Files
Sepp J Morris 31738079c4 Upload
Digital Research
2020-11-06 18:50:37 +01:00

65 lines
2.3 KiB
C

/****************************************************************************
*
* C F I L E O P E N R O U T I N E
* -------------------------------------
*
* The "open" routine opens a "C" file and returns a file id.
*
* Calling Sequence:
*
* fid = open(fname,mode,type);
*
* Where:
*
* fname is the address of a null terminated file name.
* mode is the open mode:
*
* 0 => READ access only
* 1 => WRITE access only
* 2 => Both READ and WRITE
* type is 0 for ASCII files, 1 for BINARY
*
*
*****************************************************************************/
#include "stdio.h" /* Include Whitesmith's */
#include "cpm.h" /* + CP/M */
EXTERN BYTE __tname[]; /* -> CON: */
EXTERN BYTE __lname[]; /* -> LST: */
WORD open (fname,mode,xtype) /****************************/
BYTE *fname; /* -> File name */
WORD mode; /* Open mode */
WORD xtype; /* File type */
{ /****************************/
REG WORD ich; /* Channel number for open */
REG FILE *ch; /* -> CCB for channel */
EXTERN FILE *_getc(); /* fd to fp converter */
/* */
if((ich = igetc()) < 0) /* Allocate a channel */
return (FAILURE); /* Can't */
/* */
__chinit(ich); /* Clear out channel's ccb */
ch = _getc(ich); /* Get address of ccb */
/* */
if(mode == READ) /* If read only, */
ch -> flags |= ISREAD; /* set READONLY bit*/
if(xtype == 0) /* Is ASCII file? */
ch -> flags |= ISASCII; /* Yes, mark it */
/* */
if(_strcmp(fname,__tname) == 0) /* if a terminal */
{ /* */
ch->flags |= ISTTY|OPENED; /* mark as tty */
return(ich); /* Return file descriptor */
} /****************************/
else if(_strcmp(fname,__lname) == 0) /* List device? */
{ /* */
ch->flags |= ISLPT|OPENED; /* Mark as printer */
return(ich); /* Return file descriptor */
} /* */
/****************************/
if(_open(ich,fname,OPEN) != 0) /* Use POS SVC interface */
return(FAILURE); /* If return <> 0, NFG. */
/* Else: */
ch -> flags |= OPENED; /* Set OPEN bit */
return(ich); /* Return Channel # */
} /****************************/