cpm commands

WEGA/contrib/cpm/cpm3/extent.c

@@ -0,0 +1,68 @@
+/*	extent.c	1.7	83/05/13	*/
+
+#include <stdio.h>
+#include "cpmio.h"
+#include "cpmfio.h"
+
+/*
+ * Allocate a new extent to the file pointed to by curext,
+ * or, if curext < 0, return the index of the first free
+ * directory slot.
+ * Return a negative pointer if no directory space, otherwise
+ * the index to the new extent.
+ */
+
+creext(curext)
+	int curext;
+{
+
+	int i, j;
+
+	for (i=0; i < maxdir; i++)
+		if ((dirbuf + i)->status == (char) 0xe5) 
+			break;
+	if (i == maxdir) 
+		return (EOF);
+	if (curext >= 0) 
+		*(dirbuf+i) = *(dirbuf+curext);
+	
+	/* clear all file pointers */
+	for (j=0; j<16; j++)
+		(dirbuf+i)->pointers[j] = '\0';
+
+#ifdef DEBUG
+	printf("extent allmcated: %d (old: %d)\n", i, curext);
+	printf("extent data: 0x%x, name: %s\n", (dirbuf+i)->status,
+			(dirbuf+i)->name);
+#endif
+	return(i);
+}
+
+
+/*
+ * Find next extent of the file pointed to by file pointer 'current',
+ * return the new extent's index if founf, otherwise NULL.
+ */
+
+getnext(cur)
+	C_FILE	*cur;
+{
+
+	int	ind;
+
+	cur->c_extno++;
+	for (ind = 0; ind < maxdir; ind++) 
+		if ((strncmp(cur->c_dirp->name,(dirbuf+ind)->name,8)==0) &&
+		    (strncmp((dirbuf+ind)->ext, cur->c_dirp->ext,3)==0) &&
+		    ((dirbuf+ind)->extno == cur->c_extno)) {
+			cur->c_ext=ind;
+			cur->c_seccnt = 0xff & (int)(dirbuf+ind)->blkcnt;
+			cur->c_dirp = dirbuf + ind;
+			cur->c_blk = 0;
+#ifdef DEBUG
+			printf("getnext: dir. index: %d\n",ind); 
+#endif
+			return (ind);
+		}
+	return (NULL);
+}