/* * fopen.c - open a stream */ /* $Header$ */ #include #include #include #include "loc_incl.h" #define PMODE 0666 int open(const char *path, int flags, int mode); int close(int d); FILE * fopen(const char *name, const char *mode) { register int i; int rwmode = 0, rwflags = 0; FILE *stream; int fd, flags = 0; for (i = 0; _iotable[i] != 0 ; i++) if ( i >= FOPEN_MAX ) return (FILE *)NULL; switch(*mode++) { case 'r': flags |= _IOREAD; rwmode = O_RDONLY; break; case 'w': flags |= _IOWRITE; rwmode = O_WRONLY; rwflags = O_CREAT | O_TRUNC; break; case 'a': flags |= _IOWRITE; rwmode = O_WRONLY; rwflags |= O_APPEND | O_CREAT; break; default: return (FILE *)NULL; } while (*mode) { switch(*mode++) { case 'b': break; case '+': rwmode = O_RDWR; flags |= _IOREAD | _IOWRITE; break; default: return (FILE *)NULL; } } fd = open(name, rwmode | rwflags, PMODE); if (fd < 0) return (FILE *)NULL; if (( stream = (FILE *) malloc(sizeof(FILE))) == NULL ) { close(fd); return (FILE *)NULL; } stream->_count = 0; stream->_fd = fd; stream->_flags = flags; stream->_buf = 0; _iotable[i] = stream; return stream; }