usr/src/usr.bin/tee/tee.c

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)tee.c       5.5 (Berkeley) %G%";
#endif /* not lint */

#include <sys/types.h>
#include <sys/file.h>
#include <signal.h>
#include <stdio.h>

main(argc, argv)
        int argc;
        char **argv;
{
        extern int optind;
        register int cnt, n, step;
        int append, ch, *fd;
        char buf[8192], *malloc();
        off_t lseek();

        append = 0;
        while ((ch = getopt(argc, argv, "ai")) != EOF)
                switch((char)ch) {
                case 'a':
                        append = 1;
                        break;
                case 'i':
                        (void)signal(SIGINT, SIG_IGN);
                        break;
                case '?':
                default:
                        fprintf(stderr, "usage: tee [-ai] [file ...]\n");
                        exit(2);
                }
        argv += optind;
        argc -= optind;

        if (!(fd = (int *)malloc((u_int)((argc + 1) * sizeof(int))))) {
                fprintf(stderr, "tee: out of space.\n");
                exit(2);
        }
        fd[0] = 1;                      /* always write to stdout */
        for (cnt = 1; *argv; ++argv)
                if ((fd[cnt] = open(*argv, append ? O_WRONLY|O_CREAT :
                    O_WRONLY|O_CREAT|O_TRUNC, 0600)) < 0) {
                        fprintf(stderr, "tee: %s: ", *argv);
                        perror((char *)NULL);
                }
                else {
                        if (append)
                                (void)lseek(fd[cnt], 0L, L_XTND);
                        ++cnt;
                }
        for (--cnt; (n = read(0, buf, sizeof(buf))) > 0;)
                for (step = cnt; step >= 0; --step)
                        (void)write(fd[step], buf, n);
        exit(0);
}