Thread: Error using File Descriptor

HelloI am trying to figure out why I am getting an error (-1) when tryingto write to a file.

Hereis the function - I did not include the rest of the code - not sureif I am leaving anything else out - I assumed it was a writepermission issue?

Code:

#defineDATAFILE "/var/chance.data" //File to store userdata

voidregister_new_player() {  int fd;

printf("-=-={New Player Registration } =-=-\n");
printf("Enteryour name: ");
input_name();

player.uid= getuid();
player.highscore= player.credits = 100;

fd= open(DATAFILE, O_WRONLY|O_CREAT|O_APPEND, S_IRUSR|S_IWUSR);
if(fd= -1)
fatal("in register_new_player() while opening file");
write(fd,&player, sizeof(struct user));
close(fd);

printf("\nWelcometo the Game of Chance %s\n", player.name);
printf("Youhave been given %u credits.\n", player.credits);
}

Hereare my file/folder Permissions

PHP Code:

folder:/var:rwxrwxrwt root:root
file:/var/chance.data:-rwxrw---- root:user 


Imodified the permission for chance.data manually in attempt tofix.

originalpermissions

PHP Code:

-rw-------root:user 


PHP Code:

./game_of_chance:rwsrwxr-x root:root
game_of_chance.c:-rw-rw-r-- user:user 


Result

Code:

user@ubuntu:~/examples$./game_of_chance 
-=-={New Player Registration } =-=-
Enteryour name: test
[!!]Fatal Error in register_new_player() while opening file:Success
user@ubuntu:~/examples$

Thank you - I just noticed it while comparing back to the original. I spent a few hours looking at permissions. I hope one day I get a grip on this. Thanks again

Originally Posted by sjmp

Thank you - I just noticed it while comparing back to the original. I spent a few hours looking at permissions. I hope one day I get a grip on this. Thanks again

You should be compiling at the maximum warning level. Any decent compiler nowadays will warn you if you appear to be mixing up = and == if you turn up the warnings.