ack/lang/basic/lib/file.c
2016-12-12 21:15:25 +01:00

131 lines
2.2 KiB
C

#include "bc_string.h"
#include <stdio.h>
#include "bc_io.h"
/* $Id$ */
Filedesc _fdtable[16];
/* BASIC file descriptor table */
/* Channel assignment:
-1 terminal IO
0 data file
1-15 user files
*/
int _chann = -1;
FILE *_chanrd = stdin;
FILE *_chanwr = stdout;
void _setchan(int index)
{
#ifdef DEBUG
printf("setchannel %d\n",index);
#endif
fflush(_chanwr);
if( index == -1)
{
_chann= -1;
_chanrd= stdin;
_chanwr= stdout;
return;
}
if( index<0 || index>15)
error(27);
_chann=index;
_chanrd= _chanwr= _fdtable[index].fd;
}
void _asschn(void)
{
#ifdef DEBUG
printf("_asschn %d\n",_chann);
#endif
if( _chann == -1) return;
#ifdef DEBUG
printf(" file %d\n", _fdtable[_chann].fd);
#endif
if( _chann<0 || _chann>15)
error(27);
if( _fdtable[_chann].fd== 0)
error(39);
if( feof( _fdtable[_chann].fd))
error(2);
}
void _clochn(int nr)
{
if( nr<1 || nr >15 || _fdtable[nr].fd==0) error(3);
fclose(_fdtable[nr].fd);
_fdtable[nr].fd=0; _fdtable[nr].fname=0;
}
void _opnchn(int reclen, String* fname, String* mode)
{
/* channel has been set */
FILE *f;
int m;
#ifdef DEBUG
printf("open %d %s %s \n",reclen,mode->strval,fname->strval);
#endif
/* check for opened/closed file */
if(_fdtable[_chann].fd)
error(30);
switch(*mode->strval)
{
case 'O':
case 'o':
if( (f=fopen(fname->strval,"w")) == NULL)
error(28);
m= OMODE;
break;
case 'I':
case 'i':
if( (f=fopen(fname->strval,"r")) == NULL)
error(28);
m= IMODE;
break;
case 'r':
case 'R':
if( (f=fopen(fname->strval,"a")) == NULL)
error(28);
m= RMODE;
break;
default:
printf("file mode %s\n",mode->strval);
error(29);
}
_chanwr= _chanrd= _fdtable[_chann].fd= f;
_fdtable[_chann].fname= fname->strval;
_fdtable[_chann].reclength= reclen;
_fdtable[_chann].mode= m;
#ifdef DEBUG
printf("file descr %d\n",f);
#endif
}
int _ioeof(int channel)
{
FILE *fd;
char c;
if( channel<0 || channel >15) error(3);
fd= _fdtable[channel].fd;
if( fd==0)
error(3);
c=fgetc(fd);
if( feof(_fdtable[channel].fd) ) return(-1);
ungetc(c,fd);
return(0);
}
void _close(void)
{
/* close all open files */
int i;
for(i=1;i<16;i++)
if( _fdtable[i].fd)
_clochn(i);
}