fcons.c
上传用户:xiejiait
上传日期:2007-01-06
资源大小:881k
文件大小:2k
- /* @(#)fcons.c 2.7 98/02/15 Copyright 1986, 1995 J. Schilling */
- /*
- * Copyright (c) 1986, 1995 J. Schilling
- */
- /*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; see the file COPYING. If not, write to
- * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
- */
- #include <stdio.h>
- #include "io.h"
- LOCAL char *fmtab[] = {
- "", /* 0 FI_NONE */
- "r", /* 1 FI_READ */
- "w", /* 2 FI_WRITE **1) */
- "r+", /* 3 FI_READ | FI_WRITE */
- "b", /* 4 FI_NONE | FI_BINARY */
- "rb", /* 5 FI_READ | FI_BINARY */
- "wb", /* 6 FI_WRITE | FI_BINARY **1) */
- "r+b", /* 7 FI_READ | FI_WRITE | FI_BINARY */
- };
- /*
- * NOTES:
- * 1) fdopen() guarantees not to create/trunc files in this case
- *
- * "w" will create/trunc files with fopen()
- * "a" will create files with fopen()
- */
- FILE *_fcons(fd, f, flag)
- register FILE *fd;
- int f;
- int flag;
- {
- int my_gflag = _io_glflag;
- if (fd == (FILE *)NULL)
- fd = fdopen(f, fmtab[flag&(FI_READ|FI_WRITE|FI_BINARY)]);
- if (fd != (FILE *)NULL) {
- if (flag & FI_APPEND) {
- (void) fseek(fd, 0L, 2);
- }
- if (flag & FI_UNBUF) {
- setbuf(fd, NULL);
- my_gflag |= _IOUNBUF;
- }
- set_my_flag(fd, my_gflag); /* must clear it if fd is reused */
- return (fd);
- }
- if (flag & FI_CLOSE)
- close (f);
- return ((FILE *) NULL);
- }