NetBSD/bin/ed/buf.c

220 lines
5.2 KiB
C

/* buf.c: This file contains the scratch-file buffer rountines for the
ed line editor. */
/*-
* Copyright (c) 1992 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rodney Ruddock of the University of Guelph.
*
* 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.
*/
#ifndef lint
static char sccsid[] = "@(#)buf.c 5.5 (Berkeley) 3/28/93";
#endif /* not lint */
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include <unistd.h>
#include "ed.h"
extern char errmsg[];
extern line_t line0;
FILE *sfp; /* scratch file pointer */
off_t sfseek; /* scratch file position */
int seek_write; /* seek before writing */
/* gettxt: get a line of text from the scratch file; return pointer
to the text */
char *
gettxt(lp)
line_t *lp;
{
static char txtbuf[MAXLINE];
int len, ct;
if (lp == &line0)
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) {
sprintf(errmsg, "cannot seek temp file");
return (char *) ERR;
}
}
len = lp->len & ~ACTV;
if ((ct = fread(txtbuf, sizeof(char), len, sfp)) < 0 || ct != len) {
sprintf(errmsg, "cannot read temp file");
return (char *) ERR;
}
sfseek += len; /* update file position */
txtbuf[len] = '\0';
return txtbuf;
}
extern long curln;
extern long lastln;
/* puttxt: 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 *
puttxt(cs)
char *cs;
{
line_t *lp;
int len, ct;
char *s;
if ((lp = (line_t *) malloc(sizeof(line_t))) == NULL) {
sprintf(errmsg, "out of memory");
return (char *) ERR;
}
/* assert: cs is '\n' terminated */
for (s = cs; *s != '\n'; s++)
;
len = (s - cs) & ~ACTV;
/* out of position */
if (seek_write) {
if (fseek(sfp, 0L, SEEK_END) < 0) {
sprintf(errmsg, "cannot seek temp file");
return (char *) ERR;
}
sfseek = ftell(sfp);
seek_write = 0;
}
/* assert: spl1() */
if ((ct = fwrite(cs, sizeof(char), len, sfp)) < 0 || ct != len) {
sfseek = -1;
sprintf(errmsg, "cannot write temp file");
return (char *) ERR;
}
lp->len = len;
lp->seek = sfseek;
lpqueue(lp);
sfseek += len; /* update file position */
return (*++s == '\0') ? NULL : s;
}
/* lpqueue: add a line node in the editor buffer after the current line */
void
lpqueue(lp)
line_t *lp;
{
line_t *cp;
cp = getptr(curln); /* this getptr last! */
insqueue(lp, cp);
lastln++;
curln++;
}
extern int mutex;
extern int sigflags;
/* getptr: return pointer to a line node in the editor buffer */
line_t *
getptr(n)
long n;
{
static line_t *lp = &line0;
static long on = 0;
spl1();
if (n > on)
if (n <= (on + lastln) >> 1)
for (; on < n; on++)
lp = lp->next;
else {
lp = line0.prev;
for (on = lastln; on > n; on--)
lp = lp->prev;
}
else
if (n >= on >> 1)
for (; on > n; on--)
lp = lp->prev;
else {
lp = &line0;
for (on = 0; on < n; on++)
lp = lp->next;
}
spl0();
return lp;
}
char sfn[15] = ""; /* scratch file name */
/* sbopen: open scratch file */
sbopen()
{
strcpy(sfn, "/tmp/ed.XXXXXX");
if (mktemp(sfn) == NULL || (sfp = fopen(sfn, "w+")) == NULL) {
sprintf(errmsg, "cannot open temp file");
return ERR;
}
return 0;
}
/* sbclose: close scratch file */
sbclose()
{
if (sfp) {
fclose(sfp);
sfp = NULL;
unlink(sfn);
}
sfseek = seek_write = 0;
}
/* quit: remove scratch file and exit */
void
quit(n)
int n;
{
if (sfp) {
unlink(sfn);
fclose(sfp);
}
exit(n);
}