c file io

file_read.c

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>

int main() {
        int fd = open("foo.txt", O_RDWR | O_CREAT, 0644);

        if(fd < 0) {
                printf("failed\n");
                return -1;
        }

        printf("success\n");
        printf("fd: %d\n", fd);

        char buf[10];

        read(fd, buf, 10);
        close(fd);

        printf("file content: %s", buf);

        return 0;
}

file_write.c

#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>

int main() {
        int fd = open("foo.txt", O_RDWR | O_CREAT, 0644);

        if(fd < 0) {
                printf("failed\n");
                return -1;
        }

        printf("success\n");
        printf("fd: %d\n", fd);

        write(fd, "hello", 5);
        close(fd);

        return 0;
}