xref: /freebsd/usr.bin/locate/bigram/locate.bigram.c (revision 00ad40d70a67f0dd8c18d30ff3d0290f924b2ac8)
1 /*
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1995-2022 Wolfram Schneider <wosch@FreeBSD.org>
5  * Copyright (c) 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * James A. Woods.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. 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  * $FreeBSD$
36  */
37 
38 #if 0
39 #ifndef lint
40 static char copyright[] =
41 "@(#) Copyright (c) 1989, 1993\n\
42 	The Regents of the University of California.  All rights reserved.\n";
43 #endif /* not lint */
44 
45 #ifndef lint
46 static char sccsid[] = "@(#)locate.bigram.c	8.1 (Berkeley) 6/6/93";
47 #endif /* not lint */
48 #endif
49 
50 /*
51  *  bigram < sorted_file_names | sort -nr |
52  *  	awk 'NR <= 128 { printf $2 }' > bigrams
53  *
54  * List bigrams for 'updatedb' script.
55  * Use 'code' to encode a file using this output.
56  */
57 
58 #include <capsicum_helpers.h>
59 #include <err.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include "locate.h"
63 
64 u_char buf1[LOCATE_PATH_MAX] = " ";
65 u_char buf2[LOCATE_PATH_MAX];
66 unsigned long bigram[UCHAR_MAX + 1][UCHAR_MAX + 1];
67 
68 int
69 main(void)
70 {
71 	u_char *cp;
72 	u_char *oldpath = buf1, *path = buf2;
73 	u_int i, j;
74 
75 	if (caph_limit_stdio() < 0 || caph_enter() < 0)
76 		err(1, "capsicum");
77 
78      	while (fgets(path, sizeof(buf2), stdin) != NULL) {
79 
80 		/*
81 		 * We don't need remove newline character '\n'.
82 		 * '\n' is less than ASCII_MIN and will be later
83 		 * ignored at output.
84 		 */
85 
86 
87 		/* skip longest common prefix */
88 		for (cp = path; *cp == *oldpath; cp++, oldpath++)
89 			if (*cp == '\0')
90 				break;
91 
92 		while (*cp != '\0' && *(cp + 1) != '\0') {
93 			bigram[(u_char)*cp][(u_char)*(cp + 1)]++;
94 			cp += 2;
95 		}
96 
97 		/* swap pointers */
98 		if (path == buf1) {
99 			path = buf2;
100 			oldpath = buf1;
101 		} else {
102 			path = buf1;
103 			oldpath = buf2;
104 		}
105    	}
106 	if (!feof(stdin) || ferror(stdin))
107 		err(1, "stdin");
108 
109 
110 	/* output, boundary check */
111 	for (i = ASCII_MIN; i <= ASCII_MAX; i++)
112 		for (j = ASCII_MIN; j <= ASCII_MAX; j++)
113 			if (bigram[i][j] != 0)
114 				printf("%lu %c%c\n", bigram[i][j], i, j);
115 
116 	exit(0);
117 }
118