1 /*
   2  * Copyright (c) 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  */
  30 
  31 
  32 #define WR(p, size) do { \
  33         if (write(STDOUT_FILENO, p, size) != (ssize_t)size) \
  34                 oerr(); \
  35         } while (0)
  36 
  37 #define TAILMAPLEN (4<<20)
  38 
  39 struct mapinfo {
  40         off_t   mapoff;
  41         off_t   maxoff;
  42         size_t  maplen;
  43         char    *start;
  44         int     fd;
  45 };
  46 
  47 struct file_info {
  48         FILE *fp;
  49         char *file_name;
  50         struct stat st;
  51 };
  52 
  53 typedef struct file_info file_info_t;
  54 
  55 enum STYLE { NOTSET = 0, FBYTES, FLINES, RBYTES, RLINES, REVERSE };
  56 
  57 void follow(file_info_t *, enum STYLE, off_t);
  58 void forward(FILE *, const char *, enum STYLE, off_t, struct stat *);
  59 void reverse(FILE *, const char *, enum STYLE, off_t, struct stat *);
  60 
  61 int bytes(FILE *, const char *, off_t);
  62 int lines(FILE *, const char *, off_t);
  63 
  64 void ierr(const char *);
  65 void oerr(void);
  66 int mapprint(struct mapinfo *, off_t, off_t);
  67 int maparound(struct mapinfo *, off_t);
  68 
  69 extern int Fflag, fflag, qflag, rflag, rval, no_files;