Added script for extracting checksums

scripts/extract-checksum.sh

@@ -0,0 +1,51 @@
+#!/bin/bash
+
+# This script works with checksums_hashes_order and checksums to extract the relevant
+# sha of the various yq downloads. You can then use your favourite checksum tool to validate.
+# <CHECKSUM> must match an entry in checksums_hashes_order.
+#
+# Usage: ./extract-checksum.sh <CHECKSUM> <FILE>
+# E.g: ./extract-checksum.sh SHA-256 yq_linux_amd64.tar
+# Outputs: 
+# yq_linux_amd64.tar.gz	acebc9d07aa2d0e482969b2c080ee306e8f58efbd6f2d857eefbce6469da1473
+#
+# Usage with rhash:
+# ./extract-checksum.sh SHA-256 yq_linux_amd64.tar | rhash -c -
+#
+# Tip, if you want the checksum first then the filename  (e.g. for the md5sum command)
+# then you can pipe the output of this script into awk to switch the fields around:
+#
+# ./extract-checksum.sh MD5 yq_linux_amd64.tar | awk '{ print $2 " " $1}' | md5sum -c -
+#
+#
+
+if [ "$1" == "" ]; then
+  echo "Please specify at a hash algorithm from the checksum_hashes_order"
+  echo "Usage: $0 <HASH-ALG> <FILE>"
+  exit 1
+fi
+
+if [ -z "checksums_hashes_order" ]; then
+  echo "This script requires checksums_hashes_order to run"
+  exit 1
+fi
+
+if [ -z "checksums" ]; then
+  echo "This script requires checksums to run"
+  exit 1
+fi
+
+
+grepMatch=$(grep -m 1 -n "$1" checksums_hashes_order)
+if [ "$grepMatch" == "" ]; then
+  echo "Could not find hash algorith '$1' in checksums_hashes_order"
+  exit 1
+fi
+
+set -e
+
+lineNumber=$(echo "$grepMatch" | cut -f1 -d:)
+
+realLineNumber="$(($lineNumber + 1))"
+
+grep "$2" checksums | sed 's/  /\t/g' | cut -f1,$realLineNumber