message.c

unix环境高级编程的源代码

#include    "lprps.h"
#include    <ctype.h>

static char    msgbuf[MBSIZE];
static int    msgcnt;
static void    printer_flushing(void);

/* Called by proc_input_char() after it's seen the "%%[" that
 * starts a message. */

void
msg_init(void)
{
    msgcnt = 0;        /* count of chars in message buffer */
}

/* All characters received from the printer between the starting
 * %%[ and the terminating ]%% are placed into the message buffer
 * by proc_some_input().  This message will be examined by
 * proc_msg() below. */

void
msg_char(int c)
{
    if (c != '\0' && msgcnt < MBSIZE - 1)
        msgbuf[msgcnt++] = c;
}

/* This function is called by proc_input_char() only after the final
 * percent in a "%%[ <message> ]%%" has been seen.  It parses the
 * <message>, which consists of one or more "key: val" pairs.
 * If there are multiple pairs, "val" can end in a semicolon. */

void
proc_msg(void)
{
    char    *ptr, *key, *val;
    int        n;

    msgbuf[msgcnt] = 0;        /* null terminate message */
    for (ptr = strtok(msgbuf, ";"); ptr != NULL;
                                        ptr = strtok(NULL, ";")) {
        while (isspace(*ptr))
            ptr++;            /* skip leading spaces in key */
        key = ptr;

        if ( (ptr = strchr(ptr, ':')) == NULL)
            continue;    /* missing colon, something wrong, ignore */
        *ptr++ = '\0';    /* null terminate key (overwrite colon) */

        while (isspace(*ptr))
            ptr++;        /* skip leading spaces in val */
        val = ptr;
                        /* remove trailing spaces in val */
        ptr = strchr(val, '\0');
        while (ptr > val && isspace(ptr[-1]))
            --ptr;
        *ptr = '\0';

        if (strcmp(key, "Flushing") == 0) {
            printer_flushing();        /* never returns */

        } else if (strcmp(key, "PrinterError") == 0) {
            log_msg("proc_msg: printer error: %s", val);

        } else if (strcmp(key, "Error") == 0) {
              mail_line("Your PostScript printer job "
                      "produced the error `%s'.\n", val);

        } else if (strcmp(key, "status") == 0) {
            if (strcmp(val, "idle") == 0)
                status = IDLE;
            else if (strcmp(val, "busy") == 0)
                status = BUSY;
            else if (strcmp(val, "waiting") == 0)
                status = WAITING;
            else
                status = UNKNOWN;    /* "printing", "PrinterError",
                       "initializing", or "printing test page". */

        } else if (strcmp(key, "OffendingCommand") == 0) {
              mail_line("The offending command was `%s'.\n", val);

        } else if (strcmp(key, "pagecount") == 0) {
            if (sscanf(val, "%d", &n) == 1 && n >= 0) {
                  if (start_page < 0)
                    start_page = n;
                  else
                    end_page = n;
            }
        }
    }
}

/* Called only by proc_msg() when the "Flushing" message
 * is received from the printer.  We exit. */

static void
printer_flushing(void)
{
    clear_intr();            /* don't catch SIGINT */

    tty_flush();            /* empty tty input and output queues */
    block_write(&eofc, 1);    /* send an EOF to the printer */

    proc_upto_eof(1);        /* this call won't be recursive,
                               since we specify to ignore input */
    get_page(&end_page);
    do_acct();
    exit(EXIT_SUCCESS);
}