add share.sh to demonstrate usage from the shell

share.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+# Share data to a running Shrlok instance.
+
+usage() {
+    echo "Usage: $0 [-s SOCKET_PATH] [] TYPE FILE"
+}
+
+socket_path="/run/shrlok/shr.sock"
+while getopts "hs:" OPTION; do
+    case $OPTION in
+        h) usage; exit 0 ;;
+        s) socket_path="$OPTARG" ;;
+        *) usage; exit 1 ;;
+    esac
+done
+shift $(( OPTIND - 1 ))
+[ $# != 2 ] && usage && exit 1
+
+share_type="$1"
+input_file="$2"
+
+if [ ! -S "$socket_path" ]; then
+    echo "$socket_path is not a valid Unix socket. Is shrlok running?"
+    exit 1
+fi
+
+# The first thing sent through the socket is the total packet length, as ASCII
+# digits for the convenience of scripts. Build the header before hand to get its
+# size, then get the file length and push everything to the socket with socat.
+header="{\"type\":\"$share_type\"}"
+header_length="${#header}"
+file_length="$(wc -c "$input_file" | cut -d' ' -f1)"
+full_length="$(( $header_length + 1 + $file_length ))"
+
+cat <(printf "${full_length}\x00${header}\x00") "$input_file" \
+    | socat - UNIX-CONNECT:"$socket_path" ; echo