Add a warning against modifying this code without understanding it, and

an example of how not to make it more portable.  I've had this lying
around uncommitted since 2009...
This commit is contained in:
des 2016-11-24 14:50:21 +00:00
parent 35247e2293
commit bf4eabbbec

View File

@ -1,5 +1,5 @@
/*-
* Copyright (c) 2007 Dag-Erling Coïdan Smørgrav
* Copyright (c) 2007-2009 Dag-Erling Coïdan Smørgrav
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -37,6 +37,14 @@ __FBSDID("$FreeBSD$");
#include <libutil.h>
/*
* Reliably open and lock a file.
*
* DO NOT, UNDER PAIN OF DEATH, modify this code without first reading the
* revision history and discussing your changes with <des@freebsd.org>.
* Don't be fooled by the code's apparent simplicity; there would be no
* need for this function if it was as easy to get right as you think.
*/
int
flopen(const char *path, int flags, ...)
{
@ -100,6 +108,14 @@ flopen(const char *path, int flags, ...)
errno = serrno;
return (-1);
}
#ifdef DONT_EVEN_THINK_ABOUT_IT
if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) {
serrno = errno;
(void)close(fd);
errno = serrno;
return (-1);
}
#endif
return (fd);
}
}