Upload

Digital Research

CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v101/klib/xopen.c

@@ -0,0 +1,73 @@
+/****************************************************************************/
+/*									    */
+/*			_ o p e n   F u n c t i o n			    */
+/*			---------------------------			    */
+/*									    */
+/*	Function "_open" is used to parse the CP/M fcb and open or create   */
+/*	the requested file.  Created files are deleted first, to avoid 	    */
+/*	directory problems.						    */
+/*									    */
+/*	Calling Sequence:						    */
+/*									    */
+/*		ret = _open(ch,filnam,bdosfunc);			    */
+/*									    */
+/*	Where:								    */
+/*		ch	Is a vacant channel number			    */
+/*		filnam	Is a null-terminated CP/M filename		    */
+/*		bdosfunc Is the desired BDOS function to perform	    */
+/*									    */
+/*	This routine may also be used to delete files as well.		    */
+/*									    */
+/****************************************************************************/
+#include "stdio.h"
+#include "cpm.h"
+WORD	_open(ch,filnam,bdosfunc)		/****************************/
+						/*			    */
+	WORD	ch;				/* Channel number	    */
+REG	BYTE	*filnam;			/* -> filename		    */
+	WORD	bdosfunc;			/* BDOS Function	    */
+{						/****************************/
+EXTERN	FILE	*_getc();			/* fd -> fp xlate routine   */
+REG	FILE	*fp;				/* -> ccb area		    */
+REG	struct xfcb	*fcbp;			/* -> FCB area in ccb	    */
+REG	BYTE	*p;				/* Temp character pointer   */
+REG	WORD	i;				/* Character index	    */
+						/****************************/
+	fp = _getc(ch);				/* Fetch ccb pointer	    */
+	fcbp = &(fp ->fcb);			/* Fetch fcb pointer	    */
+						/****************************/
+	if(*(filnam+1) == ':')			/* Drive ID present?	    */
+	{					/* 	If here, yes	    */
+		fcbp->drive = toupper(*filnam)	/* Load drive ID	    */
+			      - 'A' + 1;	/* 1 for a:, 2 for b:, ...  */
+		filnam += 2;			/* Bump past ':'	    */
+	}					/****************************/
+						/*			    */
+	i = 0;					/* index		    */
+						/****************************/
+	while (*filnam > ' ' && i < 8 &&	/* 			    */
+		*filnam != '.')			/* Terminate on ext.	    */
+	{					/*			    */
+		fcbp -> fname[i++] = 		/* Load next character	    */
+			toupper(*filnam);	/* 			    */
+		filnam++;			/* Increment		    */
+	}					/*			    */
+						/****************************/
+	if (*filnam == '.')			/* Extension specified?	    */
+	{					/* Yes			    */
+	  filnam++;				/* Bump past '.'	    */
+	  i = 0;				/* set index to 0	    */
+	  while(*filnam > ' ' && i < 3)		/* copy			    */
+	  {					/*			    */
+		fcbp -> ftype[i++] = 		/*			    */
+			toupper(*filnam);	/*	file type	    */
+		filnam++;			/*			    */
+	  }					/*			    */
+	}					/****************************/
+						/*			    */
+	if(bdosfunc == CREATE)			/* Creating file?	    */
+		__BDOS(DELETE,fcbp);		/* Yes, delete it first	    */
+						/****************************/
+	i = __BDOS(bdosfunc,fcbp);		/* Do requested operation   */
+	return((i<=3) ? SUCCESS : FAILURE);	/* Binary return code	    */
+}						/****************************/