ucbcmd/sum/sum.c

	sum.c revision f22acdfff536d452df49dd85c5ecd42092b8fcad
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved. The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Sum bytes in file mod 2^16
 */

#include <stdio.h>

int
main(int argc, char **argv)
{
    unsigned int sum;
    int i, c;
    FILE *f;
    long long nbytes;
    int errflg = 0;

    i = 1;
    do {
        if (i < argc) {
            if ((f = fopen(argv[i], "r")) == NULL) {
                (void) fprintf(stderr,
                    "sum: Can't open %s\n", argv[i]);
                errflg += 10;
                continue;
            }
        } else
            f = stdin;
        sum = 0;
        nbytes = 0;
        while ((c = getc(f)) != EOF) {
            nbytes++;
            if (sum&01)
                sum = (sum>>1) + 0x8000;
            else
                sum >>= 1;
            sum += c;
            sum &= 0xFFFF;
        }
        if (ferror(f)) {
            errflg++;
            (void) fprintf(stderr,
                "sum: read error on %s\n",
                argc > 1 ? argv[i] : "-");
        }

        (void) printf("%05u %5lld", sum,
            (nbytes + BUFSIZ - 1) / BUFSIZ);
        if (argc > 2)
            (void) printf(" %s", argv[i]);
        (void) printf("\n");
        (void) fclose(f);
    } while (++i < argc);

    return (errflg);
}