cmd/tail/forward.c

	forward.c revision 05d495417696d1b637b12ffc2c027668de52c7a2
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica/*
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * Copyright (c) 1991, 1993
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  The Regents of the University of California.  All rights reserved.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * This code is derived from software contributed to Berkeley by
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * Edward Sze-Tyan Wang.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * Redistribution and use in source and binary forms, with or without
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * modification, are permitted provided that the following conditions
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * are met:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * 1. Redistributions of source code must retain the above copyright
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *    notice, this list of conditions and the following disclaimer.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * 2. Redistributions in binary form must reproduce the above copyright
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *    notice, this list of conditions and the following disclaimer in the
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *    documentation and/or other materials provided with the distribution.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * 4. Neither the name of the University nor the names of its contributors
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *    may be used to endorse or promote products derived from this software
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *    without specific prior written permission.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * SUCH DAMAGE.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica/*
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * Solaris porting notes:  the original FreeBSD version made use of the
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *                         BSD kqueue event notification framework; this
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *                         was changed to use usleep()
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/param.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/mount.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/types.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/stat.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/statfs.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/statvfs.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/time.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/mman.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <sys/poll.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <port.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <err.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <errno.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <fcntl.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <limits.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <stdio.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <stdlib.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <string.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include <unistd.h>
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#include "extern.h"
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic void rlines(FILE *, const char *fn, off_t, struct stat *);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic int show(file_info_t *);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic void set_events(file_info_t *files);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica/* defines for inner loop actions */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#define USE_SLEEP   0
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica#define ADD_EVENTS  2
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricaint action = USE_SLEEP;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic const file_info_t *last;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica/*
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * forward -- display the file, from an offset, forward.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * There are eight separate cases for this -- regular and non-regular
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * files, by bytes or lines and from the beginning or end of the file.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * FBYTES   byte offset from the beginning of the file
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  REG seek
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  NOREG   read, counting bytes
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * FLINES   line offset from the beginning of the file
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  REG read, counting lines
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  NOREG   read, counting lines
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * RBYTES   byte offset from the end of the file
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  REG seek
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  NOREG   cyclically read characters into a wrap-around buffer
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * RLINES
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  REG mmap the file and step back until reach the correct offset.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *  NOREG   cyclically read lines into a wrap-around array of buffers
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricavoid
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricaforward(FILE *fp, const char *fn, enum STYLE style, off_t off, struct stat *sbp)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica{
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    int ch;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    switch (style) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    case FBYTES:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (off == 0)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (S_ISREG(sbp->st_mode)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (sbp->st_size < off)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                off = sbp->st_size;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (fseeko(fp, off, SEEK_SET) == -1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        } else while (off--)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if ((ch = getc(fp)) == EOF) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (ferror(fp)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    case FLINES:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (off == 0)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        for (;;) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if ((ch = getc(fp)) == EOF) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (ferror(fp)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (ch == '\n' && !--off)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    case RBYTES:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (S_ISREG(sbp->st_mode)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (sbp->st_size >= off &&
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                fseeko(fp, -off, SEEK_END) == -1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        } else if (off == 0) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            while (getc(fp) != EOF)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (ferror(fp)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        } else
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (bytes(fp, fn, off))
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    case RLINES:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (S_ISREG(sbp->st_mode))
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (!off) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (fseeko(fp, (off_t)0, SEEK_END) == -1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            } else
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                rlines(fp, fn, off, sbp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        else if (off == 0) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            while (getc(fp) != EOF)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (ferror(fp)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        } else
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (lines(fp, fn, off))
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    default:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    while ((ch = getc(fp)) != EOF)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (putchar(ch) == EOF)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            oerr();
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if (ferror(fp)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    (void) fflush(stdout);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica}
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica/*
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * rlines -- display the last offset lines of the file.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic void
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricarlines(FILE *fp, const char *fn, off_t off, struct stat *sbp)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica{
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    struct mapinfo map;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    off_t curoff, size;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    int i;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if ((size = sbp->st_size) == 0)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    map.start = NULL;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    map.fd = fileno(fp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    map.mapoff = map.maxoff = size;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    /*
