1 /* $OpenBSD: colrm.c,v 1.12 2016/01/18 20:31:36 schwarze Exp $ */ 2 /* $NetBSD: colrm.c,v 1.4 1995/09/02 05:51:37 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1991, 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 <sys/types.h> 34 35 #include <err.h> 36 #include <errno.h> 37 #include <limits.h> 38 #include <locale.h> 39 #include <stdio.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <unistd.h> 43 #include <wchar.h> 44 45 #define TAB 8 46 47 void usage(void); 48 49 int 50 main(int argc, char *argv[]) 51 { 52 char *line, *p; 53 ssize_t linesz; 54 wchar_t wc; 55 u_long column, newcol, start, stop; 56 int ch, len, width; 57 58 setlocale(LC_ALL, ""); 59 60 if (pledge("stdio", NULL) == -1) 61 err(1, "pledge"); 62 63 while ((ch = getopt(argc, argv, "")) != -1) 64 switch(ch) { 65 case '?': 66 default: 67 usage(); 68 } 69 argc -= optind; 70 argv += optind; 71 72 start = stop = 0; 73 switch(argc) { 74 case 2: 75 stop = strtol(argv[1], &p, 10); 76 if (stop <= 0 || *p) 77 errx(1, "illegal column -- %s", argv[1]); 78 /* FALLTHROUGH */ 79 case 1: 80 start = strtol(argv[0], &p, 10); 81 if (start <= 0 || *p) 82 errx(1, "illegal column -- %s", argv[0]); 83 break; 84 case 0: 85 break; 86 default: 87 usage(); 88 } 89 90 if (stop && start > stop) 91 err(1, "illegal start and stop columns"); 92 93 line = NULL; 94 while (getline(&line, &linesz, stdin) != -1) { 95 column = 0; 96 width = 0; 97 for (p = line; *p != '\0'; p += len) { 98 len = 1; 99 switch (*p) { 100 case '\n': 101 putchar('\n'); 102 continue; 103 case '\b': 104 /* 105 * Pass it through if the previous character 106 * was in scope, still represented by the 107 * current value of "column". 108 * Allow an optional second backspace 109 * after a double-width character. 110 */ 111 if (start == 0 || column < start || 112 (stop > 0 && 113 column > stop + (width > 1))) { 114 putchar('\b'); 115 if (width > 1 && p[1] == '\b') 116 putchar('\b'); 117 } 118 if (width > 1 && p[1] == '\b') 119 p++; 120 column -= width; 121 continue; 122 case '\t': 123 newcol = (column + TAB) & ~(TAB - 1); 124 if (start == 0 || newcol < start) { 125 putchar('\t'); 126 column = newcol; 127 } else 128 /* 129 * Expand tabs that intersect or 130 * follow deleted columns. 131 */ 132 while (column < newcol) 133 if (++column < start || 134 (stop > 0 && 135 column > stop)) 136 putchar(' '); 137 continue; 138 default: 139 break; 140 } 141 142 /* 143 * Handle the three cases of invalid bytes, 144 * non-printable, and printable characters. 145 */ 146 147 if ((len = mbtowc(&wc, p, MB_CUR_MAX)) == -1) { 148 (void)mbtowc(NULL, NULL, MB_CUR_MAX); 149 len = 1; 150 width = 1; 151 } else if ((width = wcwidth(wc)) == -1) 152 width = 1; 153 154 /* 155 * If the character completely fits before or 156 * after the cut, keep it; otherwise, skip it. 157 */ 158 159 if ((start == 0 || column + width < start || 160 (stop > 0 && column + (width > 0) > stop))) 161 fwrite(p, 1, len, stdout); 162 163 /* 164 * If the cut cuts the character in half 165 * and no backspace follows, 166 * print a blank for correct columnation. 167 */ 168 169 else if (width > 1 && p[len] != '\b' && 170 (start == 0 || column + 1 < start || 171 (stop > 0 && column + width > stop))) 172 putchar(' '); 173 174 column += width; 175 } 176 } 177 if (ferror(stdin)) 178 err(1, "stdin"); 179 if (ferror(stdout)) 180 err(1, "stdout"); 181 return 0; 182 } 183 184 void 185 usage(void) 186 { 187 (void)fprintf(stderr, "usage: colrm [start [stop]]\n"); 188 exit(1); 189 } 190