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Diffstat (limited to 'gnulib-tests/test-select-stdin.c')
-rw-r--r-- | gnulib-tests/test-select-stdin.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/gnulib-tests/test-select-stdin.c b/gnulib-tests/test-select-stdin.c new file mode 100644 index 0000000..1182391 --- /dev/null +++ b/gnulib-tests/test-select-stdin.c @@ -0,0 +1,83 @@ +/* Test of select() substitute, reading from stdin. + Copyright (C) 2008-2023 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); + } + } +} |