209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love/*
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * Copyright (c) 1991, 1993
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * The Regents of the University of California. All rights reserved.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * This code is derived from software contributed to Berkeley by
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * Edward Sze-Tyan Wang.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * Redistribution and use in source and binary forms, with or without
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * modification, are permitted provided that the following conditions
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * are met:
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * 1. Redistributions of source code must retain the above copyright
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * notice, this list of conditions and the following disclaimer.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * 2. Redistributions in binary form must reproduce the above copyright
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * notice, this list of conditions and the following disclaimer in the
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * documentation and/or other materials provided with the distribution.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * 4. Neither the name of the University nor the names of its contributors
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * may be used to endorse or promote products derived from this software
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * without specific prior written permission.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * SUCH DAMAGE.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love */
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <sys/types.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <sys/stat.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <err.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <errno.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <fcntl.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <stdio.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <stdlib.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <string.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <strings.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include <unistd.h>
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love#include "extern.h"
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love/*
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * bytes -- read bytes to an offset from the end and display.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * This is the function that reads to a byte offset from the end of the input,
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * storing the data in a wrap-around buffer which is then displayed. If the
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * rflag is set, the data is displayed in lines in reverse order, and this
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * routine has the usual nastiness of trying to find the newlines. Otherwise,
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * it is displayed from the character closest to the beginning of the input to
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * the end.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love */
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Loveint
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Lovebytes(FILE *fp, const char *fn, off_t off)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love{
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love int ch, len, tlen;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love char *ep, *p, *t;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love int wrap;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love char *sp;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if ((sp = p = malloc(off)) == NULL)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love err(1, "malloc");
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (wrap = 0, ep = p + off; (ch = getc(fp)) != EOF; ) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *p = ch;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (++p == ep) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love wrap = 1;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love p = sp;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (ferror(fp)) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love ierr(fn);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love free(sp);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love return (1);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (rflag) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (t = p - 1, len = 0; t >= sp; --t, ++len)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (*t == '\n' && len) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(t + 1, len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love len = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (wrap) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love tlen = len;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (t = ep - 1, len = 0; t >= p; --t, ++len)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (*t == '\n') {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (len) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(t + 1, len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love len = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (tlen) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(sp, tlen);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love tlen = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (len)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(t + 1, len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (tlen)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(sp, tlen);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love } else {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (wrap && (len = ep - p))
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(p, len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love len = p - sp;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (len)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(sp, len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love free(sp);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love return (0);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love}
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love/*
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * lines -- read lines to an offset from the end and display.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * This is the function that reads to a line offset from the end of the input,
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * storing the data in an array of buffers which is then displayed. If the
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * rflag is set, the data is displayed in lines in reverse order, and this
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * routine has the usual nastiness of trying to find the newlines. Otherwise,
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * it is displayed from the line closest to the beginning of the input to
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love * the end.
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love */
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Loveint
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Lovelines(FILE *fp, const char *fn, off_t off)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love{
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love struct {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love int blen;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love uint_t len;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love char *l;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love } *llines;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love int ch, rc;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love char *p, *sp;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love int blen, cnt, recno, wrap;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if ((llines = malloc(off * sizeof (*llines))) == NULL)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love err(1, "malloc");
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love bzero(llines, off * sizeof (*llines));
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love p = sp = NULL;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love blen = cnt = recno = wrap = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love rc = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love while ((ch = getc(fp)) != EOF) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (++cnt > blen) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if ((sp = realloc(sp, blen += 1024)) == NULL)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love err(1, "realloc");
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love p = sp + cnt - 1;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love *p++ = ch;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (ch == '\n') {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if ((int)llines[recno].blen < cnt) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love llines[recno].blen = cnt + 256;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if ((llines[recno].l = realloc(llines[recno].l,
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love llines[recno].blen)) == NULL)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love err(1, "realloc");
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love bcopy(sp, llines[recno].l, llines[recno].len = cnt);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love cnt = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love p = sp;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (++recno == off) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love wrap = 1;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love recno = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (ferror(fp)) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love ierr(fn);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love rc = 1;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love goto done;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (cnt) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love llines[recno].l = sp;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love sp = NULL;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love llines[recno].len = cnt;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (++recno == off) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love wrap = 1;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love recno = 0;
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (rflag) {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (cnt = recno - 1; cnt >= 0; --cnt)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(llines[cnt].l, llines[cnt].len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (wrap)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (cnt = off - 1; cnt >= recno; --cnt)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(llines[cnt].l, llines[cnt].len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love } else {
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love if (wrap)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (cnt = recno; cnt < off; ++cnt)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(llines[cnt].l, llines[cnt].len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (cnt = 0; cnt < recno; ++cnt)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love WR(llines[cnt].l, llines[cnt].len);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love }
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Lovedone:
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love for (cnt = 0; cnt < off; cnt++)
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love free(llines[cnt].l);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love free(sp);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love free(llines);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love return (rc);
209e49b2ff611e7d61ff58e13756ae67f51be550Chris Love}