open_excl − open a file for exclusive writing
#include <libowfat/open.h>
int open_excl(const char *filename);
open_excl opens the file filename for writing and returns the file handle. The file may not exist before the call to open_excl. The file will be created with mode 0600.
If there was an error creating the file, open_excl returns -1 and sets errno accordingly.
Since open_excl relies on the O_EXCL flag to open, it does not work reliably over NFS (the NFS protocol is broken) and must be emulated using a lock file (create a file with a unique file name and link(2) it to the lock file. Then stat the lock file and see if the link count is 2).
open(2), open_append(3), open_read(3), open_rw(3), open_trunc(3), open_write(3), openreadclose(3), readclose(3), readclose_append(3)