minix/bin/ed/buf.c

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2012-03-10 00:17:50 +01:00
/* $NetBSD: buf.c,v 1.26 2006/03/17 14:37:14 rumble Exp $ */
/* buf.c: This file contains the scratch-file buffer routines for the
ed line editor. */
/*-
* Copyright (c) 1993 Andrew Moore, Talke Studio.
* All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
#ifndef lint
#if 0
static char *rcsid = "@(#)buf.c,v 1.4 1994/02/01 00:34:35 alm Exp";
#else
__RCSID("$NetBSD: buf.c,v 1.26 2006/03/17 14:37:14 rumble Exp $");
#endif
#endif /* not lint */
#include <sys/file.h>
#include <sys/stat.h>
#include <paths.h>
#include <stdio.h>
#include <err.h>
#include "ed.h"
FILE *sfp; /* scratch file pointer */
off_t sfseek; /* scratch file position */
int seek_write; /* seek before writing */
line_t buffer_head; /* incore buffer */
/* get_sbuf_line: get a line of text from the scratch file; return pointer
to the text */
char *
get_sbuf_line(line_t *lp)
{
static char *sfbuf = NULL; /* buffer */
static int sfbufsz = 0; /* buffer size */
int len, ct;
if (lp == &buffer_head)
return NULL;
seek_write = 1; /* force seek on write */
/* out of position */
if (sfseek != lp->seek) {
sfseek = lp->seek;
if (fseek(sfp, sfseek, SEEK_SET) < 0) {
fprintf(stderr, "%s\n", strerror(errno));
sprintf(errmsg, "cannot seek temp file");
return NULL;
}
}
len = lp->len;
REALLOC(sfbuf, sfbufsz, len + 1, NULL);
if ((ct = fread(sfbuf, sizeof(char), len, sfp)) < 0 || ct != len) {
fprintf(stderr, "%s\n", strerror(errno));
sprintf(errmsg, "cannot read temp file");
return NULL;
}
sfseek += len; /* update file position */
sfbuf[len] = '\0';
return sfbuf;
}
/* put_sbuf_line: write a line of text to the scratch file and add a line node
to the editor buffer; return a pointer to the end of the text */
char *
put_sbuf_line(char *cs)
{
line_t *lp;
int len, ct;
char *s;
if ((lp = (line_t *) malloc(sizeof(line_t))) == NULL) {
fprintf(stderr, "%s\n", strerror(errno));
sprintf(errmsg, "out of memory");
return NULL;
}
/* assert: cs is '\n' terminated */
for (s = cs; *s != '\n'; s++)
;
if (s - cs >= LINECHARS) {
sprintf(errmsg, "line too long");
free(lp);
return NULL;
}
len = s - cs;
/* out of position */
if (seek_write) {
if (fseek(sfp, 0L, SEEK_END) < 0) {
fprintf(stderr, "%s\n", strerror(errno));
sprintf(errmsg, "cannot seek temp file");
free(lp);
return NULL;
}
sfseek = ftell(sfp);
seek_write = 0;
}
/* assert: SPL1() */
if ((ct = fwrite(cs, sizeof(char), len, sfp)) < 0 || ct != len) {
sfseek = -1;
fprintf(stderr, "%s\n", strerror(errno));
sprintf(errmsg, "cannot write temp file");
free(lp);
return NULL;
}
lp->len = len;
lp->seek = sfseek;
add_line_node(lp);
sfseek += len; /* update file position */
return ++s;
}
/* add_line_node: add a line node in the editor buffer after the current line */
void
add_line_node(line_t *lp)
{
line_t *cp;
cp = get_addressed_line_node(current_addr); /* this get_addressed_line_node last! */
INSQUE(lp, cp);
addr_last++;
current_addr++;
}
/* get_line_node_addr: return line number of pointer */
long
get_line_node_addr(line_t *lp)
{
line_t *cp = &buffer_head;
long n = 0;
while (cp != lp && (cp = cp->q_forw) != &buffer_head)
n++;
if (n && cp == &buffer_head) {
sprintf(errmsg, "invalid address");
return ERR;
}
return n;
}
/* get_addressed_line_node: return pointer to a line node in the editor buffer */
line_t *
get_addressed_line_node(long n)
{
static line_t *lp = &buffer_head;
static long on = 0;
SPL1();
if (n > on) {
if (n <= (on + addr_last) >> 1) {
for (; on < n; on++)
lp = lp->q_forw;
} else {
lp = buffer_head.q_back;
for (on = addr_last; on > n; on--)
lp = lp->q_back;
}
} else {
if (n >= on >> 1) {
for (; on > n; on--)
lp = lp->q_back;
} else {
lp = &buffer_head;
for (on = 0; on < n; on++)
lp = lp->q_forw;
}
}
SPL0();
return lp;
}
char *sfn = NULL; /* scratch file name */
/* open_sbuf: open scratch file */
int
open_sbuf(void)
{
int u, fd;
const char *tmp;
size_t s;
isbinary = newline_added = 0;
fd = -1;
u = umask(077);
if ((tmp = getenv("TMPDIR")) == NULL)
tmp = _PATH_TMP;
if ((s = strlen(tmp)) == 0 || tmp[s - 1] == '/')
(void)asprintf(&sfn, "%sed.XXXXXX", tmp);
else
(void)asprintf(&sfn, "%s/ed.XXXXXX", tmp);
if (sfn == NULL) {
warn(NULL);
sprintf(errmsg, "could not allocate memory");
umask(u);
return ERR;
}
if ((fd = mkstemp(sfn)) == -1 || (sfp = fdopen(fd, "w+")) == NULL) {
if (fd != -1)
close(fd);
warn("%s", sfn);
sprintf(errmsg, "cannot open temp file");
umask(u);
return ERR;
}
umask(u);
return 0;
}
/* close_sbuf: close scratch file */
int
close_sbuf(void)
{
if (sfp) {
if (fclose(sfp) < 0) {
fprintf(stderr, "%s: %s\n", sfn, strerror(errno));
sprintf(errmsg, "cannot close temp file");
return ERR;
}
sfp = NULL;
if (sfn) {
unlink(sfn);
free(sfn);
sfn = NULL;
}
}
sfseek = seek_write = 0;
return 0;
}
/* quit: remove_lines scratch file and exit */
void
quit(int n)
{
if (sfp) {
fclose(sfp);
if (sfn) {
unlink(sfn);
free(sfn);
sfn = NULL;
}
}
exit(n);
/* NOTREACHED */
}
unsigned char ctab[256]; /* character translation table */
/* init_buffers: open scratch buffer; initialize line queue */
void
init_buffers(void)
{
int i = 0;
/* Read stdin one character at a time to avoid i/o contention
with shell escapes invoked by nonterminal input, e.g.,
ed - <<EOF
!cat
hello, world
EOF */
setbuffer(stdin, stdinbuf, 1);
if (open_sbuf() < 0)
quit(2);
REQUE(&buffer_head, &buffer_head);
for (i = 0; i < 256; i++)
ctab[i] = i;
}
/* translit_text: translate characters in a string */
char *
translit_text(char *s, int len, int from, int to)
{
static int i = 0;
unsigned char *us;
ctab[i] = i; /* restore table to initial state */
ctab[i = from] = to;
for (us = (unsigned char *) s; len-- > 0; us++)
*us = ctab[*us];
return s;
}