xref: /freebsd/usr.bin/locate/bigram/locate.bigram.c (revision a0e7cb0fadf19c175b99a188e639a3d175ba674b)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * James A. Woods.
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. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * 	$Id: locate.bigram.c,v 1.4 1996/08/22 18:46:11 wosch Exp $
37  */
38 
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 
49 /*
50  *  bigram < sorted_file_names | sort -nr |
51  *  	awk 'NR <= 128 { printf $2 }' > bigrams
52  *
53  * List bigrams for 'updatedb' script.
54  * Use 'code' to encode a file using this output.
55  */
56 
57 #include <stdio.h>
58 #include <sys/param.h>			/* for MAXPATHLEN */
59 #include "locate.h"
60 
61 u_char buf1[MAXPATHLEN] = " ";
62 u_char buf2[MAXPATHLEN];
63 u_int bigram[UCHAR_MAX][UCHAR_MAX];
64 
65 int
66 main(void)
67 {
68   	register u_char *cp;
69 	register u_char *oldpath = buf1, *path = buf2;
70 	register u_int i, j;
71 
72      	while (fgets(path, sizeof(buf2), stdin) != NULL) {
73 
74 	    	/* skip empty lines */
75 		if (*path == '\n')
76 			continue;
77 
78 		/* Squelch characters that would botch the decoding. */
79 		for (cp = path; *cp != NULL; cp++) {
80 			/* chop newline */
81 			if (*cp == '\n')
82 				*cp = NULL;
83 			/* range */
84 			else if (*cp < ASCII_MIN || *cp > ASCII_MAX)
85 				*cp = '?';
86 		}
87 
88 		/* skip longest common prefix */
89 		for (cp = path; *cp == *oldpath && *cp != NULL; cp++, oldpath++);
90 
91 		while (*cp != NULL && *(cp+1) != NULL) {
92 			bigram[*cp][*(cp+1)]++;
93 			cp += 2;
94 		}
95 
96 		/* swap pointers */
97 		if (path == buf1) {
98 			path = buf2;
99 			oldpath = buf1;
100 		} else {
101 			path = buf1;
102 			oldpath = buf2;
103 		}
104    	}
105 
106 	/* output, (paranoid) boundary check */
107 	for (i = ASCII_MIN; i <= ASCII_MAX; i++)
108 		for (j = ASCII_MIN; j <= ASCII_MAX; j++)
109 			if (bigram[i][j] != 0)
110 				printf("%4u %c%c\n", bigram[i][j], i, j);
111 
112 	exit(0);
113 }
114