[unix-history] / usr / src / cmd / look.c

#include <stdio.h>
#include <ctype.h>

FILE *dfile;
char *filenam  = "/usr/dict/words";

int fold;
int dict;
int tab;
char entry[250];
char word[250];
char key[50];

main(argc,argv)
char **argv;
{
	register c;
	long top,bot,mid;
	while(argc>=2 && *argv[1]=='-') {
		for(;;) {
			switch(*++argv[1]) {
			case 'd':
				dict++;
				continue;
			case 'f':
				fold++;
				continue;
			case 't':
				tab = argv[1][1];
				if(tab)
					++argv[1];
				continue;
			case 0:
				break;
			default:
				continue;
			}
			break;
		}
		argc --;
		argv++;
	}
	if(argc<=1)
		return;
	if(argc==2) {
		fold++;
		dict++;
	} else
		filenam = argv[2];
	dfile = fopen(filenam,"r");
	if(dfile==NULL) {
		fprintf(stderr,"look: can't open %s\n",filenam);
		exit(2);
	}
	canon(argv[1],key);
	bot = 0;
	fseek(dfile,0L,2);
	top = ftell(dfile);
	for(;;) {
		mid = (top+bot)/2;
		fseek(dfile,mid,0);
		do {
			c = getc(dfile);
			mid++;
		} while(c!=EOF && c!='\n');
		if(!getword(entry))
			break;
		canon(entry,word);
		switch(compare(key,word)) {
		case -2:
		case -1:
		case 0:
			if(top<=mid)
				break;
			top = mid;
			continue;
		case 1:
		case 2:
			bot = mid;
			continue;
		}
		break;
	}
	fseek(dfile,bot,0);
	while(ftell(dfile)<top) {
		if(!getword(entry))
			return;
		canon(entry,word);
		switch(compare(key,word)) {
		case -2:
			return;
		case -1:
		case 0:
			puts(entry,stdout);
			break;
		case 1:
		case 2:
			continue;
		}
		break;
	}
	while(getword(entry)) {
		canon(entry,word);
		switch(compare(key,word)) {
		case -1:
		case 0:
			puts(entry,stdout);
			continue;
		}
		break;
	}
}

compare(s,t)
register char *s,*t;
{
	for(;*s==*t;s++,t++)
		if(*s==0)
			return(0);
	return(*s==0? -1:
		*t==0? 1:
		*s<*t? -2:
		2);
}

getword(w)
char *w;
{
	register c;
	for(;;) {
		c = getc(dfile);
		if(c==EOF)
			return(0);
		if(c=='\n')
			break;
		*w++ = c;
	}
	*w = 0;
	return(1);
}

canon(old,new)
char *old,*new;
{
	register c;
	for(;;) {
		*new = c = *old++;
		if(c==0||c==tab) {
			*new = 0;
			break;
		}
		if(dict) {
			if(!isalnum(c))
				continue;
		}
		if(fold) {
			if(isupper(c))
				*new += 'a' - 'A';
		}
		new++;
	}
}
Commit	Line	Data
9c79dca0 BJ	1	#include <stdio.h>
	2	#include <ctype.h>
	3
	4	FILE *dfile;
	5	char *filenam = "/usr/dict/words";
	6
	7	int fold;
	8	int dict;
	9	int tab;
	10	char entry[250];
	11	char word[250];
	12	char key[50];
	13
	14	main(argc,argv)
	15	char **argv;
	16	{
	17	register c;
	18	long top,bot,mid;
	19	while(argc>=2 && *argv[1]=='-') {
	20	for(;;) {
	21	switch(*++argv[1]) {
	22	case 'd':
	23	dict++;
	24	continue;
	25	case 'f':
	26	fold++;
	27	continue;
	28	case 't':
	29	tab = argv[1][1];
	30	if(tab)
	31	++argv[1];
	32	continue;
	33	case 0:
	34	break;
	35	default:
	36	continue;
	37	}
	38	break;
	39	}
	40	argc --;
	41	argv++;
	42	}
	43	if(argc<=1)
	44	return;
	45	if(argc==2) {
	46	fold++;
	47	dict++;
	48	} else
	49	filenam = argv[2];
	50	dfile = fopen(filenam,"r");
	51	if(dfile==NULL) {
	52	fprintf(stderr,"look: can't open %s\n",filenam);
	53	exit(2);
	54	}
	55	canon(argv[1],key);
	56	bot = 0;
	57	fseek(dfile,0L,2);
	58	top = ftell(dfile);
	59	for(;;) {
	60	mid = (top+bot)/2;
	61	fseek(dfile,mid,0);
	62	do {
	63	c = getc(dfile);
	64	mid++;
65	} while(c!=EOF && c!='\n');
66	if(!getword(entry))
67	break;
68	canon(entry,word);
69	switch(compare(key,word)) {
70	case -2:
71	case -1:
72	case 0:
73	if(top<=mid)
74	break;
75	top = mid;
76	continue;
77	case 1:
78	case 2:
79	bot = mid;
80	continue;
81	}
82	break;
83	}
84	fseek(dfile,bot,0);
85	while(ftell(dfile)<top) {
86	if(!getword(entry))
87	return;
88	canon(entry,word);
89	switch(compare(key,word)) {
90	case -2:
91	return;
92	case -1:
93	case 0:
94	puts(entry,stdout);
95	break;
96	case 1:
97	case 2:
98	continue;
99	}
100	break;
101	}
102	while(getword(entry)) {
103	canon(entry,word);
104	switch(compare(key,word)) {
105	case -1:
106	case 0:
107	puts(entry,stdout);
108	continue;
109	}
110	break;
111	}
112	}
113
114	compare(s,t)
115	register char s,t;
116	{
117	for(;s==t;s++,t++)
118	if(*s==0)
119	return(0);
120	return(*s==0? -1:
121	*t==0? 1:
122	s<t? -2:
123	2);
124	}
125
126	getword(w)
127	char *w;
128	{
129	register c;
130	for(;;) {
131	c = getc(dfile);
132	if(c==EOF)
133	return(0);
134	if(c=='\n')
135	break;
136	*w++ = c;
137	}
138	*w = 0;
139	return(1);
140	}
141
142	canon(old,new)
143	char old,new;
144	{
145	register c;
146	for(;;) {
147	new = c = old++;
148	if(c==0\|\|c==tab) {
149	*new = 0;
150	break;
151	}
152	if(dict) {
153	if(!isalnum(c))
154	continue;
155	}
156	if(fold) {
157	if(isupper(c))
158	*new += 'a' - 'A';
159	}
160	new++;
161	}
162	}