ref: 5743b4623e800b8089c254c7997988344ddef2a2
dir: /sys/src/cmd/look.c/
#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 = "/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
usage(void)
{
fprint(2, "usage: %s [-dfinx] [-t c] [string] [file]\n", argv0);
exits("usage");
}
void
main(int argc, char *argv[])
{
int n;
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, EARGF(usage()));
break;
case 'x':
exact++;
break;
default:
fprint(2, "%s: bad option %c\n", argv0, ARGC());
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)
{
vlong top, bot, mid;
long c;
int n;
bot = 0;
top = Bseek(dfile, 0, 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;
}