1 /* $NetBSD: tabs.c,v 1.6 2021/08/27 18:28:41 rillig Exp $ */
2 
3 /*-
4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Roy Marples.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 2008 \
35 The NetBSD Foundation, inc. All rights reserved.");
36 __RCSID("$NetBSD: tabs.c,v 1.6 2021/08/27 18:28:41 rillig Exp $");
37 #endif /* not lint */
38 
39 #include <sys/ioctl.h>
40 #include <sys/types.h>
41 
42 #include <ctype.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <term.h>
50 #include <unistd.h>
51 
52 #define NSTOPS 20
53 
54 struct tabspec {
55           const char *opt;
56           const char *spec;
57 };
58 static const struct tabspec tabspecs[] = {
59           {"a",     "1,10,16,36,72"},
60           {"a2",    "1,10,16,40,72"},
61           {"c",     "1,8,12,16,20,55"},
62           {"c2",    "1,6,10,14,49"},
63           {"c3",    "1,6,10,14,18,22,26,30,34,38,42,46,50,54,58,62,67"},
64           {"f",     "1,7,11,15,19,23"},
65           {"p",     "1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61"},
66           {"s",     "1,10,55"},
67           {"u",     "1,12,20,44"}
68 };
69 static const size_t ntabspecs = sizeof(tabspecs) / sizeof(tabspecs[0]);
70 
71 __dead static void
usage(void)72 usage(void)
73 {
74           fprintf(stderr,
75                     "usage: tabs [-n|-a|-a2|-c|-c2|-c3|-f|-p|-s|-u] [+m[n]]"
76                     " [-T type]\n"
77                     "       tabs [-T type] [+[n]] n1[,n2,...]\n");
78           exit(EXIT_FAILURE);
79           /* NOTREACHED */
80 }
81 
82 int
main(int argc,char ** argv)83 main(int argc, char **argv)
84 {
85           char *term, *arg, *token, *end, *tabs = NULL, *p;
86           const char *cr, *spec = NULL;
87           int i, n, inc = 8, stops[NSTOPS], nstops, last, cols, margin = 0;
88           long num = 0;
89           size_t j;
90           struct winsize ws;
91 
92           term = getenv("TERM");
93           for (i = 1; i < argc; i++) {
94                     if (argv[i][0] == '+') {
95                               arg = argv[i] + 1;
96                               if (arg[0] == 'm')
97                                         arg++;
98                               if (arg[0] == '\0')
99                                         margin = 10;
100                               else {
101                                         errno = 0;
102                                         num = strtol(arg, &end, 10);
103                                         if (errno != 0 || *end != '\0' ||
104                                             num < 0 || num > INT_MAX)
105                                                   errx(EXIT_FAILURE,
106                                                        "%s: invalid margin", arg);
107                                         margin = (int)num;
108                               }
109                               continue;
110                     }
111                     if (argv[i][0] != '-') {
112                               tabs = argv[i];
113                               break;
114                     }
115                     arg = argv[i] + 1;
116                     if (arg[0] == '\0')
117                               usage();
118                     if (arg[0] == '-' && arg[1] == '\0') {
119                               if (argv[i + 1] != NULL)
120                                         tabs = argv[i + 1];
121                               break;
122                     }
123                     if (arg[0] == 'T' && arg[1] == '\0') {
124                               term = argv[++i];
125                               if (term == NULL)
126                                         usage();
127                               continue;
128                     }
129                     if (isdigit((unsigned char)arg[0])) {
130                               if (arg[1] != '\0')
131                                         errx(EXIT_FAILURE,
132                                              "%s: invalid increment", arg);
133                               inc = arg[0] - '0';
134                               continue;
135                     }
136                     for (j = 0; j < ntabspecs; j++) {
137                               if (arg[0] == tabspecs[j].opt[0] &&
138                                   arg[1] == tabspecs[j].opt[1]) {
139                                         spec = tabspecs[j].spec;
140                                         break;
141                               }
142                     }
143                     if (j == ntabspecs)
144                               usage();
145           }
146           if (tabs == NULL && spec != NULL)
147                     tabs = strdup(spec);
148 
149           if (tabs != NULL)
150                     last = nstops = 0;
151           else
152                     nstops = -1;
153           p = tabs;
154           while ((token = strsep(&p, ", ")) != NULL) {
155                     if (*token == '\0')
156                               continue;
157                     if (nstops >= NSTOPS)
158                               errx(EXIT_FAILURE,
159                                    "too many tab stops (max %d)", NSTOPS);
160                     errno = 0;
161                     num = strtol(token, &end, 10);
162                     if (errno != 0 || *end != '\0' || num <= 0 || num > INT_MAX)
163                               errx(EXIT_FAILURE, "%s: invalid tab stop", token);
164                     n = (int)num;
165                     if (*token == '+') {
166                               if (nstops == 0)
167                                         errx(EXIT_FAILURE,
168                                              "first tab stop may not be relative");
169                               n += last;
170                     }
171                     if (last > n)
172                               errx(EXIT_FAILURE, "tab stops may not go backwards");
173                     last = stops[nstops++] = n;
174           }
175 
176           if (term == NULL)
177                     errx(EXIT_FAILURE, "no value for $TERM and -T not given");
178           if (setupterm(term, STDOUT_FILENO, NULL) != 0)
179                     err(EXIT_FAILURE, "setupterm:");
180           cr = carriage_return;
181           if (cr == NULL)
182                     cr = "\r";
183           if (clear_all_tabs == NULL)
184                     errx(EXIT_FAILURE, "terminal cannot clear tabs");
185           if (set_tab == NULL)
186                     errx(EXIT_FAILURE, "terminal cannot set tabs");
187 
188           /* Clear existing tabs */
189           putp(cr);
190           putp(clear_all_tabs);
191           putp(cr);
192 
193           if (set_lr_margin != NULL) {
194                     printf("%*s", margin, "");
195                     putp(set_lr_margin);
196           } else if (margin != 0)
197                     warnx("terminal cannot set left margin");
198 
199           if (nstops >= 0) {
200                     printf("%*s", stops[0] - 1, "");
201                     putp(set_tab);
202                     for (i = 1; i < nstops; i++) {
203                               printf("%*s", stops[i] - stops[i - 1], "");
204                               putp(set_tab);
205                     }
206           } else if (inc > 0) {
207                     cols = 0;
208                     term = getenv("COLUMNS");
209                     if (term != NULL) {
210                               errno = 0;
211                               num = strtol(term, &end, 10);
212                               if (errno == 0 && *end == '\0' &&
213                                   0 <= cols && cols <= INT_MAX)
214                                         cols = (int)num;
215                     }
216                     if (cols == 0) {
217                               if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0)
218                                         cols = ws.ws_col;
219                               else {
220                                         cols = tigetnum("cols");
221                                         if (cols == 0) {
222                                                   cols = 80;
223                                                   warnx("terminal does not specify number"
224                                                         "columns; defaulting to %d",
225                                                         cols);
226                                         }
227                               }
228                     }
229                     for (i = 0; i < cols / inc; i++) {
230                               printf("%*s", inc, "");
231                               putp(set_tab);
232                     }
233           }
234           putp(cr);
235 
236           exit(EXIT_SUCCESS);
237           /* NOTREACHED */
238 }
239