tweaks

1 files changed, 342 insertions, 0 deletions

diff --git a/src/cmd/look.c b/src/cmd/look.c
new file mode 100644
index 00000000..5b300868
--- /dev/null
+++ b/src/cmd/look.c
@@ -0,0 +1,342 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+	/* Macros for Rune support of ctype.h-like functions */
+
+#define	isupper(r)	(L'A' <= (r) && (r) <= L'Z')
+#define	islower(r)	(L'a' <= (r) && (r) <= L'z')
+#define	isalpha(r)	(isupper(r) || islower(r))
+#define	islatin1(r)	(0xC0 <= (r) && (r) <= 0xFF)
+
+#define	isdigit(r)	(L'0' <= (r) && (r) <= L'9')
+
+#define	isalnum(r)	(isalpha(r) || isdigit(r))
+
+#define	isspace(r)	((r) == L' ' || (r) == L'\t' \
+			|| (0x0A <= (r) && (r) <= 0x0D))
+
+#define	tolower(r)	((r)-'A'+'a')
+
+#define	sgn(v)		((v) < 0 ? -1 : ((v) > 0 ? 1 : 0))
+
+#define	WORDSIZ	4000
+char	*filename = "#9/lib/words";
+Biobuf	*dfile;
+Biobuf	bout;
+Biobuf	bin;
+
+int	fold;
+int	direc;
+int	exact;
+int	iflag;
+int	rev = 1;	/*-1 for reverse-ordered file, not implemented*/
+int	(*compare)(Rune*, Rune*);
+Rune	tab = '\t';
+Rune	entry[WORDSIZ];
+Rune	word[WORDSIZ];
+Rune	key[50], orig[50];
+Rune	latin_fold_tab[] =
+{
+/*	Table to fold latin 1 characters to ASCII equivalents
+			based at Rune value 0xc0
+
+	 À    Á    Â    Ã    Ä    Å    Æ    Ç
+	 È    É    Ê    Ë    Ì    Í    Î    Ï
+	 Ð    Ñ    Ò    Ó    Ô    Õ    Ö    ×
+	 Ø    Ù    Ú    Û    Ü    Ý    Þ    ß
+	 à    á    â    ã    ä    å    æ    ç
+	 è    é    ê    ë    ì    í    î    ï
+	 ð    ñ    ò    ó    ô    õ    ö    ÷
+	 ø    ù    ú    û    ü    ý    þ    ÿ
+*/
+	'a', 'a', 'a', 'a', 'a', 'a', 'a', 'c',
+	'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',
+	'd', 'n', 'o', 'o', 'o', 'o', 'o',  0 ,
+	'o', 'u', 'u', 'u', 'u', 'y',  0 ,  0 ,
+	'a', 'a', 'a', 'a', 'a', 'a', 'a', 'c',
+	'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i',
+	'd', 'n', 'o', 'o', 'o', 'o', 'o',  0 ,
+	'o', 'u', 'u', 'u', 'u', 'y',  0 , 'y',
+};
+
+int	locate(void);
+int	acomp(Rune*, Rune*);
+int	getword(Biobuf*, Rune *rp, int n);
+void	torune(char*, Rune*);
+void	rcanon(Rune*, Rune*);
+int	ncomp(Rune*, Rune*);
+
+void
+main(int argc, char *argv[])
+{
+	int n;
+
+	filename = unsharp(filename);
+
+	Binit(&bin, 0, OREAD);
+	Binit(&bout, 1, OWRITE);
+	compare = acomp;
+	ARGBEGIN{
+	case 'd':
+		direc++;
+		break;
+	case 'f':
+		fold++;
+		break;
+	case 'i': 
+		iflag++;
+		break;
+	case 'n':
+		compare = ncomp;
+		break;
+	case 't':
+		chartorune(&tab,ARGF());
+		break;
+	case 'x':
+		exact++;
+		break;
+	default:
+		fprint(2, "%s: bad option %c\n", argv0, ARGC());
+		fprint(2, "usage: %s -[dfinx] [-t c] [string] [file]\n", argv0);
+		exits("usage");
+	} ARGEND
+	if(!iflag){
+		if(argc >= 1) {
+			torune(argv[0], orig);
+			argv++;
+			argc--;
+		} else
+			iflag++;
+	}
+	if(argc < 1) {
+		direc++;
+		fold++;
+	} else 
+		filename = argv[0];
+	if (!iflag)
+		rcanon(orig, key);
+	dfile = Bopen(filename, OREAD);
+	if(dfile == 0) {
+		fprint(2, "look: can't open %s\n", filename);
+		exits("no dictionary");
+	}
+	if(!iflag)
+		if(!locate())
+			exits("not found");
+	do {
+		if(iflag) {
+			Bflush(&bout);
+			if(!getword(&bin, orig, sizeof(orig)/sizeof(orig[0])))
+				exits(0);
+			rcanon(orig, key);
+			if(!locate())
+				continue;
+		}
+		if (!exact || !acomp(word, key))
