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-rwxr-xr-xMaster/tlpkg/tlperl0/lib/look.pl50
1 files changed, 50 insertions, 0 deletions
diff --git a/Master/tlpkg/tlperl0/lib/look.pl b/Master/tlpkg/tlperl0/lib/look.pl
new file mode 100755
index 00000000000..ccc9b6162ae
--- /dev/null
+++ b/Master/tlpkg/tlperl0/lib/look.pl
@@ -0,0 +1,50 @@
+;# Usage: &look(*FILEHANDLE,$key,$dict,$fold)
+#
+# This library is no longer being maintained, and is included for backward
+# compatibility with Perl 4 programs which may require it.
+#
+# In particular, this should not be used as an example of modern Perl
+# programming techniques.
+#
+;# Sets file position in FILEHANDLE to be first line greater than or equal
+;# (stringwise) to $key. Pass flags for dictionary order and case folding.
+
+sub look {
+ local(*FH,$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;
+ $key =~ s/[^\w\s]//g if $dict;
+ $key = lc $key if $fold;
+ $max = int($size / $blksize);
+ while ($max - $min > 1) {
+ $mid = int(($max + $min) / 2);
+ seek(FH,$mid * $blksize,0);
+ $_ = <FH> if $mid; # probably a partial line
+ $_ = <FH>;
+ chop;
+ s/[^\w\s]//g if $dict;
+ $_ = lc $_ if $fold;
+ if ($_ lt $key) {
+ $min = $mid;
+ }
+ else {
+ $max = $mid;
+ }
+ }
+ $min *= $blksize;
+ seek(FH,$min,0);
+ <FH> if $min;
+ while (<FH>) {
+ chop;
+ s/[^\w\s]//g if $dict;
+ $_ = lc $_ if $fold;
+ last if $_ ge $key;
+ $min = tell(FH);
+ }
+ seek(FH,$min,0);
+ $min;
+}
+
+1;