qrscan: init

krebs/5pkgs/simple/qrscan.nix

@@ -0,0 +1,27 @@
+{ coreutils, gnused, writeDashBin, zbar }:
+
+writeDashBin "qrscan" ''
+  set -efu
+
+  tmpdir=$(${coreutils}/bin/mktemp --tmpdir -d qrscan.XXXXXXXX)
+  codefile=$tmpdir/code
+
+  cleanup() {
+    ${coreutils}/bin/rm "$codefile"
+    ${coreutils}/bin/rmdir "$tmpdir"
+  }
+
+  ${coreutils}/bin/mkfifo "$codefile"
+
+  ${zbar}/bin/zbarcam > "$codefile" &
+  zbarcampid=$!
+
+  exec < "$codefile"
+  while read -r code; do
+    code=$(printf %s "$code" | ${gnused}/bin/sed -n 's/^QR-Code://p')
+    if test -n "$code"; then
+      ${coreutils}/bin/kill "$zbarcampid"
+      echo "$code"
+    fi
+  done
+''