58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
/*
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* asynctest.c: use async notification to read stdin
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*
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* Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
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* Copyright (C) 2001 O'Reilly & Associates
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*
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* The source code in this file can be freely used, adapted,
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* and redistributed in source or binary form, so long as an
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* acknowledgment appears in derived source files. The citation
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* should list that the code comes from the book "Linux Device
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* Drivers" by Alessandro Rubini and Jonathan Corbet, published
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* by O'Reilly & Associates. No warranty is attached;
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* we cannot take responsibility for errors or fitness for use.
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <signal.h>
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#include <fcntl.h>
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int gotdata=0;
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void sighandler(int signo)
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{
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if (signo==SIGIO)
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gotdata++;
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return;
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}
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char buffer[4096];
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int main(int argc, char **argv)
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{
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int count;
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struct sigaction action;
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memset(&action, 0, sizeof(action));
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action.sa_handler = sighandler;
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action.sa_flags = 0;
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sigaction(SIGIO, &action, NULL);
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fcntl(STDIN_FILENO, F_SETOWN, getpid());
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fcntl(STDIN_FILENO, F_SETFL, fcntl(STDIN_FILENO, F_GETFL) | FASYNC);
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while(1) {
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/* this only returns if a signal arrives */
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sleep(86400); /* one day */
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if (!gotdata)
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continue;
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count=read(0, buffer, 4096);
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/* buggy: if avail data is more than 4kbytes... */
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write(1,buffer,count);
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gotdata=0;
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}
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}
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