+			Bprint(&bout, "%S\n", entry);
+		while(getword(dfile, entry, sizeof(entry)/sizeof(entry[0]))) {
+			rcanon(entry, word);
+			n = compare(key, word);
+			switch(n) {
+			case -1:
+				if(exact)
+					break;
+			case 0:
+				if (!exact || !acomp(word, orig))
+					Bprint(&bout, "%S\n", entry);
+				continue;
+			}
+			break;
+		}
+	} while(iflag);
+	exits(0);
+}
+
+int
+locate(void)
+{
+	long top, bot, mid;
+	long c;
+	int n;
+
+	bot = 0;
+	top = Bseek(dfile, 0L, 2);
+	for(;;) {
+		mid = (top+bot) / 2;
+		Bseek(dfile, mid, 0);
+		do
+			c = Bgetrune(dfile);
+		while(c>=0 && c!='\n');
+		mid = Boffset(dfile);
+		if(!getword(dfile, entry, sizeof(entry)/sizeof(entry[0])))
+			break;
+		rcanon(entry, word);
+		n = compare(key, word);
+		switch(n) {
+		case -2:
+		case -1:
+		case 0:
+			if(top <= mid)
+				break;
+			top = mid;
+			continue;
+		case 1:
+		case 2:
+			bot = mid;
+			continue;
+		}
+		break;
+	}
+	Bseek(dfile, bot, 0);
+	while(getword(dfile, entry, sizeof(entry)/sizeof(entry[0]))) {
+		rcanon(entry, word);
+		n = compare(key, word);
+		switch(n) {
+		case -2:
+			return 0;
+		case -1:
+			if(exact)
+				return 0;
+		case 0:
+			return 1;
+		case 1:
+		case 2:
+			continue;
+		}
+	}
+	return 0;
+}
+
+/*
+ *	acomp(s, t) returns:
+ *		-2 if s strictly precedes t
+ *		-1 if s is a prefix of t
+ *		0 if s is the same as t
+ *		1 if t is a prefix of s
+ *		2 if t strictly precedes s
+ */
+
+int
+acomp(Rune *s, Rune *t)
+{
+	int cs, ct;
+
+	for(;;) {
+		cs = *s;
+		ct = *t;
+		if(cs != ct)
+			break;
+		if(cs == 0)
+			return 0;
+		s++;
+		t++;
+	}
+	if(cs == 0)
+		return -1;
+	if(ct == 0)
+		return 1;
+	if(cs < ct)
+		return -2;
+	return 2;
+}
+
+void
+torune(char *old, Rune *new)
+{
+	do old += chartorune(new, old);
+	while(*new++);
+}
+
+void
+rcanon(Rune *old, Rune *new)
+{
+	Rune r;
+
+	while((r = *old++) && r != tab) {
+		if (islatin1(r) && latin_fold_tab[r-0xc0])
+				r = latin_fold_tab[r-0xc0];
+		if(direc)
+			if(!(isalnum(r) || r == L' ' || r == L'\t'))
+				continue;
+		if(fold)
+			if(isupper(r))
+				r = tolower(r);
+		*new++ = r;
+	}
+	*new = 0;
+}
+
+int
+ncomp(Rune *s, Rune *t)
+{
+	Rune *is, *it, *js, *jt;
+	int a, b;
+	int ssgn, tsgn;
+
+	while(isspace(*s))
+		s++;
+	while(isspace(*t))
+		t++;
+	ssgn = tsgn = -2*rev;
+	if(*s == '-') {
+		s++;
+		ssgn = -ssgn;
+	}
+	if(*t == '-') {
+		t++;
+		tsgn = -tsgn;
+	}
+	for(is = s; isdigit(*is); is++)
+		;
+	for(it = t; isdigit(*it); it++)
+		;
+	js = is;
+	jt = it;
+	a = 0;
+	if(ssgn == tsgn)
+		while(it>t && is>s)
+			if(b = *--it - *--is)
+				a = b;
+	while(is > s)
+		if(*--is != '0')
+			return -ssgn;
+	while(it > t)
+		if(*--it != '0')
+			return tsgn;
+	if(a)
+		return sgn(a)*ssgn;
+	if(*(s=js) == '.')
+		s++;
+	if(*(t=jt) == '.')
+		t++;
+	if(ssgn == tsgn)
+		while(isdigit(*s) && isdigit(*t))
+			if(a = *t++ - *s++)
+				return sgn(a)*ssgn;
+	while(isdigit(*s))
+		if(*s++ != '0')
+			return -ssgn;
+	while(isdigit(*t))
+		if(*t++ != '0')
+			return tsgn;
+	return 0;
+}
+
+int
+getword(Biobuf *f, Rune *rp, int n)
+{
+	long c;
+
+	while(n-- > 0) {
+		c = Bgetrune(f);
+		if(c < 0)
+			return 0;
+		if(c == '\n') {
+			*rp = L'\0';
+			return 1;
+		}
+		*rp++ = c;
+	}
+	fprint(2, "Look: word too long.  Bailing out.\n");
+	return 0;
+}