fdopen.c

Go to the documentation of this file.

/*
 * fdopen - convert a (UNIX) file descriptor into a FILE pointer
 */
/* $Header: /opt/proj/minix/cvsroot/src/lib/other/fdopen.c,v 1.2 2005/09/06 10:15:57 beng Exp $ */

#include        <stdlib.h>
#include        "../stdio/loc_incl.h"
#include        <stdio.h>
#include        <sys/stat.h>

FILE *
fdopen(fd, mode)
int fd;
_CONST char *mode;
{
        register int i;
        struct stat st;
        FILE *stream;
        int flags = 0;

        if (fd < 0) return (FILE *)NULL;
        for (i = 0; __iotab[i] != 0 ; i++) 
                if (i >= FOPEN_MAX-1)
                        return (FILE *)NULL;

        switch(*mode++) {
        case 'r':
                flags |= _IOREAD | _IOREADING;
                break;
        case 'a':
                flags |= _IOAPPEND;
        case 'w':
                flags |= _IOWRITE | _IOWRITING;
                break;
        default:
                return (FILE *)NULL;
        }
        while(*mode) {
                switch(*mode++) {
                case 'b':
                        continue;
                case '+':
                        flags |= _IOREAD | _IOWRITE;
                        continue;
                /* The sequence may be followed by aditional characters */
                default:
                        break;
                }
                break;
        }

        if ( fstat( fd, &st ) < 0 ) {
                return (FILE *)NULL;
        }
        
        if ( st.st_mode & S_IFIFO ) {
                flags |= _IOFIFO;
        }
        
        if ((stream = (FILE *) malloc(sizeof(FILE))) == NULL) {
                return (FILE *)NULL;
        }

        if ((flags & _IOREAD) && (flags & _IOWRITE))
                flags &= ~(_IOREADING | _IOWRITING);

        stream->_count = 0;
        stream->_fd = fd;
        stream->_flags = flags;
        stream->_buf = NULL;
        __iotab[i] = stream;
        return stream;
}

---