316bdea082
after allocating a new buffer. This bug caused `tail -r < /dev/null' to core dump when the `J' malloc option is set, and also affected any other input that was an exact multiple of 128k.
288 lines
7.0 KiB
C
288 lines
7.0 KiB
C
/*-
|
|
* Copyright (c) 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* Edward Sze-Tyan Wang.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#if 0
|
|
#ifndef lint
|
|
static char sccsid[] = "@(#)reverse.c 8.1 (Berkeley) 6/6/93";
|
|
#endif /* not lint */
|
|
#endif
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/mman.h>
|
|
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <limits.h>
|
|
#include <stdint.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "extern.h"
|
|
|
|
static void r_buf(FILE *);
|
|
static void r_reg(FILE *, enum STYLE, off_t, struct stat *);
|
|
|
|
/*
|
|
* reverse -- display input in reverse order by line.
|
|
*
|
|
* There are six separate cases for this -- regular and non-regular
|
|
* files by bytes, lines or the whole file.
|
|
*
|
|
* BYTES display N bytes
|
|
* REG mmap the file and display the lines
|
|
* NOREG cyclically read characters into a wrap-around buffer
|
|
*
|
|
* LINES display N lines
|
|
* REG mmap the file and display the lines
|
|
* NOREG cyclically read lines into a wrap-around array of buffers
|
|
*
|
|
* FILE display the entire file
|
|
* REG mmap the file and display the lines
|
|
* NOREG cyclically read input into a linked list of buffers
|
|
*/
|
|
void
|
|
reverse(FILE *fp, enum STYLE style, off_t off, struct stat *sbp)
|
|
{
|
|
if (style != REVERSE && off == 0)
|
|
return;
|
|
|
|
if (S_ISREG(sbp->st_mode))
|
|
r_reg(fp, style, off, sbp);
|
|
else
|
|
switch(style) {
|
|
case FBYTES:
|
|
case RBYTES:
|
|
bytes(fp, off);
|
|
break;
|
|
case FLINES:
|
|
case RLINES:
|
|
lines(fp, off);
|
|
break;
|
|
case REVERSE:
|
|
r_buf(fp);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* r_reg -- display a regular file in reverse order by line.
|
|
*/
|
|
static void
|
|
r_reg(FILE *fp, enum STYLE style, off_t off, struct stat *sbp)
|
|
{
|
|
struct mapinfo map;
|
|
off_t curoff, size, lineend;
|
|
int i;
|
|
|
|
if (!(size = sbp->st_size))
|
|
return;
|
|
|
|
map.start = NULL;
|
|
map.mapoff = map.maxoff = size;
|
|
map.fd = fileno(fp);
|
|
|
|
/*
|
|
* Last char is special, ignore whether newline or not. Note that
|
|
* size == 0 is dealt with above, and size == 1 sets curoff to -1.
|
|
*/
|
|
curoff = size - 2;
|
|
lineend = size;
|
|
while (curoff >= 0) {
|
|
if (curoff < map.mapoff ||
|
|
curoff >= map.mapoff + (off_t)map.maplen) {
|
|
if (maparound(&map, curoff) != 0) {
|
|
ierr();
|
|
return;
|
|
}
|
|
}
|
|
for (i = curoff - map.mapoff; i >= 0; i--) {
|
|
if (style == RBYTES && --off == 0)
|
|
break;
|
|
if (map.start[i] == '\n')
|
|
break;
|
|
}
|
|
/* `i' is either the map offset of a '\n', or -1. */
|
|
curoff = map.mapoff + i;
|
|
if (i < 0)
|
|
continue;
|
|
|
|
/* Print the line and update offsets. */
|
|
if (mapprint(&map, curoff + 1, lineend - curoff - 1) != 0) {
|
|
ierr();
|
|
return;
|
|
}
|
|
lineend = curoff + 1;
|
|
curoff--;
|
|
|
|
if (style == RLINES)
|
|
off--;
|
|
|
|
if (off == 0 && style != REVERSE) {
|
|
/* Avoid printing anything below. */
|
|
curoff = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (curoff < 0 && mapprint(&map, 0, lineend) != 0) {
|
|
ierr();
|
|
return;
|
|
}
|
|
if (map.start != NULL && munmap(map.start, map.maplen))
|
|
ierr();
|
|
}
|
|
|
|
typedef struct bf {
|
|
struct bf *next;
|
|
struct bf *prev;
|
|
int len;
|
|
char *l;
|
|
} BF;
|
|
|
|
/*
|
|
* r_buf -- display a non-regular file in reverse order by line.
