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is /. superfluous? why not just say / ?
Post 302079191 by thestevew on Friday 7th of July 2006 10:13:13 AM
07-07-2006
Quote:
Originally Posted by james hanley
you say in many contexts they're the same. But is there any case you can name where /. is not the same as / ? e.g. one works and the other doesn't?
$ ls -ld /mnt
drwxr-xr-x 2 bin bin 512 16 Apr 2003 /mnt
listing /.mnt looks for a file called .mnt in /
$ ls -ld /.mnt
ls: 0653-341 The file /.mnt does not exist.
Interestingly
$ ls -ld /./mnt
drwxr-xr-x 2 bin bin 512 16 Apr 2003 /./mnt
and even (ad infinitum...)
$ ls -ld /./././././mnt
drwxr-xr-x 2 bin bin 512 16 Apr 2003 /./././././mnt !!
Quote:
Originally Posted by james hanley
note-
But regarding your use of the term 'current directory'
dot is a pointer to some directory not necessarily the current one. If you're in /home/blob/ and you do ls /. then the current directory is still /home/blob/
(pwd displays current directory, so that defines current directory) The / directory is just the one that ls is called on. I don't know of another term for the directory passed as an argument/parameter to a command. It's not (necessarily) the current/working directory. It could be any directory.
But regarding your use of the term 'current directory'
dot is a pointer to some directory not necessarily the current one. If you're in /home/blob/ and you do ls /. then the current directory is still /home/blob/
(pwd displays current directory, so that defines current directory) The / directory is just the one that ls is called on. I don't know of another term for the directory passed as an argument/parameter to a command. It's not (necessarily) the current/working directory. It could be any directory.
Tired now - can I have a lie down till my head stops hurting
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LEARN ABOUT DEBIAN
math::polygon::clip
Math::Polygon::Clip(3pm) User Contributed Perl Documentation Math::Polygon::Clip(3pm) NAME
Math::Polygon::Clip - frame a polygon in a square INHERITANCE
Math::Polygon::Clip is a Exporter SYNOPSIS
my @poly = ( [1,2], [2,4], [5,7], [1, 2] ); my @box = ( $xmin, $ymin, $xmax, $ymax ); my $boxed = polygon_clip @box, @poly; DESCRIPTION
Cut-off all parts of the polygon which are outside the box FUNCTIONS
polygon_fill_clip1(ARRAY-BOX, LIST-OF-POINTS) Clipping a polygon into rectangles can be done in various ways. With this algorithm (which I designed myself, but may not be new), the parts of the polygon which are outside the BOX are mapped on the borders. The polygon stays in one piece. Returned is one list of points, which is cleaned from double points, spikes and superfluous intermediate points. polygon_fill_clip2(ARRAY-BOX, LIST-OF-POINTS) To be implemented. The polygon falls apart in fragments, which are not connected: paths which are followed in two directions are removed. This is required by some applications, like polygons used in geographical context (country contours and such). polygon_fill_clip3(ARRAY-BOX, OUT-POLY, [IN-POLYS]) To be implemented. A surrounding polygon, with possible inclussions. polygon_line_clip(ARRAY-BOX, LIST-OF-POINTS) Returned is a list of ARRAYS (possibly 0 long) containing line pieces from the input polygon (or line). example: my @points = ( [1,2], [2,3], [2,0], [1,-1], [1,2] ); my @bbox = ( 0, -2, 2, 2 ); my @l = polygon_line_clip @bbox, @points; print scalar @l; # 1, only one piece found my @first = @{$l[0]}; # first is [2,0], [1,-1], [1,2] SEE ALSO
This module is part of Math-Polygon distribution version 1.02, built on September 19, 2011. Website: http://perl.overmeer.net/geo/ LICENSE
Copyrights 2004,2006-2011 by Mark Overmeer. For other contributors see ChangeLog. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See http://www.perl.com/perl/misc/Artistic.html perl v5.12.4 2011-09-19 Math::Polygon::Clip(3pm)