--- name: "famd" section: "1m" platform: "linux" package: "fam" version: "2.6.6.1-5.2" release: "Debian 3.0 (Woody)" platforms: ["linux"] url: "https://new.carta.tech/famd" --- # famd(1m) file alteration monitor ## NAME fam - file alteration monitor ## SYNOPSIS ``` /usr/etc/fam [ -f | -v | -d ] [ -l | -t NFS_polling_interval ] [ -T idle_timeout ] [ -p program.version ] [ -L ] [ -C ] [ -c config_file ] ``` ## DESCRIPTION *fam* is a server that tracks changes to the filesystem and relays these changes to interested applications. Applications such as *fm*(1G) and *mailbox*(1) present an up-to-date view of the filesystem. In the absence of *fam*, these applications and others like them are forced to poll the filesystem to detect changes. *fam* is more efficient. Applications can request *fam* to monitor any files or directories in any filesystem. When *fam* detects changes to monitored files, it notifies the appropriate application. The FAM API provides a programmatic interface to *fam*; see *fam*(3X). *fam* is informed of filesystem changes as they happen by the kernel through the *imon*(7M) pseudo device driver. If asked to monitor files on an NFS mounted filesystem, *fam* tries to use *fam* on the NFS server to monitor files. If *fam* cannot contact a remote *fam*, it polls the files instead. *fam* also polls special files. Normally, *fam* is started by *inetd*(1M). It is registered with *portmap*(1M) as performing the sgi\_fam service. ## OPTIONS - **-l** Disable polling of NFS files. It does not disable use of remote *fam* on NFS servers, nor does it disable polling of local files. - **-t** *NFS\_polling\_interval* Set the interval for polling files to *NFS\_polling\_interval* seconds. The default is six seconds. - **-T** *idle\_timeout* Set the idle timeout interval to *idle\_timeout*. fam exits *idle\_timeout* seconds after its last client disconnects. A value of 0 causes fam to wait indefinitely for new connections. The default is five seconds. - **-f** Remain in the foreground instead of spawning a child and exiting. This option is ignored if *fam* is started by *inetd*. - **-v** Turn on verbose messages. - **-d** Enable verbose messages and debug messages. - **-p** *program***.***version* Use the specified RPC program and version numbers. - **-L** Local-only mode. *fam* will only accept requests from clients running on the local machine. This overrides the *local\_only* flag in the configuration file. This option is ignored if *fam* is started by *inetd*. - **-C** Compatibility mode. This disables authentication and reduces access security as described under SECURITY below. This overrides the *insecure\_compatibility* flag in the configuration file. - **-c** *config\_file* Read configuration information from the given file rather than the default, which is */etc/fam.conf*. ## CONFIGURATION FILE In addition to its command-line options, *fam*'s behavior can also be controlled through its configuration file. By default, this is */etc/fam.conf*; the **-c** command-line option can be used to specify an alternate file. Configuration lines are in the format *option=value*. Lines beginning with *#* or *!* are ignored. *fam* recognizes the following options: - **insecure\_compatibility** If set to *true*, this disables authentication and reduces access security as described under SECURITY below. This is *false* by default. Setting this option to *true* is the same as using the **-C** command-line option. - **untrusted\_user** This is the user name or UID of the user account which *fam* will use for unauthenticated clients. If a file can't be *stat*'ed by this user, *fam* will not tell unauthenticated clients about the file's existence. If an untrusted user is not given in the configuration file, *fam* will write an error message to the system log and terminate. - **local\_only** If set to *true*, *fam* will ignore requests from remote *fam*s. This is *false* by default. Setting this option to *true* is the same as using the **-L** command-line option. This option is ignored if *fam* is started by *inetd*. - **xtab\_verification** If set to *true*, *fam* will check the list of exported filesystems when remote requests are received to verify that the requests fall on filesystems which are exported to the requesting hosts. This is *true* by default. If this option is set to *false*, *fam* will service remote requests without attempting to perform the verification. If the *local\_only* configuration option or **-L** command-line option is used, *xtab\_verification* has no effect. ## SECURITY For backward compatibility, the **-C** command-line option and *insecure\_compatibility* configuration option can be used to disable authentication. Configuring *fam* this way opens a publically known security weakness whereby a "rogue client" can obtain the names of all the files and directories on the system. *Note that fam never opens the files it's monitoring*, and cannot be used by a rogue client to read the contents of any file on the system. *fam* only gives out the names of monitored files, and only monitors files which the client can *stat*(1M). Users can stat a file without having read permission on it as long as they have search permission on the directory containing it. ## FILES /etc/fam.conf ## SEE ALSO inetd(1M), portmap(1M), fam(3X), imon(7M), stat(1M).