add image viewer script

scripts/examples/spmenu_imageviewer.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+[ ! -f "$1" ] && printf "You must specify an image to view.\n" && exit 1
+
+genlist() {
+    argc="$(printf "%s\n" "$@" | wc -l)"
+
+    for i in $(seq "$argc"); do
+        arg="$(printf "%s\n" "$@" | sed -n "${i}","${i}"p)"
+        [ -z "$arg" ] || [ ! -f "$arg" ] && continue
+        printf "IMG:%s\t%s\n" "$arg" "$arg"
+    done
+}
+
+main() {
+    genlist "$@" | spmenu --hide-mode --hide-match-count --hide-left-arrow --hide-right-arrow --hide-prompt --hide-cursor --hide-highlighting --image-size 200 --generate-cache
+}
+
+main "$@"