add test for opening character devices (all pass on DOS 5,6, NT VDM, @:dev fail currently on FD kernel)

tests/opendev/build.bat

@@ -0,0 +1,2 @@
+@ECHO OFF
+wcl -e3-we-wx-zq-os-s-zp1-mt-bt=DOS opendev.c

tests/opendev/opendev.c

@@ -0,0 +1,134 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <dos.h>
+
+#define MAX_PATH 256
+
+#define	OPEN_HANDLE 0x3d
+#define	CLOSE_HANDLE 0x3e
+
+#define FAILURE 0
+#define SUCCESS (!FAILURE)
+
+
+/* opens device, 
+   prepends device name with specified drive letter, 
+   returns handle to open device or -1 on error 
+ */
+int open_dev(const char drive_letter, const char *device_name)
+{
+	union REGS regs;
+	struct SREGS sregs;
+	char buffer[MAX_PATH];
+
+	sprintf(buffer, "%c:%s", drive_letter, device_name);
+	
+	printf("Opening %s\n", buffer);
+
+	regs.h.ah = OPEN_HANDLE;
+	regs.h.al = 0;
+	regs.x.dx = FP_OFF((void far *)buffer);
+	sregs.ds = FP_SEG((void far *)buffer);
+	intdosx(&regs, &regs, &sregs);
+	if (regs.x.cflag)
+		return -1;
+	return regs.x.ax;
+}
+
+/* close device using file descriptor returned from open_dev
+ */
+void close_dev(int fd)
+{
+	union REGS regs;
+
+	regs.h.ah = CLOSE_HANDLE;
+	regs.x.bx = fd;
+	intdos(&regs, &regs);
+}
+
+int test_device(const char drive_letter, const char *device_name, int should_fail)
+{
+	int fd;
+	fd = open_dev(drive_letter, device_name);
+	if (fd != -1) 
+		close_dev(fd);
+
+	if ( ((fd == -1) && should_fail) || ((fd != -1) && !should_fail) )
+	{
+		printf("SUCCESS - ");
+		if (should_fail)
+			printf("open failed\n");
+		else
+			printf("open succeeded\n");
+		return SUCCESS;
+	}
+	else 
+	{
+		printf("FAILURE - ");
+		if (should_fail)
+			printf("open succeeded\n");
+		else
+			printf("open failed\n");
+		return FAILURE;
+	}
+}
+
+int do_tests_on(const char *device_name)
+{
+	int status = SUCCESS;
+	char buffer[MAX_PATH];
+	const char current_drive = (char)('A'+_getdrive()-1);
+
+	sprintf(buffer, "%s", device_name);
+	if (!test_device('@', buffer,0)) status = FAILURE;
+	if (!test_device(current_drive, buffer,0)) status = FAILURE;
+
+	/* DIREXIST should exist in the current directory */
+	sprintf(buffer, "DIREXIST\\%s", device_name);
+	if (!test_device('@', buffer,1)) status = FAILURE;            /* drive does not exist, should fail */
+	if (!test_device(current_drive, buffer,0)) status = FAILURE;  /* valid drive, should succeed       */
+
+	sprintf(buffer, "BAD_PATH\\%s", device_name);
+	if (!test_device('@', buffer,1)) status = FAILURE;
+	if (!test_device(current_drive, buffer,1)) status = FAILURE;
+
+	sprintf(buffer, "\\%s", device_name);
+	if (!test_device('@', buffer,1)) status = FAILURE;             /* drive does not exist, should fail */
+	if (!test_device(current_drive, buffer,0)) status = FAILURE;   /* valid drive, should succeed       */
+
+	sprintf(buffer, "\\BAD_PATH\\%s", device_name);
+	if (!test_device('@', buffer,1)) status = FAILURE;
+	if (!test_device(current_drive, buffer,1)) status = FAILURE;
+
+	sprintf(buffer, "\\DEV\\%s", device_name);
+	if (!test_device('@', buffer,0)) status = FAILURE;
+	if (!test_device(current_drive, buffer,0)) status = FAILURE;
+
+	return status;
+}
+
+int test_CON()
+{
+	return do_tests_on("CON");
+}
+
+int test_NUL()
+{
+	return do_tests_on("NUL");
+}
+
+int test_COM()
+{
+	return do_tests_on("COM1");
+}
+
+int main(int argc, char *argv[]) 
+{
+	int error_code = 0;
+	if (!test_CON()) error_code |= 0x01;
+	if (!test_NUL()) error_code |= 0x02;
+	if (!test_COM()) error_code |= 0x04;
+
+	return error_code;
+}