diff --git a/iasha1check b/iasha1check
index dbc4c95..2748b8a 100755
--- a/iasha1check
+++ b/iasha1check
@@ -1,3 +1,43 @@
 #!/bin/bash
 # Fetch the SHA-1 hashes from an IA item and ensure that they match the local files (i.e. that the upload was successful)
-identifier="$1"; escapedIdentifier="$(sed 's/[.[\*^$()+?{|]/\\&/g' <<<"${identifier}")"; sha1sum -c <(curl -sL "https://archive.org/download/${identifier}/${identifier}_files.xml" | tr -d '\n' | grep -Po '<file .*?</file>' | grep 'source="original".*<sha1>' | sed 's,^.*name=",,; s,".*<sha1>, ,; s,</sha1>.*$,,' | grep -Pv "^${escapedIdentifier}"'(\.cdx\.(gz|idx)|_meta\.(sqlite|xml)) ' | awk '{ print $2 "  " $1 }');
+
+identifier="$1"
+escapedIdentifier="$(sed 's/[.[\*^$()+?{|]/\\&/g' <<<"${identifier}")"
+readarray -t iasha1sums < <(curl -sL "https://archive.org/download/${identifier}/${identifier}_files.xml" | tr -d '\n' | grep -Po '<file .*?</file>' | grep 'source="original".*<sha1>' | sed 's,^.*name=",,; s,".*<sha1>, ,; s,</sha1>.*$,,' | grep -Pv "^${escapedIdentifier}"'(\.cdx\.(gz|idx)|_meta\.(sqlite|xml)) ' | awk '{ print $2 "  " $1 }')
+
+localFiles=()
+while IFS= read -r -d $'\0' f; do localFiles+=("${f:2}"); done < <(find . -type f -print0)
+readarray -t iaFiles < <(printf "%s\n" "${iasha1sums[@]}" | sed 's,^.\{40\}  ,,')
+readarray -t localFilesSorted < <(printf "%s\n" "${localFiles[@]}" | sort)
+readarray -t iaFilesSorted < <(printf "%s\n" "${iaFiles[@]}" | sort)
+readarray -t localMissing < <(comm -13 <(printf "%s\n" "${localFilesSorted[@]}") <(printf "%s\n" "${iaFilesSorted[@]}"))
+readarray -t iaMissing < <(comm -23 <(printf "%s\n" "${localFilesSorted[@]}") <(printf "%s\n" "${iaFilesSorted[@]}"))
+
+status=0
+
+if [[ ${#localMissing[@]} -eq 0 && ${#iaMissing[@]} -eq 0 ]]
+then
+	echo "File list comparison: OK"
+fi
+if [[ ${#iaMissing[@]} -gt 0 ]]
+then
+	echo "Local files that are not in the IA item:"
+	printf "  %s\n" "${iaMissing[@]}"
+	status=1
+fi
+if [[ ${#localMissing[@]} -gt 0 ]]
+then
+	echo "IA item files that are not in the local directory:"
+	printf "  %s\n" "${localMissing[@]}"
+	status=1
+fi
+
+echo "SHA-1 comparison:"
+sha1sum -c < <(printf "%s\n" "${iasha1sums[@]}") > >(sed 's,^,  ,') 2>&1
+if [[ $? -ne 0 ]]
+then
+	echo "SHA-1 comparison failed!"
+	status=1
+fi
+
+exit ${status}