NAME

       clamd - an anti-virus daemon

SYNOPSIS

       clamd [options]

DESCRIPTION

       The  daemon  listens for incoming connections on Unix and/or TCP socket and scans files or directories on
       demand. It reads the configuration from /etc/clamav/clamd.conf

COMMANDS

       It's recommended to prefix clamd commands with the letter z (eg. zSCAN) to indicate that the command will
       be  delimited  by  a  NULL  character  and  that  clamd should continue reading command data until a NULL
       character is read. The null delimiter assures that the complete command and its entire argument  will  be
       processed  as  a single command. Alternatively commands may be prefixed with the letter n (e.g. nSCAN) to
       use a newline character as the delimiter. Clamd replies will honour the requested terminator in turn.  If
       clamd  doesn't  recognize the command, or the command doesn't follow the requirements specified below, it
       will reply with an error message, and close the connection.

       Clamd recognizes the following commands:

       PING   Check the server's state. It should reply with "PONG".

       VERSION
              Print program and database versions.

       RELOAD Reload the virus databases.

       SHUTDOWN
              Perform a clean exit.

       SCAN file/directory
              Scan a file or a directory  (recursively)  with  archive  support  enabled  (if  not  disabled  in
              clamd.conf). A full path is required.

       CONTSCAN file/directory
              Scan file or directory (recursively) with archive support enabled and don't stop the scanning when
              a virus is found.

       MULTISCAN file/directory
              Scan file in a standard way or scan directory (recursively) using multiple threads  (to  make  the
              scanning faster on SMP machines).

       ALLMATCHSCAN file/directory
              ALLMATCHSCAN  works  just  like  SCAN  except  that  it sets a mode where scanning continues after
              finding a match within a file.

       INSTREAM
              It is mandatory to prefix this command with n or z.

              Scan a stream of data. The stream is sent to clamd in chunks, after INSTREAM, on the  same  socket
              on  which  the command was sent.  This avoids the overhead of establishing new TCP connections and
              problems with NAT. The format of the chunk is: '<length><data>' where <length> is the size of  the
              following data in bytes expressed as a 4 byte unsigned integer in network byte order and <data> is
              the actual chunk. Streaming is terminated by sending a zero-length  chunk.  Note:  do  not  exceed
              StreamMaxLength  as  defined  in  clamd.conf,  otherwise clamd will reply with INSTREAM size limit
              exceeded and close the connection.

       FILDES It is mandatory to newline terminate this command, or prefix with n or z.

              This command only works on UNIX domain sockets.  Scan a file descriptor. After  issuing  a  FILDES
              command  a  subsequent  rfc2292/bsd4.4 style packet (with at least one dummy character) is sent to
              clamd carrying the file descriptor to be scanned inside the  ancillary  data.   Alternatively  the
              file descriptor may be sent in the same packet, including the extra character.

       STATS  It  is  mandatory  to  newline terminate this command, or prefix with n or z, it is recommended to
              only use the z prefix.

              Replies with statistics about the scan queue, contents of scan queue, and memory usage. The  exact
              reply format is subject to change in future releases.

       IDSESSION, END
              It  is  mandatory  to  prefix  this command with n or z, and all commands inside IDSESSION must be
              prefixed.

              Start/end a clamd session. Within a  session  multiple  SCAN,  INSTREAM,  FILDES,  VERSION,  STATS
              commands  can  be sent on the same socket without opening new connections. Replies from clamd will
              be in the form '<id>: <response>' where <id> is the request number (in ascii, starting from 1) and
              <response>  is  the  usual  clamd reply.  The reply lines have same delimiter as the corresponding
              command had.  Clamd will process the commands asynchronously, and reply as soon as it has finished
              processing.

              Clamd  requires  clients  to read all the replies it sent, before sending more commands to prevent
              send() deadlocks. The recommended way to implement a client  that  uses  IDSESSION  is  with  non-
              blocking  sockets,  and  a  select()/poll()  loop: whenever send would block, sleep in select/poll
              until either you can write more data, or read more replies.  Note that using non-blocking  sockets
              without   the   select/poll  loop  and  alternating  recv()/send()  doesn't  comply  with  clamd's
              requirements.

              If clamd detects that a client has deadlocked,  it will close the connection. Note that clamd  may
              close  an IDSESSION connection too if you don't follow the protocol's requirements. The client can
              use the PING command to keep the connection alive.

       VERSIONCOMMANDS
              It is mandatory  to  prefix  this  command  with  either  n  or  z.   It  is  recommended  to  use
              nVERSIONCOMMANDS.

              Print  program  and  database  versions,  followed  by "| COMMANDS:" and a space-delimited list of
              supported commands.  Clamd <0.95 will recognize this as the VERSION command, and reply  only  with
              their version, without the commands list.

              This command can be used as an easy way to check for IDSESSION support for example.

       DEPRECATED COMMANDS

       STREAM Scan  stream - on this command clamd will return "PORT number" you should connect to and send data
              to scan. (DEPRECATED, use INSTREAM instead)

       NOT SUPPORTED COMMANDS

       SESSION, END
              Start/end a clamd session which will allow you to run multiple  commands  per  TCP  session.  (use
              IDSESSION instead)

OPTIONS

       -h, --help
              Output help information and exit.

       -V, --version
              Print the version number and exit.

       -F, --foreground
              Run in foreground; do not daemonize.

       --debug
              Enable debug mode.

       -c FILE, --config-file=FILE
              Read configuration from FILE.

ENVIRONMENT VARIABLES

       clamd uses the following environment variables:

       LD_LIBRARY_PATH  -  May be used on startup to find the libclamunrar_iface shared library module to enable
       RAR archive support.

SIGNALS

       Clamd recognizes the following signals:

       SIGHUP Reopen the logfile.

       SIGUSR2
              Reload the signature databases.

       SIGTERM
              Perform a clean exit.

FILES

       /etc/clamav/clamd.conf

CREDITS

       Please check the full documentation for credits.

AUTHOR

       Tomasz Kojm <tkojm@clamav.net>

SEE ALSO

       clamd.conf(5), clamdscan(1), freshclam(1), freshclam.conf(5), clamav-milter(8)