cuFileIo.c   [plain text]

/*
 * Copyright (c) 2001-2003 Apple Computer, Inc. All Rights Reserved.
 * 
 * The contents of this file constitute Original Code as defined in and are
 * subject to the Apple Public Source License Version 1.2 (the 'License').
 * You may not use this file except in compliance with the License. Please 
 * obtain a copy of the License at http://www.apple.com/publicsource and 
 * read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 * Please see the License for the specific language governing rights and 
 * limitations under the License.
 */
 
/*
	File:		 cuFileIo.c 
	
	Description: simple file read/write utilities
*/

#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "cuFileIo.h"

int writeFile(
	const char			*fileName,
	const unsigned char	*bytes,
	unsigned			numBytes)
{
	int		rtn;
	int 	fd;
	
	fd = open(fileName, O_RDWR | O_CREAT | O_TRUNC, 0600);
	if(fd <= 0) {
		return errno;
	}
	rtn = lseek(fd, 0, SEEK_SET);
	if(rtn < 0) {
		return errno;
	}
	rtn = write(fd, bytes, (size_t)numBytes);
	if(rtn != (int)numBytes) {
		if(rtn >= 0) {
			printf("writeFile: short write\n");
		}
		rtn = EIO;
	}
	else {
		rtn = 0;
	}
	close(fd);
	return rtn;
}
	
/*
 * Read entire file. 
 */
int readFile(
	const char		*fileName,
	unsigned char	**bytes,		// mallocd and returned
	unsigned		*numBytes)		// returned
{
	int rtn;
	int fd;
	char *buf;
	struct stat	sb;
	unsigned size;
	
	*numBytes = 0;
	*bytes = NULL;
	fd = open(fileName, O_RDONLY, 0);
	if(fd <= 0) {
		return errno;
	}
	rtn = fstat(fd, &sb);
	if(rtn) {
		goto errOut;
	}
	size = sb.st_size;
	buf = malloc(size);
	if(buf == NULL) {
		rtn = ENOMEM;
		goto errOut;
	}
	rtn = lseek(fd, 0, SEEK_SET);
	if(rtn < 0) {
		goto errOut;
	}
	rtn = read(fd, buf, (size_t)size);
	if(rtn != (int)size) {
		if(rtn >= 0) {
			printf("readFile: short read\n");
		}
		rtn = EIO;
	}
	else {
		rtn = 0;
		*bytes = buf;
		*numBytes = size;
	}
errOut:
	close(fd);
	return rtn;
}