Category : C Source Code
Archive   : ANCTEST.ZIP
Filename : TESTANSI.C

/*
* Ansitest -- test whether ANSI.SYS is installed
*
* Use --- just run the program ANSI.EXE. It will tell you whether
* or not ANSI.SYS has been loaded. It sets the MSDOS ERRORLEVEL
* variable to 0 if ANSI.SYS is active, 1 if not, so if used in a
* batch file like
*
* ECHO OFF
* ECHO This is a batch file.
* PATH C:\;A:\;B:\
* TESTANSI
* IF errorlevel 1 goto NOANSI
* ;
* REM if TESTANSI set the errorlevel to 1, this command gets skipped
* SET PROMPT=$e[s$e[1;68H$e[7m $t$h$h$h$e[0m$e[u$h$h$n$g
* ;
* :NOANSI
* SET PATH=C:\;A:\;B:\
*
* the batch file can know whether ANSI.SYS is part of the
* environment. The PROMPT is an ANSI-driven prompt that creates an
* on-screen clock; since it requires ANSI.SYS to be loaded in order
* to work, the batch file can skip over that command.
*
* Entire work (C) Copyright 1988, Loren E Heal.
* Private hobbyists feel free to copy and distribute this material,
* as long as NO money changes hands. This is "freeware", but not
* Public Domain. Commercial or government users must contact the
* author for licensing.
* Loren E. Heal
* 607 W. Healey St, #5
* Champaign, IL 61820
* EMAIL: Phoeni-Xanadu BBS, 217-
* July, 1988
*
*/
/*
* Source Notes
*
* The program operates by sending to the STDOUT device the escape
* sequence that ANSI.SYS (hereon "ANSI" or "the driver") recognizes
* as a Device Status Request, or DSR. The driver, if present, will
* place an RCP, Return Cursor Position, sequence onto the input
* stream. If ANSI (or a clone) is not active, then the DSR string
* will have been printed to the screen and not swallowed by the
* driver.
*
* I used an assembly language routine, rather than the C library
* routines, for compactness. The program might work as well using
* a combination of kbhit(), getch(), and printf(), but the smaller
* .ASM routine (included as a comment below the source) was more
* fun to write.
*
*/
#include

#define NOT_OK (1)
#define OK (0)
#define EMPTY (0)
#define GETIN (0xff)
#define US unsigned short
#define UL unsigned long
#define ESC ('\x1b')
#define DSR ("\x1b[6n")
#define SCP ("\x1b[s")
#define RCP ("\x1b[u")
#define RIGHTS ("(C) 1988 Loren E. Heal\n\r")
static char *goodmsg = ("\x1b[1mANSI\x1b[0m active\n");
static char *badmsg = ("\b\b\b\b\bANSI inactive\n");

void main(),exit();
int print();
US dircon();
void
main()
{
int c;

print(RIGHTS); /* send Copyright notice */
print(DSR); /* send ANSI Device Status Request */
c = (int) dircon(GETIN); /* check next character (kbhit() */
/* would be followed by getch()) */
while(dircon(GETIN)); /* swallow RCP string */
if(c == ESC) /* if RCP received */
{
print(goodmsg); /* signal device installed */
c = OK; /* and set exit code */
}
else /* else */
{
print(badmsg); /* erase trash and give result */
c = NOT_OK; /* set exit code */
}
exit(c);
}

/* No argument or environment checks, so these routines are put
here to save a few bytes -- MSC 3.0 */
void _setenvp() { }
void _setargv() { }
void _nullcheck() { }

/*
* PRINT: Print a string to the console via DIRCON
* -- Pass a string pointer
* -- returns the number of characters printed
*/
int
print(str)
char *str;
{
int i;
for(i=0; str[i]; dircon(str[i++]))
if(str[i] == '\n') dircon('\r');
return(i-1);
}
/*
* DIRCON : Direct console I/O via MSDOS int21h, Fct 6
*
* -- if dl is a character, it will be printed to the console
* -- if dl is 0xff, function returns either 0 or
* the character. The following is what the assembly
* code looks like
*
* _dircon PROC NEAR
* PUSH BP
* MOV BP,SP
* mov DL,[BP+4]
* mov AH,6
* int 21h
* jnz D1 ; if no char waiting, zflag is set
* mov AL,0 ; so load a 0 into AL for return
* d1: ; endif
* mov AH,0 ; load AH with 0
* mov SP,BP ; and return either 0 or the char in AX
* POP BP
* RET
* _dircon ENDP
*/