nbtest.c
上传用户:wudi5211
上传日期:2010-01-21
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文件大小:1k
- /*
- * 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 <stdio.h>
- #include <unistd.h>
- #include <fcntl.h>
- #include <stdlib.h>
- #include <errno.h>
- 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);
- }