[#767] Added a warning when ps -p bugs

diff --git a/configure.ac b/configure.ac
index b6e4195d069cbcd48d17fd2d6d9c59cd41630202..aa641578de257c8db059c5db24a1e91b3cac3b21 100755 (executable)
--- a/configure.ac
+++ b/configure.ac
@@ -67,6 +67,12 @@ AC_SUBST(SEP)
 # pkg-config can be required.
 AC_PATH_PROG([PKG_CONFIG], [pkg-config])
 
+# check against BusyBox ps not supporting ps -p.
+ps -p 1234 2>&1 > /dev/null | grep 'unrecognized option: p'
+if test $? -eq 0; then
+       AC_MSG_WARN("ps does not support -p. It is likely the BusyBox ps: please install a full ps like procps")
+fi
+
 # Enable low-performing debugging facilities? This option optionally
 # enables some debugging aids that perform slowly and hence aren't built
 # by default.