"crontab /etc/crontab", but not the same format due to the who field.
Add some limited anti-foot-shooting support and refuse to load
/etc/crontab as someone's crontab. Users wishing shoot their foot in
this manner may copy /etc/crontab elsewhere. :)
MFC After: 1 week
$ crontab -e
[Add an entry with an error in the crontab file.]
crontab: errors in crontab file, can't install
Do you want to retry the same edit? yes
[Exit the editor without any changes.]
crontab: no changes made to crontab
[Entry is lost.]
Now crontab will loop until the error is fixed, or the
user answers no.
program to read any file which is a valid crontab file.
The fix is based on that used in NetBSD and OpenBSD - we keep the
file open while the user is editing it. This means that files must
be edited in place. Cron attempts to warn you if your editor does
not do this. The fact that the file must be edited in place is also
noted in the man page.
This patch has been confirmed to work by atleast one person on
-security and has been tested locally.
Obtained from: OpenBSD
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
used by OpenBSD. (Quite frankly, I think it's perfectly reasonable to
use snprintf to copy strings, given that the semantics for strncpy()
are utterly idiotic and there is no POSIX sstrncpy().)
While I'm at it, incorporate some of OpenBSD's bugfixes to cron.
NOT for 2.2