home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Arsenal Files 8
/
The Arsenal Files Collection #8 (Arsenal Computer) (1996).ISO
/
prg_casm
/
snip9611.zip
/
ISFOPEN.C
< prev
next >
Wrap
C/C++ Source or Header
|
1996-11-24
|
956b
|
47 lines
/* +++Date last modified: 02-Nov-1995 */
/*
** Find out if a FILE * is valid
**
** public domain demo by Bob Stout
*/
#include "dosfiles.h"
#ifdef __TURBOC__
#define STREAM_BUF _streams
#define FCNT FOPEN_MAX
#define FLAG flags
#elif defined(__WATCOMC__)
#define STREAM_BUF __iob
#define FCNT _NFILES
#define FLAG _flag
#else /* MSC, ZTC++ */
#define STREAM_BUF _iob
#define FCNT _NFILE
#define FLAG _flag
#endif
int isfopen(FILE *fp)
{
int i;
for (i = 0; i < FCNT; ++i)
{
if (0 != STREAM_BUF[i].FLAG && fp == &STREAM_BUF[i])
return True_;
}
return False_;
}
#ifdef TEST
main()
{
printf("stdout is%s valid\n", isfopen(stdout) ? "":" not");
printf("buffer #10 is%s valid\n", isfopen(&STREAM_BUF[9]) ? "":" not");
return 0;
}
#endif /*TEST */