Handle files with leading at signs, update README

Author: dankamongmen

README.md

@@ -167,13 +167,6 @@ GitHub.
   will be removed once xterm can handle images greater than 1000x1000.
   [Last tested with XTerm(344)].
 
-* Filenames that begin with "@" are special to ImageMagick and it'll
-  freak out if you don't prepend a directory. (`lsix ./@foo.png`)
-  (This is a bug in ImageMagick, not lsix).
-
-* Specifying the empty string `""` as a filename makes ImageMagick hang.
-  (This appears to be an ImageMagick bug / misfeature). 
-
 * Long filenames are wrapped, but not intelligently. Would it
   complicate this script too much to make it prefer to wrap on whites
   space, dashes, underscores, and periods? Maybe.
@@ -274,4 +267,4 @@ GitHub.
 
   * [VT340 Test](https://github.com/hackerb9/vt340test), a project to document the actual behaviour of the DEC VT340 hardware.
 
-  * [Digital ANSI-Compliant Printing Protocol: Level 2 Programming Reference Manual](http://www.vaxhaven.com/images/f/f7/EK-PPLV2-PM-B01.pdf), Chapter 5: Sixel Graphics. An excellent and reasonably clear discussion for anyone who wants to generate or parse sixel graphics.
+  * [Digital ANSI-Compliant Printing Protocol: Level 2 Programming Reference Manual](http://www.vaxhaven.com/images/f/f7/EK-PPLV2-PM-B01.pdf), Chapter 5: Sixel Graphics. An excellent and reasonably clear discussion for anyone who wants to generate or parse sixel graphics.

lsix

@@ -234,14 +234,19 @@ main() {
 	    len=${#onerow[@]}
 	    onerow[len++]="-label"
 	    onerow[len++]=$(processlabel "$1")
-	    onerow[len++]="file://$1"
+      onerow[len++]="file://$(imescape $1)"
 	    shift
 	done
-	montage "${onerow[@]}"  $imoptions gif:-  \
+
+  montage "${onerow[@]}"  $imoptions gif:-  \
 	    | convert - -colors $numcolors sixel:-
     done
 }
 
+imescape() {
+    echo "$@" | sed -e 's|^@|./@|g;'
+}
+
 processlabel() {
     # This routine is all about appeasing ImageMagick.
     # 1. Remove silly [0] suffix and : prefix.