Both programs use the same command line options, there is no difference between these options.
drop | alert [-bDFhlpTvV] [-Adelay] [-cconfig ] [-ddomain] [-ffrom] [-Llevel] [-mmode] [-Mmax] [-pport] [-PPIDfile] [-rrcpt] [-ssocket] [-Sserver] [-wdir]
The alert and drop options in detail
-A delayTry every
delay seconds to send an email if
there are any alerts in the buffer.
-bStart in daemon mode, switch to a background
process. This automatically activates the option -l.
-c
configThis defines the name of the configuration file to use.
-d domainUse domain as HELO string on
a connection to the MailServer, see
option -S.
-f fromSets the sender
address of the emails to from.
-FTry to resolve the sensor names via DNS.
-hPrint a help text and exit.
-lPrint via syslog instead of
stdout.
-L levelIf a number of
level alerts are buffered then
send an email. A value of zero disables this feature.
-m modeSets the umask to
mode for the daemon
mode. This affects the mode for the created unix socket and
PID file. The mode can be either given in ascii,
octal (with leading 0) or
hex (with leading 0x)
format.
-M maxcountSpecifies the
maximum number of tries to send an email. If still no email could be
send the program alert exits and the program
drop prints all alerts to
stdout or syslog, see option
-l.
-p portTry to reach the
mail server on this port. The default is port 25, see also option
-S.
-P
PIDFileSpecifies which file should be used to store the PID. This file must be writeable by the user running alert/drop!
-r recipientSets the address of one recipient for the emails. This option can be used several times to build a list of recipients.
-s
socketnameSpecifies which unix domain socket of type datagram should be opened to listen for alerts.
-S serverSpecifies the mail server which should be used to send the emails. This server should allow relaying for the server running alert or drop.
-vPrint version information and exit.
-VActivates the verbose mode, some useful informations are printed if an email is sent. This is useful for debugging if there are any problems with the mail server.
-w dirSets the working
directory in daemon mode to dir.
The default is to use the current working directory. It is useful to
choose / to avoid blocking of mounted
filesystems.