Q:

im trying to run a program that copy the text from one file to the other

im trying to write a program that gets two text files and copy`s the text from one file to the other.
the function seems to be working but it changes the file that I write in not in to a text file. 
please help!!!!
int main(int argc, char *argv[]) {
    printf("Hello World!\n"); 
    char* file1 = argv[1];
    char* file2 = argv[2];
    char buffer1[SIZE+1];
    //char buffer2[SIZE+1];
    int fd1, fd2;
    int run = 1;
    int run2;

    fd1 = open(file1, O_RDONLY);

    if(fd1 < 0){
        perror("after open ");   // checks if the file was open ok 
        exit(-1);   
    }

    fd2 = open(file2, O_RDWR );

        if(fd2 < 0){
        perror("after open ");   // checks if the file was open ok  
        exit(-1);
        }

    while(run != 0){
        run = read(fd1, buffer1, SIZE);     
        run2 = write(fd2, buffer1, SIZE);
        printf("run 2: %d", run2);
    }

    close(fd1);
    close(fd2);
    return 1;

}

A:

Probably because 
 fd2 = open(file2, O_RDONLY);

Read only file -> fd2

