4.3BSD - /usr/src/lib/libc/stdio/fopen.c

   1: /*
   2:  * Copyright (c) 1980 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if defined(LIBC_SCCS) && !defined(lint)
   8: static char sccsid[] = "@(#)fopen.c	5.2 (Berkeley) 3/9/86";
   9: #endif LIBC_SCCS and not lint
  10: 
  11: #include <sys/types.h>
  12: #include <sys/file.h>
  13: #include <stdio.h>
  14: 
  15: FILE *
  16: fopen(file, mode)
  17:     char *file;
  18:     register char *mode;
  19: {
  20:     register FILE *iop;
  21:     register f, rw, oflags;
  22:     extern FILE *_findiop();
  23: 
  24:     iop = _findiop();
  25:     if (iop == NULL)
  26:         return (NULL);
  27: 
  28:     rw = (mode[1] == '+');
  29: 
  30:     switch (*mode) {
  31:     case 'a':
  32:         oflags = O_CREAT | (rw ? O_RDWR : O_WRONLY);
  33:         break;
  34:     case 'r':
  35:         oflags = rw ? O_RDWR : O_RDONLY;
  36:         break;
  37:     case 'w':
  38:         oflags = O_TRUNC | O_CREAT | (rw ? O_RDWR : O_WRONLY);
  39:         break;
  40:     default:
  41:         return (NULL);
  42:     }
  43: 
  44:     f = open(file, oflags, 0666);
  45:     if (f < 0)
  46:         return (NULL);
  47: 
  48:     if (*mode == 'a')
  49:         lseek(f, (off_t)0, L_XTND);
  50: 
  51:     iop->_cnt = 0;
  52:     iop->_file = f;
  53:     iop->_bufsiz = 0;
  54:     if (rw)
  55:         iop->_flag = _IORW;
  56:     else if (*mode == 'r')
  57:         iop->_flag = _IOREAD;
  58:     else
  59:         iop->_flag = _IOWRT;
  60:     iop->_base = iop->_ptr = NULL;
  61:     return (iop);
  62: }

Defined functions

Defined variables