buff-di-wuff: add pid file and startup-delay for non-interactive runsHEADmaster

1 files changed, 15 insertions, 0 deletions

diff --git a/buff-di-wuff b/buff-di-wuff
index 2be2f21..7a07d9d 100755
--- a/buff-di-wuff
+++ b/buff-di-wuff
@@ -2,6 +2,21 @@
 
 set -e
 
+pid_file="/tmp/${0##*/}.pid"
+if [ -f "${pid_file}" ] \
+&& kill -0 "$(cat "${pid_file}")" >/dev/null 2>&1; then
+  >&2 printf 'another %s is running as %s\n' "${0##*/}" "$(cat "${pid_file}")"
+  exit
+fi
+
+echo $$ \
+> "${pid_file}"
+trap 'rm "${pid_file}"' EXIT
+
+if ! tty -s; then
+  sleep $((${RANDOM} % 3600))
+fi
+
 cache_dir=$(readlink -e "$(dirname "$0")/../httpdocs")
 
 mkdir -p \