usr/src/bin/stty/util.c

/*-
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)util.c      5.2 (Berkeley) %G%";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include "stty.h"
#include "extern.h"

/*
 * Gross, but since we're changing the control descriptor from 1 to 0, most
 * users will be probably be doing "stty > /dev/sometty" by accident.  If 1
 * and 2 are both ttys, but not the same, assume that 1 was incorrectly
 * redirected.
 */
void
checkredirect()
{
        struct stat sb1, sb2;

        if (isatty(STDOUT_FILENO) && isatty(STDERR_FILENO) &&
            !fstat(STDOUT_FILENO, &sb1) && !fstat(STDERR_FILENO, &sb2) &&
            (sb1.st_rdev != sb2.st_rdev))
warn("stdout appears redirected, but stdin is the control descriptor");
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)fprintf(stderr, "stty: ");
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        exit(1);
        /* NOTREACHED */
}

void
#if __STDC__
warn(const char *fmt, ...)
#else
warn(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)fprintf(stderr, "stty: ");
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
}