Linux C I/O creat/open/read/write/close

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/*Linux C :Copy oldFilePath to newFilePath by ZhaoXuyang at 2018-05-24 02:23*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>

int main(){
    char oldFilePath[255];
    char newFilePath[255];
    printf("Copy oldFile to newFile:\n");
    printf("Input old file path:");
    scanf("%s",oldFilePath);
    printf("Input new file path:");
    scanf("%s",newFilePath);

    int fd1=open(oldFilePath,O_RDONLY);
    if(fd1<0){
        printf("Can't open %s\n",oldFilePath);
        exit(1);
    }

    int fd2=open(newFilePath,O_CREAT|O_TRUNC|O_RDWR,0644);
    if(fd2<0){
        printf("Can't open %s\n",newFilePath);
        exit(1);
    }

    int words;
    const int len=255;
    char buf[len];
    while((words=read(fd1,buf,len))>0){
        int n=write(fd2,buf,words);
        if(n<0){
            printf("Write fail!\n");
            exit(1);
        }
    }

    close(fd2);
    close(fd1);
    return 0;
}