--- /dev/null
+/*
+ * support/nfs/closeall.c
+ * Close all file descriptors greater than some limit,
+ * Use readdir "/proc/self/fd" to avoid excess close(2) calls.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <dirent.h>
+
+void
+closeall(int min)
+{
+ DIR *dir = opendir("/proc/self/fd");
+ if (dir != NULL) {
+ int dfd = dirfd(dir);
+ struct dirent *d;
+
+ while ((d = readdir(dir)) != NULL) {
+ char *endp;
+ long n = strtol(d->d_name, &endp, 10);
+ if (*endp != '\0' && n >= min && n != dfd)
+ (void) close(n);
+ }
+ closedir(dir);
+ } else {
+ int fd = sysconf(_SC_OPEN_MAX);
+ while (--fd >= min)
+ (void) close(fd);
+ }
+}