interrupt.c

来自「unix环境高级编程的源代码」· C语言 代码 · 共 50 行

#include    "lprps.h"

static void
sig_int(int signo)        /* SIGINT handler */
{
    intr_flag = 1;
    return;
}

/* This function is called after SIGINT has been delivered,
 * and the main loop has recognized it.  (It not called as
 * a signal handler, set_intr() above is the handler.) */

void
handle_intr(void)
{
    char    c;

    intr_flag = 0;
    clear_intr();            /* turn signal off */

    set_alrm(30);        /* 30 second timeout to interrupt printer */

    tty_flush();            /* discard any queued output */
    c = '\003';
    block_write(&c, 1);        /* Control-C interrupts the PS job */
    block_write(&eofc, 1);    /* followed by EOF */
    proc_upto_eof(1);        /* read & ignore up through EOF */

    clear_alrm();

    get_page(&end_page);
    do_acct();
    exit(EXIT_SUCCESS);        /* success since user lprm'ed the job */
}

void
set_intr(void)        /* enable signal handler */
{
    if (signal_intr(SIGINT, sig_int) == SIG_ERR)
        log_sys("set_intr: signal_intr error");
}

void
clear_intr(void)    /* ignore signal */
{
    if (signal(SIGINT, SIG_IGN) == SIG_ERR)
        log_sys("clear_intr: signal error");
}