_fopen.c

#ifndef mini__fopen_c
#define mini__fopen_c

#include "include/filemodes.h"
int volatile open( const char *s, int flags, ... );

//+header stdio.h
//+depends open fileno close
//+needs lseek.h
//+doc modes implemented: r, r+, w, w+, a, a+
//+def
FILE *_fopen(int fd, const char* filename, const char* mode, FILE *f){
		int imode;

		switch (mode[0]){
				case 'r': imode = O_RDONLY;
									break;
				case 'w': imode = O_WRONLY | O_TRUNC | O_CREAT;
									break;
				case 'a': imode = O_APPEND | O_RDWR; // somehow only "a+" works. Not sure, why.
									break;
				default: return((FILE*)0); // hopefully a fd cannot be 0.? By reading the manual, 
								 // I conclude only stdin has the fildes 0. So It MIGHT be ok.
								  // Anyways, if someone's trying to open stdin via fopen and is wondering, what's going on..
								 // Here's the answer. But, regarding the bsd manuals, one shouldn't open stdin with fopen at all. so..
		}

		for ( int a=1; (mode[a] != 0) && ( a<6 ); a++ ){
 				if ( mode[a] == '+' ){ 
						imode = ( ( imode | O_RDWR ) & ~( O_WRONLY | O_RDONLY) );
				} else {
#if 0
				//printf("XXX: %c", mode[a]);
						switch (mode[0]){
								case 'r': //imode = O_RDONLY;
										break;
								case 'w': if ( mode[a] == 'x' )
															imode = imode & ( ~(O_CREAT | O_TRUNC) );
													break;
								case 'a': //imode = O_APPEND | O_RDWR; 
													break;
						}
#endif
				}
		}

		if ( f == 0 ){
				int a;
				if ( mlgl->pstream >= mini_FOPEN_MAX){ // Too many opened streams. Look for an empty storage location
						for ( a=3; mlgl->stream[a]>=0; a++ )
								if ( a >= mini_FOPEN_MAX ) // 
										return(0);
				} else {
						a = mlgl->pstream;
						mlgl->pstream++;
				}

				//printf("a: %d\n",a);
				f = &mlgl->stream[a];
		} else { // freopen - error handling?
				close(fileno(f));
		}
		if ( filename != 0 )
			*f	 =  open( filename, imode, 0666 );
		else 
			*f = fd;

		//if ( *f == -1 )
		if ( *f < 0 )
				return(0);

		return ( f ); // 
}




#endif