How do I take input from user using read system call and store in a file using write system call. In C

@Richard-MacCutchan. Thank you for the correction.

I have corrected my code and now it looks as follows:



#define O_RDWR 0x0002
#define O_CREAT 0x0100
#define USERNAME_SIZE 10

int main()
{

int fd;

fd = open("user.dat", O_CREAT | O_RWDR, 0666);
if (fd == -1)
{
write(1,"There is an error opening the file",35);
}

write(1,"Enter the username",18);


char username[USERNAME_SIZE];
char c;
int count = 0;
do
{
read(0, &c, 1);
if (c == '\n')
break;
username[count++] = c;
}
while (count < USERNAME_SIZE - 1);
username[count] = 0;

write(fd,username,count);

close(fd);

return 0;
}



-----However on running it, I am getting an error saying There was an error opening the file ( I assume the file is not getting created. )What exactly should I do in this case?
If the file is present the code runs fine.

@Richard-MacCutchan.

Thank you for your guidance. I was able to get the program running now .

Would you be able to help me or guide me how compare 2 strings without using strcmp function?