@ISA = qw(Exporter);
@EXPORT = qw(look);
-# Usage: look(*FILEHANDLE,$key,$dict,$fold)
+=head1 NAME
-# Sets file position in FILEHANDLE to be first line greater than or equal
-# (stringwise) to $key. Pass flags for dictionary order and case folding.
+Search::Dict, look - search for key in dictionary file
+
+=head1 SYNOPSIS
+
+ use Search::Dict;
+ look *FILEHANDLE, $key, $dict, $fold;
+
+=head1 DESCRIPTION
+
+Sets file position in FILEHANDLE to be first line greater than or equal
+(stringwise) to I<$key>. Returns the new file position, or -1 if an error
+occurs.
+
+The flags specify dictionary order and case folding:
+
+If I<$dict> is true, search by dictionary order (ignore anything but word
+characters and whitespace).
+
+If I<$fold> is true, ignore case.
+
+=cut
sub look {
local(*FH,$key,$dict,$fold) = @_;
- local($max,$min,$mid,$_);
- local($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,
- $blksize,$blocks) = stat(FH);
- $blksize = 8192 unless $blksize;
+ local($_);
+ my(@stat) = stat(FH)
+ or return -1;
+ my($size, $blksize) = @stat[7,11];
+ $blksize ||= 8192;
$key =~ s/[^\w\s]//g if $dict;
- $key =~ tr/A-Z/a-z/ if $fold;
- $max = int($size / $blksize);
+ $key = lc $key if $fold;
+ my($min, $max, $mid) = (0, int($size / $blksize));
while ($max - $min > 1) {
$mid = int(($max + $min) / 2);
- seek(FH,$mid * $blksize,0);
- $_ = <FH> if $mid; # probably a partial line
+ seek(FH, $mid * $blksize, 0)
+ or return -1;
+ <FH> if $mid; # probably a partial line
$_ = <FH>;
chop;
s/[^\w\s]//g if $dict;
- tr/A-Z/a-z/ if $fold;
- if ($_ lt $key) {
+ $_ = lc $_ if $fold;
+ if (defined($_) && $_ lt $key) {
$min = $mid;
}
else {
}
}
$min *= $blksize;
- seek(FH,$min,0);
+ seek(FH,$min,0)
+ or return -1;
<FH> if $min;
- while (<FH>) {
+ for (;;) {
+ $min = tell(FH);
+ defined($_ = <FH>)
+ or last;
chop;
s/[^\w\s]//g if $dict;
- y/A-Z/a-z/ if $fold;
+ $_ = lc $_ if $fold;
last if $_ ge $key;
- $min = tell(FH);
}
seek(FH,$min,0);
$min;
}
1;
-