File: [local] / src / usr.bin / col / col.c (download)
Revision 1.18, Mon Oct 5 06:04:18 2015 UTC (8 years, 8 months ago) by deraadt
Branch: MAIN
Changes since 1.17: +4 -1 lines
col can be locked down with tame "stdio", in case it is fed nasty input,
or if it has bugs. The previous commits by schwarze indicate the latter
case was very true until recently...
ok doug
|
/* $OpenBSD: col.c,v 1.18 2015/10/05 06:04:18 deraadt Exp $ */
/* $NetBSD: col.c,v 1.7 1995/09/02 05:48:50 jtc Exp $ */
/*-
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Michael Rendell of the Memorial University of Newfoundland.
*
* 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. 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.
*/
#include <ctype.h>
#include <err.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <limits.h>
#define BS '\b' /* backspace */
#define TAB '\t' /* tab */
#define SPACE ' ' /* space */
#define NL '\n' /* newline */
#define CR '\r' /* carriage return */
#define ESC '\033' /* escape */
#define SI '\017' /* shift in to normal character set */
#define SO '\016' /* shift out to alternate character set */
#define VT '\013' /* vertical tab (aka reverse line feed) */
/* build up at least this many lines before flushing them out */
#define BUFFER_MARGIN 32
typedef char CSET;
typedef struct char_str {
#define CS_NORMAL 1
#define CS_ALTERNATE 2
size_t c_column; /* column character is in */
CSET c_set; /* character set (currently only 2) */
char c_char; /* character in question */
} CHAR;
typedef struct line_str LINE;
struct line_str {
CHAR *l_line; /* characters on the line */
LINE *l_prev; /* previous line */
LINE *l_next; /* next line */
size_t l_lsize; /* allocated sizeof l_line */
size_t l_line_len; /* strlen(l_line) */
size_t l_max_col; /* max column in the line */
int l_needs_sort; /* set if chars went in out of order */
};
void addto_lineno(int *, int);
LINE *alloc_line(void);
void dowarn(int);
void flush_line(LINE *);
void flush_lines(int);
void flush_blanks(void);
void free_line(LINE *);
void usage(void);
void *xreallocarray(void *, size_t, size_t);
CSET last_set; /* char_set of last char printed */
LINE *lines;
int compress_spaces; /* if doing space -> tab conversion */
int fine; /* if `fine' resolution (half lines) */
int max_bufd_lines; /* max # of half lines to keep in memory */
int nblank_lines; /* # blanks after last flushed line */
int no_backspaces; /* if not to output any backspaces */
#define PUTC(ch) \
if (putchar(ch) == EOF) \
err(1, "stdout");
int
main(int argc, char *argv[])
{
int ch;
CHAR *c;
CSET cur_set; /* current character set */
LINE *l; /* current line */
int extra_lines; /* # of lines above first line */
size_t cur_col; /* current column */
int cur_line; /* line number of current position */
int max_line; /* max value of cur_line */
int this_line; /* line l points to */
int nflushd_lines; /* number of lines that were flushed */
int adjust, opt, warned;
const char *errstr;
if (tame("stdio", NULL) == -1)
err(1, "tame");
max_bufd_lines = 256;
compress_spaces = 1; /* compress spaces into tabs */
while ((opt = getopt(argc, argv, "bfhl:x")) != -1)
switch (opt) {
case 'b': /* do not output backspaces */
no_backspaces = 1;
break;
case 'f': /* allow half forward line feeds */
fine = 1;
break;
case 'h': /* compress spaces into tabs */
compress_spaces = 1;
break;
case 'l': /* buffered line count */
max_bufd_lines = strtonum(optarg, 1,
(INT_MAX - BUFFER_MARGIN) / 2, &errstr) * 2;
if (errstr != NULL)
errx(1, "bad -l argument, %s: %s", errstr,
optarg);
break;
case 'x': /* do not compress spaces into tabs */
compress_spaces = 0;
break;
case '?':
default:
usage();
}
if (optind != argc)
usage();
adjust = extra_lines = warned = 0;
cur_col = 0;
cur_line = max_line = nflushd_lines = this_line = 0;
cur_set = last_set = CS_NORMAL;
lines = l = alloc_line();
while ((ch = getchar()) != EOF) {
if (!isgraph(ch)) {
switch (ch) {
case BS: /* can't go back further */
if (cur_col == 0)
continue;
--cur_col;
continue;
case CR:
cur_col = 0;
continue;
case ESC: /* just ignore EOF */
/*
* In the input stream, accept both the
* XPG5 sequences ESC-digit and the
* traditional BSD sequences ESC-ctrl.
