Return to head.c CVS log

Up to [CSRG BSD Unix] / 43BSDReno / usr.bin / head

Annotation of 43BSDReno/usr.bin/head/head.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1980, 1987 Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * Redistribution and use in source and binary forms are permitted
        !             6:  * provided that: (1) source distributions retain this entire copyright
        !             7:  * notice and comment, and (2) distributions including binaries display
        !             8:  * the following acknowledgement:  ``This product includes software
        !             9:  * developed by the University of California, Berkeley and its contributors''
        !            10:  * in the documentation or other materials provided with the distribution
        !            11:  * and in all advertising materials mentioning features or use of this
        !            12:  * software. Neither the name of the University nor the names of its
        !            13:  * contributors may be used to endorse or promote products derived
        !            14:  * from this software without specific prior written permission.
        !            15:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            16:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            17:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            18:  */
        !            19: 
        !            20: #ifndef lint
        !            21: char copyright[] =
        !            22: "@(#) Copyright (c) 1980, 1987 Regents of the University of California.\n\
        !            23:  All rights reserved.\n";
        !            24: #endif /* not lint */
        !            25: 
        !            26: #ifndef lint
        !            27: static char sccsid[] = "@(#)head.c     5.5 (Berkeley) 6/1/90";
        !            28: #endif /* not lint */
        !            29: 
        !            30: #include <stdio.h>
        !            31: #include <ctype.h>
        !            32: /*
        !            33:  * head - give the first few lines of a stream or of each of a set of files
        !            34:  *
        !            35:  * Bill Joy UCB August 24, 1977
        !            36:  */
        !            37: 
        !            38: main(argc, argv)
        !            39:        int     argc;
        !            40:        char    **argv;
        !            41: {
        !            42:        register int    ch, cnt;
        !            43:        int     firsttime, linecnt = 10;
        !            44: 
        !            45:        if (argc > 1 && argv[1][0] == '-') {
        !            46:                if (!isdigit(argv[1][1])) {
        !            47:                        fprintf(stderr, "head: illegal option -- %c\n", argv[1][1]);
        !            48:                        goto usage;
        !            49:                }
        !            50:                if ((linecnt = atoi(argv[1] + 1)) < 0) {
        !            51: usage:                 fputs("usage: head [-line_count] [file ...]\n", stderr);
        !            52:                        exit(1);
        !            53:                }
        !            54:                --argc; ++argv;
        !            55:        }
        !            56:        /* setlinebuf(stdout); */
        !            57:        for (firsttime = 1, --argc, ++argv;; firsttime = 0) {
        !            58:                if (!*argv) {
        !            59:                        if (!firsttime)
        !            60:                                exit(0);
        !            61:                }
        !            62:                else {
        !            63:                        if (!freopen(*argv, "r", stdin)) {
        !            64:                                fprintf(stderr, "head: can't read %s.\n", *argv);
        !            65:                                exit(1);
        !            66:                        }
        !            67:                        if (argc > 1) {
        !            68:                                if (!firsttime)
        !            69:                                        putchar('\n');
        !            70:                                printf("==> %s <==\n", *argv);
        !            71:                        }
        !            72:                        ++argv;
        !            73:                }
        !            74:                for (cnt = linecnt; cnt; --cnt)
        !            75:                        while ((ch = getchar()) != EOF)
        !            76:                                if (putchar(ch) == '\n')
        !            77:                                        break;
        !            78:        }
        !            79:        /*NOTREACHED*/
        !            80: }

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.