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica     * Last char is special, ignore whether newline or not. Note that
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica     * size == 0 is dealt with above, and size == 1 sets curoff to -1.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica     */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    curoff = size - 2;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    while (curoff >= 0) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (curoff < map.mapoff && maparound(&map, curoff) != 0) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        for (i = curoff - map.mapoff; i >= 0; i--)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (map.start[i] == '\n' && --off == 0)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        /* `i' is either the map offset of a '\n', or -1. */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        curoff = map.mapoff + i;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (i >= 0)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    curoff++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if (mapprint(&map, curoff, size - curoff) != 0) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        exit(1);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    /* Set the file pointer to reflect the length displayed. */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if (fseeko(fp, sbp->st_size, SEEK_SET) == -1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if (map.start != NULL && munmap(map.start, map.maplen)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        ierr(fn);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica}
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic int
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricashow(file_info_t *file)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica{
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    int ch;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    while ((ch = getc(file->fp)) != EOF) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (last != file && no_files > 1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (!qflag)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                (void) printf("\n==> %s <==\n",
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    file->file_name);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            last = file;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (putchar(ch) == EOF)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            oerr();
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    (void) fflush(stdout);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if (ferror(file->fp)) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        (void) fclose(file->fp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        file->fp = NULL;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        ierr(file->file_name);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        return (0);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    clearerr(file->fp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    return (1);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica}
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricastatic void
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricaset_events(file_info_t *files)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica{
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    int i;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    file_info_t *file;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    for (i = 0, file = files; i < no_files; i++, file++) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (! file->fp)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            continue;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        (void) fstat(fileno(file->fp), &file->st);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica}
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica/*
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica * follow -- display the file, from an offset, forward.
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica *
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricavoid
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01ricafollow(file_info_t *files, enum STYLE style, off_t off)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica{
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    int active, ev_change, i, n = -1;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    struct stat sb2;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    file_info_t *file;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    /* Position each of the files */
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    file = files;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    active = 0;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    n = 0;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    for (i = 0; i < no_files; i++, file++) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (file->fp) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            active = 1;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            n++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (no_files > 1 && !qflag)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                (void) printf("\n==> %s <==\n",
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    file->file_name);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            forward(file->fp, file->file_name, style, off,
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                &file->st);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (Fflag && fileno(file->fp) != STDIN_FILENO)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                n++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    if (!Fflag && !active)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        return;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    last = --file;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    set_events(files);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    for (;;) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        ev_change = 0;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (Fflag) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            for (i = 0, file = files; i < no_files; i++, file++) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (!file->fp) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    file->fp = fopen(file->file_name, "r");
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    if (file->fp != NULL &&
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        fstat(fileno(file->fp), &file->st)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        == -1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        (void) fclose(file->fp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        file->fp = NULL;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    if (file->fp != NULL)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        ev_change++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    continue;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (fileno(file->fp) == STDIN_FILENO)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    continue;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (stat(file->file_name, &sb2) == -1) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    if (errno != ENOENT)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        ierr(file->file_name);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    (void) show(file);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    (void) fclose(file->fp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    file->fp = NULL;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    ev_change++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    continue;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                if (sb2.st_ino != file->st.st_ino ||
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    sb2.st_dev != file->st.st_dev ||
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    sb2.st_nlink == 0) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    (void) show(file);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    file->fp = freopen(file->file_name, "r",
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        file->fp);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    if (file->fp != NULL)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        (void) memcpy(&file->st, &sb2,
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                            sizeof (struct stat));
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    else if (errno != ENOENT)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                        ierr(file->file_name);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                    ev_change++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        for (i = 0, file = files; i < no_files; i++, file++)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            if (file->fp && !show(file))
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica                ev_change++;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        if (ev_change)
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            set_events(files);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        switch (action) {
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        case USE_SLEEP:
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            (void) usleep(250000);
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica            break;
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica        }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica    }
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica}
f875b4ebb1dd9fdbeb043557cab38ab3bf7f6e01rica