Add JSON.pm to third_party

third_party/JSON/get_and_build_json_pm.sh

+#!/bin/bash
+# Download and build JSON.pm
+# Homepage:
+# http://search.cpan.org/~makamaka/JSON-2.58/lib/JSON.pm
+SRC_URL='http://www.cpan.org/authors/id/M/MA/MAKAMAKA/JSON-2.58.tar.gz'
+FILENAME="$(basename $SRC_URL)"
+SHA1_FILENAME="$FILENAME.sha1"
+BUILD_DIR='JSON-2.58'
+INSTALL_DIR="$(pwd)/out"
+
+curl --remote-name "$SRC_URL"
+
+# Check hash
+# SHA-1 hash generated via:
+# shasum JSON-2.58.tar.gz > JSON-2.58.tar.gz.sha1
+if ! [ -f "$SHA1_FILENAME" ]
+then
+  echo "SHA-1 hash file $SHA1_FILENAME not found, could not verify archive"
+  exit 1
+fi
+
+# Check that hash file contains hash for archive
+HASHFILE_REGEX="^[0-9a-f]{40}  $FILENAME"  # 40-digit hash, followed by filename
+if ! grep --extended-regex --line-regex --silent \
+  "$HASHFILE_REGEX" "$SHA1_FILENAME"
+then
+  echo "SHA-1 hash file $SHA1_FILENAME does not contain hash for $FILENAME," \
+       'could not verify archive'
+  echo 'Hash file contents are:'
+  cat "$SHA1_FILENAME"
+  exit 1
+fi
+
+if ! shasum --check "$SHA1_FILENAME"
+then
+  echo 'SHA-1 hash does not match,' \
+       "archive file $FILENAME corrupt or compromised!"
+  exit 1
+fi
+
+# Extract and build
+tar xvzf "$FILENAME"
+cd "$BUILD_DIR"
+perl Makefile.PL INSTALL_BASE="$INSTALL_DIR"
+make
+make test
+make install