sbin/init.chmr/fake_syslog.c

/*
 * Warning: extremely XXX
 * fake syslog to write to stderr, for standalone test version of init
 */


#ifdef FAKE_SYSLOG


#include <unistd.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#include <sys/file.h>


#ifdef TESTRUN
#  define FAKE_LOGFILE  "/dev/tty"
#else
#  define FAKE_LOGFILE  "/dev/console"
#endif


static char     *
itoa(i)
        int     i;
{
        static char     buf[12];
        char            *s;
        int             minflg = 0;

        s = &buf[11];
        *s = '\0';
        if (i < 0)
                minflg = 1, i = -i;
        do {
                *(--s) = (i % 10) + '0';
                i /= 10;
        } while (i);
        if (minflg)
                *(--s) = '-';
        return(s);
}


static int               _log_fd = 2;
static const char       *_log_id = "";


void
openlog(ident, logopt, facility)
const char      *ident;
int             logopt, facility;
{
        if (ident)
                _log_id = ident;
        if (_log_fd >= 0)
                close(_log_fd);
        _log_fd = open(FAKE_LOGFILE, O_WRONLY | O_NONBLOCK, 0);
}


void
vsyslog(int pri, const char *fmt, va_list ap)
{
        const char      *s, *t;
        int             saved_errno = errno;

        if (write(_log_fd, "", 0) < 0)
                openlog(NULL, 0, 0);
        write(_log_fd, _log_id, strlen(_log_id));
        if (*_log_id) write(_log_fd, ": ", 2);
        for (s=fmt; *s; s++)
                if (*s == '%')
                        switch (*(++s)) {
                                case '\0':
                                        s--; break;
                                case '%':
                                        write(_log_fd, s, 1); break;
                                case 's':
                                        t = va_arg(ap, char *);
                                        write(_log_fd, t, strlen(t));
                                        break;
                                case 'm':
#ifdef SMALL
                                        write(_log_fd, "Error ", 6);
                                        t = itoa(saved_errno);
#else
                                        t = strerror(saved_errno);
#endif
                                        write(_log_fd, t, strlen(t));
                                        break;
                                case 'd':
                                        t = itoa(va_arg(ap, int));
                                        write(_log_fd, t, strlen(t));
                                        break;
                                default:
                                        write(_log_fd, s-1, 2);
                        }
                else
                        write(_log_fd, s, 1);
        write(_log_fd, "\n", 1);
}


void
syslog(int pri, const char *fmt, ...)
{
va_list         ap;

        va_start(ap, fmt);
        vsyslog(pri, fmt, ap);
        va_end(ap);
}


void
closelog(void)
{
        close(_log_fd);
        _log_fd = -1;
}


#endif