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-rw-r--r--libc/manual/examples/select.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/libc/manual/examples/select.c b/libc/manual/examples/select.c
new file mode 100644
index 000000000..a65ed7750
--- /dev/null
+++ b/libc/manual/examples/select.c
@@ -0,0 +1,41 @@
+/*@group*/
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/time.h>
+/*@end group*/
+
+/*@group*/
+int
+input_timeout (int filedes, unsigned int seconds)
+{
+ fd_set set;
+ struct timeval timeout;
+/*@end group*/
+
+ /* Initialize the file descriptor set. */
+ FD_ZERO (&set);
+ FD_SET (filedes, &set);
+
+ /* Initialize the timeout data structure. */
+ timeout.tv_sec = seconds;
+ timeout.tv_usec = 0;
+
+/*@group*/
+ /* @code{select} returns 0 if timeout, 1 if input available, -1 if error. */
+ return TEMP_FAILURE_RETRY (select (FD_SETSIZE,
+ &set, NULL, NULL,
+ &timeout));
+}
+/*@end group*/
+
+/*@group*/
+int
+main (void)
+{
+ fprintf (stderr, "select returned %d.\n",
+ input_timeout (STDIN_FILENO, 5));
+ return 0;
+}
+/*@end group*/