diff options
Diffstat (limited to 'appl/cmd/lookman.b')
| -rw-r--r-- | appl/cmd/lookman.b | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/appl/cmd/lookman.b b/appl/cmd/lookman.b new file mode 100644 index 00000000..53557c8b --- /dev/null +++ b/appl/cmd/lookman.b @@ -0,0 +1,250 @@ +implement Lookman; +include "sys.m"; +include "bufio.m"; +include "draw.m"; + + +Lookman : module { + init : fn (ctxt : ref Draw->Context, argv : list of string); +}; + +sys : Sys; +bufio : Bufio; +Iobuf : import bufio; + +ctype := array [256] of { * => byte 0 }; + +MANINDEX : con "/man/index"; + +init(nil : ref Draw->Context, argv : list of string) +{ + sys = load Sys Sys->PATH; + bufio = load Bufio Bufio->PATH; + + if (bufio == nil) + raise "init:fail"; + + # setup our char conversion table + # map upper-case to lower-case + for (i := 'A'; i <= 'Z'; i++) + ctype[i] = byte ((i - 'A') + 'a'); + + # only allow the following chars + okchars := "abcdefghijklmnopqrstuvwxyz0123456789+.:½ "; + for (i = 0; i < len okchars; i++) { + ch := okchars[i]; + ctype[ch] = byte ch; + } + + stdout := bufio->fopen(sys->fildes(1), Sys->OWRITE); + + argv = tl argv; + paths := lookup(argv); + for (; paths != nil; paths = tl paths) + stdout.puts(sys->sprint("%s\n", hd paths)); + stdout.flush(); +} + +lookup(words : list of string) : list of string +{ + # open the index file + manindex := bufio->open(MANINDEX, Sys->OREAD); + if (manindex == nil) { + sys->print("cannot open %s: %r\n", MANINDEX); + return nil; + } + + # convert to lower-case and discard funny chars + keywords : list of string; + for (; words != nil; words = tl words) { + word := hd words; + kw := ""; + for (i := 0; i < len word; i++) { + ch := word[i]; + if (ch < len ctype && ctype[ch] != byte 0) + kw[len kw] = int ctype[ch]; + } + if (kw != "") + keywords = kw :: keywords; + } + + if (keywords == nil) + return nil; + + keywords = sortuniq(keywords); + matches : list of list of string; + + for (; keywords != nil; keywords = tl keywords) { + kw := hd keywords; + matchlist := look(manindex, '\t', kw); + pathlist : list of string = nil; + for (; matchlist != nil; matchlist = tl matchlist) { + line := hd matchlist; + (n, toks) := sys->tokenize(line, "\t"); + if (n != 2) + continue; + pathlist = hd tl toks :: pathlist; + } + if (pathlist != nil) + matches = pathlist :: matches; + } + + return intersect(matches); +} + +getentry(iob : ref Iobuf) : (string, string) +{ + while ((s := iob.gets('\n')) != nil) { + if (s[len s -1] == '\n') + s = s[0:len s -1]; + if (s == nil) + continue; + (n, toks) := sys->tokenize(s, "\t"); + if (n != 2) + continue; + return (hd toks, hd tl toks); + } + return (nil, nil); +} + +sortuniq(strlist : list of string) : list of string +{ + strs := array [len strlist] of string; + for (i := 0; strlist != nil; (i, strlist) = (i+1, tl strlist)) + strs[i] = hd strlist; + + # simple sort (greatest first) + for (i = 0; i < len strs - 1; i++) { + for (j := i+1; j < len strs; j++) + if (strs[i] < strs[j]) + (strs[i], strs[j]) = (strs[j], strs[i]); + } + + # construct list (result is ascending) + r : list of string; + prev := ""; + for (i = 0; i < len strs; i++) { + if (strs[i] != prev) { + r = strs[i] :: r; + prev = strs[i]; + } + } + return r; +} + +intersect(strlists : list of list of string) : list of string +{ + if (strlists == nil) + return nil; + + okl := hd strlists; + for (strlists = tl strlists; okl != nil && strlists != nil; strlists = tl strlists) { + find := hd strlists; + found : list of string = nil; + for (; okl != nil; okl = tl okl) { + ok := hd okl; + for (scanl := find; scanl != nil; scanl = tl scanl) { + scan := hd scanl; + if (scan == ok) { + found = ok :: found; + break; + } + } + } + okl = found; + } + return sortuniq(okl); +} + +# binary search for key in f. +# based on Plan 9 look.c +# +look(f: ref Iobuf, sep: int, key: string): list of string +{ + bot := mid := 0; + top := int f.seek(big 0, Sys->SEEKEND); + key = canon(key, sep); + + for (;;) { + mid = (top + bot) / 2; + f.seek(big mid, Sys->SEEKSTART); + c: int; + do { + c = f.getb(); + mid++; + } while (c != Bufio->EOF && c != Bufio->ERROR && c != '\n'); + (entry, eof) := getword(f); + if (entry == nil && eof) + break; + entry = canon(entry, sep); + case comparewords(key, entry) { + -2 or -1 or 0 => + if (top <= mid) + break; + top = mid; + continue; + 1 or 2 => + bot = mid; + continue; + } + break; + } + matchlist : list of string; + f.seek(big bot, Sys->SEEKSTART); + for (;;) { + (entry, eof) := getword(f); + if (entry == nil && eof) + return matchlist; + word := canon(entry, sep); + case comparewords(key, word) { + -1 or 0 => + matchlist = entry :: matchlist; + continue; + 1 or 2 => + continue; + } + break; + } + return matchlist; +} + +comparewords(s, t: string): int +{ + if (s == t) + return 0; + i := 0; + for (; i < len s && i < len t && s[i] == t[i]; i++) + ; + if (i >= len s) + return -1; + if (i >= len t) + return 1; + if (s[i] < t[i]) + return -2; + return 2; +} + +getword(f: ref Iobuf): (string, int) +{ + ret := ""; + for (;;) { + c := f.getc(); + if (c == Bufio->EOF || c == Bufio->ERROR) + return (ret, 0); + if (c == '\n') + break; + ret[len ret] = c; + } + return (ret, 1); +} + +canon(s: string, sep: int): string +{ + if (sep < 0) + return s; + i := 0; + for (; i < len s; i++) + if (s[i] == sep) + break; + return s[0:i]; +} |