From ab121f379a3cff458c90e6f480ba4bb68c8733dd Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Sat, 27 Nov 2010 07:49:17 +0100 Subject: Linux Device Drivers 3 examples --- misc-progs/nbtest.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 misc-progs/nbtest.c (limited to 'misc-progs/nbtest.c') diff --git a/misc-progs/nbtest.c b/misc-progs/nbtest.c new file mode 100644 index 0000000..6a0bd54 --- /dev/null +++ b/misc-progs/nbtest.c @@ -0,0 +1,44 @@ +/* + * nbtest.c: read and write in non-blocking mode + * This should run with any Unix + * + * Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet + * Copyright (C) 2001 O'Reilly & Associates + * + * The source code in this file can be freely used, adapted, + * and redistributed in source or binary form, so long as an + * acknowledgment appears in derived source files. The citation + * should list that the code comes from the book "Linux Device + * Drivers" by Alessandro Rubini and Jonathan Corbet, published + * by O'Reilly & Associates. No warranty is attached; + * we cannot take responsibility for errors or fitness for use. + */ + +#include +#include +#include +#include +#include + +char buffer[4096]; + +int main(int argc, char **argv) +{ + int delay = 1, n, m = 0; + + if (argc > 1) + delay=atoi(argv[1]); + fcntl(0, F_SETFL, fcntl(0,F_GETFL) | O_NONBLOCK); /* stdin */ + fcntl(1, F_SETFL, fcntl(1,F_GETFL) | O_NONBLOCK); /* stdout */ + + while (1) { + n = read(0, buffer, 4096); + if (n >= 0) + m = write(1, buffer, n); + if ((n < 0 || m < 0) && (errno != EAGAIN)) + break; + sleep(delay); + } + perror(n < 0 ? "stdin" : "stdout"); + exit(1); +} -- cgit v1.2.1-18-gbd029