open_excl(3)open_excl(3)NAMEopen_excl - open a file for exclusive writing
SYNTAX
#include <open.h>
int open_excl(const char *filename);
DESCRIPTIONopen_excl opens the file filename for writing and returns the file han‐
dle. 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).
SEE ALSOopen(2)open_excl(3)