1 files changed, 39 insertions, 0 deletions
diff --git a/wait_pid.c b/wait_pid.c
new file mode 100644
index 0000000..d7a7e84
--- /dev/null
+++ b/wait_pid.c
@@ -0,0 +1,39 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "error.h"
+#include "haswaitp.h"
+
+#ifdef HASWAITPID
+
+int wait_pid(wstat,pid) int *wstat; int pid;
+{
+  int r;
+
+  do
+    r = waitpid(pid,wstat,0);
+  while ((r == -1) && (errno == error_intr));
+  return r;
+}
+
+#else
+
+/* XXX untested */
+/* XXX breaks down with more than two children */
+static int oldpid = 0;
+static int oldwstat; /* defined if(oldpid) */
+
+int wait_pid(wstat,pid) int *wstat; int pid;
+{
+  int r;
+
+  if (pid == oldpid) { *wstat = oldwstat; oldpid = 0; return pid; }
+
+  do {
+    r = wait(wstat);
+    if ((r != pid) && (r != -1)) { oldwstat = *wstat; oldpid = r; continue; }
+  }
+  while ((r == -1) && (errno == error_intr));
+  return r;
+}
+
+#endif