*/
switch(getchar()) {
case '7': /* reverse line feed */
/* FALLTHROUGH */
case '\007':
addto_lineno(&cur_line, -2);
break;
case '8': /* reverse half-line feed */
/* FALLTHROUGH */
case '\010':
addto_lineno(&cur_line, -1);
break;
case '9': /* forward half-line feed */
/* FALLTHROUGH */
case '\011':
addto_lineno(&cur_line, 1);
if (cur_line > max_line)
max_line = cur_line;
}
continue;
case NL:
addto_lineno(&cur_line, 2);
if (cur_line > max_line)
max_line = cur_line;
cur_col = 0;
continue;
case SPACE:
++cur_col;
continue;
case SI:
cur_set = CS_NORMAL;
continue;
case SO:
cur_set = CS_ALTERNATE;
continue;
case TAB: /* adjust column */
cur_col |= 7;
++cur_col;
continue;
case VT:
addto_lineno(&cur_line, -2);
continue;
}
continue;
}
/* Must stuff ch in a line - are we at the right one? */
if (cur_line + adjust != this_line) {
LINE *lnew;
/* round up to next line */
adjust = !fine && (cur_line & 1);
if (cur_line + adjust < this_line) {
while (cur_line + adjust < this_line &&
l->l_prev != NULL) {
l = l->l_prev;
this_line--;
}
if (cur_line + adjust < this_line) {
if (nflushd_lines == 0) {
/*
* Allow backup past first
* line if nothing has been
* flushed yet.
*/
while (cur_line + adjust
< this_line) {
lnew = alloc_line();
l->l_prev = lnew;
lnew->l_next = l;
l = lines = lnew;
extra_lines++;
this_line--;
}
} else {
if (!warned++)
dowarn(cur_line);
cur_line = this_line - adjust;
}
}
} else {
/* may need to allocate here */
while (cur_line + adjust > this_line) {
if (l->l_next == NULL) {
l->l_next = alloc_line();
l->l_next->l_prev = l;
}
l = l->l_next;
this_line++;
}
}
if (this_line > nflushd_lines &&
this_line - nflushd_lines >=
max_bufd_lines + BUFFER_MARGIN) {
if (extra_lines) {
flush_lines(extra_lines);
extra_lines = 0;
}
flush_lines(this_line - nflushd_lines -
max_bufd_lines);
nflushd_lines = this_line - max_bufd_lines;
}
}
/* grow line's buffer? */
if (l->l_line_len + 1 >= l->l_lsize) {
size_t need;
need = l->l_lsize ? l->l_lsize : 45;
l->l_line = xreallocarray(l->l_line,
need, 2 * sizeof(CHAR));
l->l_lsize = need * 2;
}
c = &l->l_line[l->l_line_len++];
c->c_char = ch;
c->c_set = cur_set;
c->c_column = cur_col;
/*
* If things are put in out of order, they will need sorting
* when it is flushed.
*/
if (cur_col < l->l_max_col)
l->l_needs_sort = 1;
else
l->l_max_col = cur_col;
cur_col++;
}
if (extra_lines)
flush_lines(extra_lines);
/* goto the last line that had a character on it */
for (; l->l_next; l = l->l_next)
this_line++;
flush_lines(this_line - nflushd_lines + 1);
/* make sure we leave things in a sane state */
if (last_set != CS_NORMAL)
PUTC(SI);
/* flush out the last few blank lines */
if (max_line > this_line)
nblank_lines = max_line - this_line;
if (max_line & 1)
nblank_lines++;
flush_blanks();
exit(0);
}
void
flush_lines(int nflush)
{
LINE *l;
while (--nflush >= 0) {
l = lines;
lines = l->l_next;
if (l->l_line) {
flush_blanks();
flush_line(l);
}
if (l->l_line || l->l_next)
nblank_lines++;
if (l->l_line)
(void)free((void *)l->l_line);
free_line(l);
}
if (lines)
lines->l_prev = NULL;
}
/*
* Print a number of newline/half newlines. If fine flag is set, nblank_lines
* is the number of half line feeds, otherwise it is the number of whole line
* feeds.
