initial commit of the reg tool (listing part)

docker/builder/reg

+#!/bin/bash
+
+prod_tag="prod-running"
+
+declare -A digests
+i=0
+while read tag; do
+    digest="`regctl image digest "$1:$tag"`"
+    if [ -z "$digest" ]; then
+        digest="standalone-$tag"
+    fi
+    sp=" "
+    if [ -z "${digests[$digest]}" ]; then
+        sp="$i "
+        ((i++))
+    fi
+    digests["$digest"]="${digests[$digest]}$sp$tag"
+done < <(regctl tag list "$1" | semversort -r -L)
+
+for val in "${digests[@]}"; do
+    echo "$val"
+done | sort -n -t" " | sed 's/^[0-9]\+ //' | while read line; do
+    line_out=""
+    running_out=""
+    prod=""
+    for tag in $line; do
+        if [ "$tag" = "$prod_tag" ]; then
+            prod=1
+        else
+            sp=""
+            if [ -n "$line_out" ]; then
+                sp=" "
+            fi
+            line_out="$line_out$sp$tag"
+        fi
+
+    done
+
+    if [ -z "$line_out" ]; then
+        line_out="?"
+    fi
+
+    if [ -t 1 -a -n "$prod" ]; then
+        echo -ne '\033[0;32m'
+        echo -n "$line_out"
+        echo -ne '\033[0m'
+    else
+        echo -n "$line_out"
+    fi
+
+
+    if [ -n "$prod" ]; then
+        if [ -t 1 ]; then
+            echo -e ' [\033[0;31mR\033[0m]'
+        else
+            echo ' [R]'
+        fi
+    else
+        echo
+    fi
+done
+
+
+#for digest in "${!digests[@]}"; do
+#    echo "$digest ${digests[$digest]}"
+#done