1 files changed, 83 insertions, 0 deletions
diff --git a/src/grep/gnulib-tests/test-select-stdin.c b/src/grep/gnulib-tests/test-select-stdin.c
new file mode 100644
index 0000000..26ca8a8
--- /dev/null
+++ b/src/grep/gnulib-tests/test-select-stdin.c
@@ -0,0 +1,83 @@
+/* Test of select() substitute, reading from stdin.
+   Copyright (C) 2008-2021 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2008.  */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include "macros.h"
+
+int
+main (void)
+{
+  printf ("Applying select() from standard input. Press Ctrl-C to abort.\n");
+  for (;;)
+    {
+      struct timeval before;
+      struct timeval after;
+      unsigned long spent_usec;
+      fd_set readfds;
+      struct timeval timeout;
+      int ret;
+
+      gettimeofday (&before, NULL);
+
+      FD_ZERO (&readfds);
+      FD_SET (0, &readfds);
+      timeout.tv_sec = 0;
+      timeout.tv_usec = 500000;
+      ret = select (1, &readfds, NULL, NULL, &timeout);
+
+      gettimeofday (&after, NULL);
+      spent_usec = (after.tv_sec - before.tv_sec) * 1000000
+                   + after.tv_usec - before.tv_usec;
+
+      if (ret < 0)
+        {
+          perror ("select failed");
+          exit (1);
+        }
+      if ((ret == 0) != ! FD_ISSET (0, &readfds))
+        {
+          fprintf (stderr, "incorrect return value\n");
+          exit (1);
+        }
+      if (ret == 0)
+        {
+          if (spent_usec < 250000)
+            {
+              fprintf (stderr, "returned too early\n");
+              exit (1);
+            }
+          /* Timeout */
+          printf (".");
+          ASSERT (fflush (stdout) == 0);
+        }
+      else
+        {
+          char c;
+
+          printf ("Input available! Trying to read 1 byte...\n");
+          ASSERT (read (0, &c, 1) == 1);
+        }
+    }
+}