); 67 printf("\\\n"); 68 col = 0; 69 first = 0; 70 goto again; 71 } 72 cp++; 73 } 74 return (col); 75 } 76