Assorted changes from Steve Dickson

[nfs-utils.git] / support / nfs / closeall.c

diff --git a/support/nfs/closeall.c b/support/nfs/closeall.c
new file mode 100644 (file)
index 0000000..cc7fb3b
--- /dev/null
+++ b/support/nfs/closeall.c
@@ -0,0 +1,31 @@
+/*
+ * 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);
+       }
+}