|
|
*
|
|
* This is the function that saves the entire input, storing the data in a
|
|
* doubly linked list of buffers and then displays them in reverse order.
|
|
* It has the usual nastiness of trying to find the newlines, as there's no
|
|
* guarantee that a newline occurs anywhere in the file, let alone in any
|
|
* particular buffer. If we run out of memory, input is discarded (and the
|
|
* user warned).
|
|
*/
|
|
static void
|
|
r_buf(FILE *fp)
|
|
{
|
|
BF *mark, *tl, *tr;
|
|
int ch, len, llen;
|
|
char *p;
|
|
off_t enomem;
|
|
|
|
#define BSZ (128 * 1024)
|
|
for (mark = NULL, enomem = 0;;) {
|
|
/*
|
|
* Allocate a new block and link it into place in a doubly
|
|
* linked list. If out of memory, toss the LRU block and
|
|
* keep going.
|
|
*/
|
|
if (enomem || (tl = malloc(sizeof(BF))) == NULL ||
|
|
(tl->l = malloc(BSZ)) == NULL) {
|
|
if (!mark)
|
|
err(1, "malloc");
|
|
tl = enomem ? tl->next : mark;
|
|
enomem += tl->len;
|
|
} else if (mark) {
|
|
tl->next = mark;
|
|
tl->prev = mark->prev;
|
|
mark->prev->next = tl;
|
|
mark->prev = tl;
|
|
} else {
|
|
mark = tl;
|
|
mark->next = mark->prev = mark;
|
|
}
|
|
|
|
/* Fill the block with input data. */
|
|
for (p = tl->l, len = 0;
|
|
len < BSZ && (ch = getc(fp)) != EOF; ++len)
|
|
*p++ = ch;
|
|
|
|
if (ferror(fp)) {
|
|
ierr();
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If no input data for this block and we tossed some data,
|
|
* recover it.
|
|
*/
|
|
if (!len && enomem) {
|
|
enomem -= tl->len;
|
|
tl = tl->prev;
|
|
break;
|
|
}
|
|
|
|
tl->len = len;
|
|
if (ch == EOF)
|
|
break;
|
|
}
|
|
|
|
if (enomem) {
|
|
warnx("warning: %jd bytes discarded", (intmax_t)enomem);
|
|
rval = 1;
|
|
}
|
|
|
|
/*
|
|
* Step through the blocks in the reverse order read. The last char
|
|
* is special, ignore whether newline or not.
|
|
*/
|
|
for (mark = tl;;) {
|
|
for (p = tl->l + (len = tl->len) - 1, llen = 0; len--;
|
|
--p, ++llen)
|
|
if (*p == '\n') {
|
|
if (llen) {
|
|
WR(p + 1, llen);
|
|
llen = 0;
|
|
}
|
|
if (tl == mark)
|
|
continue;
|
|
for (tr = tl->next; tr->len; tr = tr->next) {
|
|
WR(tr->l, tr->len);
|
|
tr->len = 0;
|
|
if (tr == mark)
|
|
break;
|
|
}
|
|
}
|
|
tl->len = llen;
|
|
if ((tl = tl->prev) == mark)
|
|
break;
|
|
}
|
|
tl = tl->next;
|
|
if (tl->len) {
|
|
WR(tl->l, tl->len);
|
|
tl->len = 0;
|
|
}
|
|
while ((tl = tl->next)->len) {
|
|
WR(tl->l, tl->len);
|
|
tl->len = 0;
|
|
}
|
|
}
|