xref: /freebsd/usr.bin/lam/lam.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 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 /*
33  *	lam - laminate files
34  *	Author:  John Kunze, UCB
35  */
36 
37 #include <sys/capsicum.h>
38 
39 #include <capsicum_helpers.h>
40 #include <ctype.h>
41 #include <err.h>
42 #include <errno.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #define	MAXOFILES	20
49 #define	BIGBUFSIZ	5 * BUFSIZ
50 
51 static struct openfile {	/* open file structure */
52 	FILE	*fp;		/* file pointer */
53 	short	eof;		/* eof flag */
54 	short	pad;		/* pad flag for missing columns */
55 	char	eol;		/* end of line character */
56 	const char *sepstring;	/* string to print before each line */
57 	const char *format;	/* printf(3) style string spec. */
58 }	input[MAXOFILES];
59 
60 static int	morefiles;	/* set by getargs(), changed by gatherline() */
61 static int	nofinalnl;	/* normally append \n to each output line */
62 static char	line[BIGBUFSIZ];
63 static char	*linep;
64 
65 static char    *gatherline(struct openfile *);
66 static void	getargs(char *[]);
67 static char    *pad(struct openfile *);
68 static void	usage(void);
69 
70 int
71 main(int argc, char *argv[])
72 {
73 	struct	openfile *ip;
74 
75 	if (argc == 1)
76 		usage();
77 	if (caph_limit_stdio() == -1)
78 		err(1, "unable to limit stdio");
79 	getargs(argv);
80 	if (!morefiles)
81 		usage();
82 
83 	/*
84 	 * Cache NLS data, for strerror, for err(3), before entering capability
85 	 * mode.
86 	 */
87 	caph_cache_catpages();
88 	if (caph_enter() < 0)
89 		err(1, "unable to enter capability mode");
90 
91 	for (;;) {
92 		linep = line;
93 		for (ip = input; ip->fp != NULL; ip++)
94 			linep = gatherline(ip);
95 		if (!morefiles)
96 			exit(0);
97 		fputs(line, stdout);
98 		fputs(ip->sepstring, stdout);
99 		if (!nofinalnl)
100 			putchar('\n');
101 	}
102 }
103 
104 static void
105 getargs(char *av[])
106 {
107 	struct	openfile *ip = input;
108 	char *p, *c;
109 	static char fmtbuf[BUFSIZ];
110 	char *fmtp = fmtbuf;
111 	int P, S, F, T;
112 	cap_rights_t rights_ro;
113 
114 	cap_rights_init(&rights_ro, CAP_READ, CAP_FSTAT);
115 	P = S = F = T = 0;		/* capitalized options */
116 	while ((p = *++av) != NULL) {
117 		if (*p != '-' || !p[1]) {
118 			if (++morefiles >= MAXOFILES)
119 				errx(1, "too many input files");
120 			if (*p == '-')
121 				ip->fp = stdin;
122 			else if ((ip->fp = fopen(p, "r")) == NULL) {
123 				err(1, "%s", p);
124 			}
125 			if (caph_rights_limit(fileno(ip->fp), &rights_ro) < 0)
126 				err(1, "unable to limit rights on: %s", p);
127 			ip->pad = P;
128 			if (!ip->sepstring)
129 				ip->sepstring = (S ? (ip-1)->sepstring : "");
130 			if (!ip->format)
131 				ip->format = ((P || F) ? (ip-1)->format : "%s");
132 			if (!ip->eol)
133 				ip->eol = (T ? (ip-1)->eol : '\n');
134 			ip++;
135 			continue;
136 		}
137 		c = ++p;
138 		switch (tolower((unsigned char)*c)) {
139 		case 's':
140 			if (*++p || (p = *++av))
141 				ip->sepstring = p;
142 			else
143 				usage();
144 			S = (*c == 'S' ? 1 : 0);
145 			break;
146 		case 't':
147 			if (*++p || (p = *++av))
148 				ip->eol = *p;
149 			else
150 				usage();
151 			T = (*c == 'T' ? 1 : 0);
152 			nofinalnl = 1;
153 			break;
154 		case 'p':
155 			ip->pad = 1;
156 			P = (*c == 'P' ? 1 : 0);
157 			/* FALLTHROUGH */
158 		case 'f':
159 			F = (*c == 'F' ? 1 : 0);
160 			if (*++p || (p = *++av)) {
161 				fmtp += strlen(fmtp) + 1;
162 				if (fmtp >= fmtbuf + sizeof(fmtbuf))
163 					errx(1, "no more format space");
164 				/* restrict format string to only valid width formatters */
165 				if (strspn(p, "-.0123456789") != strlen(p))
166 					errx(1, "invalid format string `%s'", p);
167 				if (snprintf(fmtp, fmtbuf + sizeof(fmtbuf) - fmtp, "%%%ss", p)
168 				    >= fmtbuf + sizeof(fmtbuf) - fmtp)
169 					errx(1, "no more format space");
170 				ip->format = fmtp;
171 			}
172 			else
173 				usage();
174 			break;
175 		default:
176 			usage();
177 		}
178 	}
179 	ip->fp = NULL;
180 	if (!ip->sepstring)
181 		ip->sepstring = "";
182 }
183 
184 static char *
185 pad(struct openfile *ip)
186 {
187 	char *lp = linep;
188 
189 	strlcpy(lp, ip->sepstring, line + sizeof(line) - lp);
190 	lp += strlen(lp);
191 	if (ip->pad) {
192 		snprintf(lp, line + sizeof(line) - lp, ip->format, "");
193 		lp += strlen(lp);
194 	}
195 	return (lp);
196 }
197 
198 static char *
199 gatherline(struct openfile *ip)
200 {
201 	char s[BUFSIZ];
202 	int c;
203 	char *p;
204 	char *lp = linep;
205 	char *end = s + sizeof(s) - 1;
206 
207 	if (ip->eof)
208 		return (pad(ip));
209 	for (p = s; (c = fgetc(ip->fp)) != EOF && p < end; p++)
210 		if ((*p = c) == ip->eol)
211 			break;
212 	*p = '\0';
213 	if (c == EOF) {
214 		ip->eof = 1;
215 		if (ip->fp == stdin)
216 			fclose(stdin);
217 		morefiles--;
218 		return (pad(ip));
219 	}
220 	strlcpy(lp, ip->sepstring, line + sizeof(line) - lp);
221 	lp += strlen(lp);
222 	snprintf(lp, line + sizeof(line) - lp, ip->format, s);
223 	lp += strlen(lp);
224 	return (lp);
225 }
226 
227 static void
228 usage(void)
229 {
230 	fprintf(stderr, "%s\n%s\n",
231 "usage: lam [ -f min.max ] [ -s sepstring ] [ -t c ] file ...",
232 "       lam [ -p min.max ] [ -s sepstring ] [ -t c ] file ...");
233 	exit(1);
234 }
235