*/
void
flush_blanks(void)
{
int half, i, nb;
half = 0;
nb = nblank_lines;
if (nb & 1) {
if (fine)
half = 1;
else
nb++;
}
nb /= 2;
for (i = nb; --i >= 0;)
PUTC('\n');
if (half) {
/*
* In the output stream, always generate
* escape sequences conforming to XPG5.
*/
PUTC(ESC);
PUTC('9');
if (!nb)
PUTC('\r');
}
nblank_lines = 0;
}
/*
* Write a line to stdout taking care of space to tab conversion (-h flag)
* and character set shifts.
*/
void
flush_line(LINE *l)
{
CHAR *c, *endc;
size_t nchars, last_col, this_col;
last_col = 0;
nchars = l->l_line_len;
if (l->l_needs_sort) {
static CHAR *sorted;
static size_t count_size, i, sorted_size;
static int *count, save, tot;
/*
* Do an O(n) sort on l->l_line by column being careful to
* preserve the order of characters in the same column.
*/
if (l->l_lsize > sorted_size) {
sorted_size = l->l_lsize;
sorted = xreallocarray(sorted,
sorted_size, sizeof(CHAR));
}
if (l->l_max_col >= count_size) {
count_size = l->l_max_col + 1;
count = xreallocarray(count,
count_size, sizeof(int));
}
memset(count, 0, sizeof(*count) * (l->l_max_col + 1));
for (i = nchars, c = l->l_line; i-- > 0; c++)
count[c->c_column]++;
/*
* calculate running total (shifted down by 1) to use as
* indices into new line.
*/
for (tot = 0, i = 0; i <= l->l_max_col; i++) {
save = count[i];
count[i] = tot;
tot += save;
}
for (i = nchars, c = l->l_line; i-- > 0; c++)
sorted[count[c->c_column]++] = *c;
c = sorted;
} else
c = l->l_line;
while (nchars > 0) {
this_col = c->c_column;
endc = c;
do {
++endc;
} while (--nchars > 0 && this_col == endc->c_column);
/* if -b only print last character */
if (no_backspaces)
c = endc - 1;
if (this_col > last_col) {
size_t nspace = this_col - last_col;
if (compress_spaces && nspace > 1) {
size_t ntabs;
ntabs = ((last_col % 8) + nspace) / 8;
if (ntabs) {
nspace -= (ntabs * 8) - (last_col % 8);
while (ntabs-- > 0)
PUTC('\t');
}
}
while (nspace-- > 0)
PUTC(' ');
last_col = this_col;
}
last_col++;
for (;;) {
if (c->c_set != last_set) {
switch (c->c_set) {
case CS_NORMAL:
PUTC(SI);
break;
case CS_ALTERNATE:
PUTC(SO);
}
last_set = c->c_set;
}
PUTC(c->c_char);
if (++c >= endc)
break;
PUTC('\b');
}
}
}
/*
* Increment or decrement a line number, checking for overflow.
* Stop one below INT_MAX such that the adjust variable is safe.
*/
void
addto_lineno(int *lno, int offset)
{
if (offset > 0) {
if (*lno >= INT_MAX - offset)
errx(1, "too many lines");
} else {
if (*lno < INT_MIN - offset)
errx(1, "too many reverse line feeds");
}
*lno += offset;
}
#define NALLOC 64
static LINE *line_freelist;
LINE *
alloc_line(void)
{
LINE *l;
int i;
if (!line_freelist) {
l = xreallocarray(NULL, NALLOC, sizeof(LINE));
line_freelist = l;
for (i = 1; i < NALLOC; i++, l++)
l->l_next = l + 1;
l->l_next = NULL;
}
l = line_freelist;
line_freelist = l->l_next;
memset(l, 0, sizeof(LINE));
return (l);
}
void
free_line(LINE *l)
{
l->l_next = line_freelist;
line_freelist = l;
}
void *
xreallocarray(void *p, size_t n, size_t size)
{
if (!(p = reallocarray(p, n, size)))
err(1, "realloc failed");
return (p);
}
void
usage(void)
{
(void)fprintf(stderr, "usage: col [-bfhx] [-l num]\n");
exit(1);
}
void
dowarn(int line)
{
warnx("warning: can't back up %s",
line < 0 ? "past first line" : "-- line already flushed");
}