harvey/sys/src/libstdio/sclose.c

/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

/*
 * pANS stdio -- sclose
 */
#include "iolib.h"
char *sclose(FILE *f){
	switch(f->state){
	default:	/* ERR CLOSED */
		if(f->buf && f->flags&BALLOC)
			free(f->buf);
		f->flags=0;
		return NULL;
	case OPEN:
		f->buf=malloc(1);
		f->buf[0]='\0';
		break;
	case RD:
	case END:
		f->flags=0;
		break;
	case RDWR:
	case WR:
		if(f->wp==f->rp){
			if(f->flags&BALLOC)
				f->buf=realloc(f->buf, f->bufl+1);
			if(f->buf==NULL) return NULL;
		}
		*f->wp='\0';
		f->flags=0;
		break;
	}
	f->state=CLOSED;
	f->flags=0;
	return f->buf;
}