write.c

《嵌入式Linux应用程序开发详解》一书的源代码之第六章

/*write.c*/
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define MAXSIZE
int main(void)
{
	int i,fd,size,len;
	char *buf="Hello! I'm writing to this file!";
	char buf_r[10];
	len = strlen(buf);
	buf_r[10] = '\0';
	if((fd = open("/tmp/hello.c", O_CREAT | O_TRUNC | O_RDWR,0666 ))<0){
		perror("open:");
		exit(1);
	}
	else
		printf("open file:hello.c %d\n",fd);

	if((size = write( fd, buf, len)) < 0){
		perror("write:");
		exit(1);
	}
	else
		printf("Write:%s\n",buf);

	lseek( fd, 0, SEEK_SET ); 
	if((size = read( fd, buf_r, 10))<0){ 
		perror("read:");
		exit(1);
	}
	else
		printf("read form file:%s\n",buf_r);
	if( close(fd) < 0 ){
		perror("close:");
		exit(1);
	}
	else
		printf("Close hello.c\n");
	exit(0);
}