sch@oce.nl.UUCP (Jakob Schripsema) (01/01/88)
I'm using MicroEmacs (3.7, 3.8, 3.9) on an IBM compatible in combination
with Sun's PC-NFS. MicroEmacs has been compiled with MSC 4.00.
Writing a file from Emacs to a network disk is a disaster, it takes
minutes to write it out. After some digging I discovered why :
1. PC-NFS has a lousy performance when used with unbuffered IO
(Try redirecting screen output to a file on the virtual disk)
2. When fputc encounters a \n the output buffer is flushed. This
is fine for output to the screen, but when writing to a file
it has no use. I don't know if libraries from other compilers
act the same.
The solution is simple : output files should be opened in binary mode.
This requires minimal changes to ffwopen and ffputline (both in fileio.c).
JaKob Schripsema (sch@oce)
Oce Nederland B.V.
PO box 101
5900MA Venlo
The Netherlands
=====================================================
This note does not necessarily represent the position
of Oce-Nederland B.V. Therefore no liability or
responsibility for whatever will be accepted.
=====================================================
-------fileio.c--from 3.9----cut here------
/*
* The routines in this file read and write ASCII files from the disk. All of
* the knowledge about files are here.
*/
#include <stdio.h>
#include "estruct.h"
#include "edef.h"
FILE *ffp; /* File pointer, all functions. */
int eofflag; /* end-of-file flag */
/*
* Open a file for reading.
*/
ffropen(fn)
char *fn;
{
if ((ffp=fopen(fn, "r")) == NULL)
return (FIOFNF);
eofflag = FALSE;
return (FIOSUC);
}
/*
* Open a file for writing. Return TRUE if all is well, and FALSE on error
* (cannot create).
*/
ffwopen(fn)
char *fn;
{
#if VMS
register int fd;
if ((fd=creat(fn, 0666, "rfm=var", "rat=cr")) < 0
|| (ffp=fdopen(fd, "w")) == NULL) {
#else
#if MSDOS
if ((ffp=fopen(fn, "wb")) == NULL) {
#else
if ((ffp=fopen(fn, "w")) == NULL) {
#endif
#endif
mlwrite("Cannot open file for writing");
return (FIOERR);
}
return (FIOSUC);
}
/*
* Close a file. Should look at the status in all systems.
*/
ffclose()
{
/* free this since we do not need it anymore */
if (fline) {
free(fline);
fline = NULL;
}
#if MSDOS & CTRLZ
fputc(26, ffp); /* add a ^Z at the end of the file */
#endif
#if V7 | USG | BSD | (MSDOS & (LATTICE | MSC | TURBO)) | (ST520 & MWC)
if (fclose(ffp) != FALSE) {
mlwrite("Error closing file");
return(FIOERR);
}
return(FIOSUC);
#else
fclose(ffp);
return (FIOSUC);
#endif
}
/*
* Write a line to the already opened file. The "buf" points to the buffer,
* and the "nbuf" is its length, less the free newline. Return the status.
* Check only at the newline.
*/
ffputline(buf, nbuf)
char buf[];
{
register int i;
#if CRYPT
char c; /* character to translate */
if (cryptflag) {
for (i = 0; i < nbuf; ++i) {
c = buf[i] & 0xff;
crypt(&c, 1);
fputc(c, ffp);
}
} else
for (i = 0; i < nbuf; ++i)
fputc(buf[i]&0xFF, ffp);
#else
for (i = 0; i < nbuf; ++i)
fputc(buf[i]&0xFF, ffp);
#endif
#if (ST520 & ADDCR) | MSDOS
fputc('\r', ffp);
#endif
fputc('\n', ffp);
if (ferror(ffp)) {
mlwrite("Write I/O error");
return (FIOERR);
}
return (FIOSUC);
}
/*
* Read a line from a file, and store the bytes in the supplied buffer. The
* "nbuf" is the length of the buffer. Complain about long lines and lines
* at the end of the file that don't have a newline present. Check for I/O
* errors too. Return status.
*/
ffgetline()
{
register int c; /* current character read */
register int i; /* current index into fline */
register char *tmpline; /* temp storage for expanding line */
/* if we are at the end...return it */
if (eofflag)
return(FIOEOF);
/* dump fline if it ended up too big */
if (flen > NSTRING) {
free(fline);
fline = NULL;
}
/* if we don't have an fline, allocate one */
if (fline == NULL)
if ((fline = malloc(flen = NSTRING)) == NULL)
return(FIOMEM);
/* read the line in */
i = 0;
while ((c = fgetc(ffp)) != EOF && c != '\n') {
fline[i++] = c;
/* if it's longer, get more room */
if (i >= flen) {
if ((tmpline = malloc(flen+NSTRING)) == NULL)
return(FIOMEM);
strncpy(tmpline, fline, flen);
flen += NSTRING;
free(fline);
fline = tmpline;
}
}
#if ST520
if(fline[i-1] == '\r')
i--;
#endif
/* test for any errors that may have occured */
if (c == EOF) {
if (ferror(ffp)) {
mlwrite("File read error");
return(FIOERR);
}
if (i != 0)
eofflag = TRUE;
else
return(FIOEOF);
}
/* terminate and decrypt the string */
fline[i] = 0;
#if CRYPT
if (cryptflag)
crypt(fline, strlen(fline));
#endif
return(FIOSUC);
}
int fexist(fname) /* does <fname> exist on disk? */
char *fname; /* file to check for existance */
{
FILE *fp;
/* try to open the file for reading */
fp = fopen(fname, "r");
/* if it fails, just return false! */
if (fp == NULL)
return(FALSE);
/* otherwise, close it and report true */
fclose(fp);
return(TRUE);
}
#if AZTEC & MSDOS
#undef fgetc
/* a1getc: Get an ascii char from the file input stream
but DO NOT strip the high bit
*/
int a1getc(fp)
FILE *fp;
{
int c; /* translated character */
c = getc(fp); /* get the character */
/* if its a <LF> char, throw it out */
while (c == 10)
c = getc(fp);
/* if its a <RETURN> char, change it to a LF */
if (c == '\r')
c = '\n';
/* if its a ^Z, its an EOF */
if (c == 26)
c = EOF;
return(c);
}
#endif