xref: /freebsd/usr.bin/locate/bigram/locate.bigram.c (revision fed1ca4b719c56c930f2259d80663cd34be812bb)
1 /*
2  * Copyright (c) 1995 Wolfram Schneider <wosch@FreeBSD.org>. Berlin.
3  * Copyright (c) 1989, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * This code is derived from software contributed to Berkeley by
7  * James A. Woods.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by the University of
20  *	California, Berkeley and its contributors.
21  * 4. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  * $FreeBSD$
38  */
39 
40 #if 0
41 #ifndef lint
42 static char copyright[] =
43 "@(#) Copyright (c) 1989, 1993\n\
44 	The Regents of the University of California.  All rights reserved.\n";
45 #endif /* not lint */
46 
47 #ifndef lint
48 static char sccsid[] = "@(#)locate.bigram.c	8.1 (Berkeley) 6/6/93";
49 #endif /* not lint */
50 #endif
51 
52 /*
53  *  bigram < sorted_file_names | sort -nr |
54  *  	awk 'NR <= 128 { printf $2 }' > bigrams
55  *
56  * List bigrams for 'updatedb' script.
57  * Use 'code' to encode a file using this output.
58  */
59 
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <sys/param.h>			/* for MAXPATHLEN */
63 #include "locate.h"
64 
65 u_char buf1[MAXPATHLEN] = " ";
66 u_char buf2[MAXPATHLEN];
67 u_int bigram[UCHAR_MAX + 1][UCHAR_MAX + 1];
68 
69 int
70 main(void)
71 {
72 	u_char *cp;
73 	u_char *oldpath = buf1, *path = buf2;
74 	u_int i, j;
75 
76      	while (fgets(path, sizeof(buf2), stdin) != NULL) {
77 
78 		/*
79 		 * We don't need remove newline character '\n'.
80 		 * '\n' is less than ASCII_MIN and will be later
81 		 * ignored at output.
82 		 */
83 
84 
85 		/* skip longest common prefix */
86 		for (cp = path; *cp == *oldpath; cp++, oldpath++)
87 			if (*cp == '\0')
88 				break;
89 
90 		while (*cp != '\0' && *(cp + 1) != '\0') {
91 			bigram[(u_char)*cp][(u_char)*(cp + 1)]++;
92 			cp += 2;
93 		}
94 
95 		/* swap pointers */
96 		if (path == buf1) {
97 			path = buf2;
98 			oldpath = buf1;
99 		} else {
100 			path = buf1;
101 			oldpath = buf2;
102 		}
103    	}
104 
105 	/* output, boundary check */
106 	for (i = ASCII_MIN; i <= ASCII_MAX; i++)
107 		for (j = ASCII_MIN; j <= ASCII_MAX; j++)
108 			if (bigram[i][j] != 0)
109 				(void)printf("%4u %c%c\n", bigram[i][j], i, j);
110 
111 	exit(0);
112 }
113