TFTP(1C)                             BSD                              TFTP(1C)



NAME
     tftp - trivial file transfer protocol

SYNOPSIS
     tftp [ -g|g!|p|r|w ]  local_file host remote_file [mode]

DESCRIPTION
     The tftp command uses the Trivial File Transfer Protocol (TFTP) to copy
     files among internet hosts without remote user-level access.

     tftp requires an option to dictate the direction of the file transfer.
     The recognized options are:

     put (-p, -w)
                Write the local file (local_file) onto the remote host's file
                system as remote_file.  Note that remote_file must be quoted
                if it contains special shell characters.  (The word put, the
                option -p, and the option -w are all synonymous).

     get (-g, -r)
                Read the remote host's file (remote_file) into the local file
                (local_file).  If local_file already exists, tftp will fail
                with an appropriate error message.

     get! (-g!) Perform a tftp get, overwriting the local file (if it exists).
                Note that the exclamation point following the command
                indicates that the command will modify a data structure (in
                this case, it will overwrite an existing file; the syntax is
                derived from the Yale/T and MIT/Scheme naming conventions).
                Within a UNIX shell, the exclamation point must be escaped
                (usually with a backslash) to avoid shell interpretation.

     The user must have read and write access to files on the local host.
     Files transferred to the local host are either created or overwritten,
     but never appended to.  A minus sign (-) may be substituted for
     local_file, in which case the standard input (or output) will be used.

     The tftpd(8C) server running on the remote host imposes security
     restrictions on which remote files may be read and written.  These
     restrictions differ for various tftpd implementations.  For remote hosts
     running the Domain/OS tftpd server, remote_file must be a pathname
     beginning with "/" but not with "//" and not containing the string
     "/../". In addition, remote_file must either contain the string "/tftp"
     or begin with one of the directory names specified by the tftpd command
     when that server was invoked.  Furthermore, remote files may be read only
     if the tftpd userid configured on the remote host has read access to
     them, and remote files may be written only if they do not already exist
     and if the configured tftpd userid has write access to them.

     mode may be netascii or image. The default mode, netascii, transfers the
     file as standard ascii characters.  image mode transfers the file in
     binary without character conversion.

NOTE
     The Domain/OS versions of tftp and tftpd are adaptations of the MIT
     Project Athena implementation of the TFTP protocol, as described in
     RFC783.  Domain/OS tftp will interface with any RFC783-compliant
     implementation.  Note, however, that the 4.3BSD distribution version of
     tftp does not meet these restrictions.

WARNING

     tftp allows users to copy files across an internet without login or
     authentication on any remote host running a tftpd server.  If the tftpd
     server on a host is configured and run to allow tftp transactions, the
     file access restrictions imposed by that tftpd server provide the only
     security for files on that host.  Therefore, the desired security of a
     host should be considered before configuring and running the tftpd server
     to allow tftp transactions.

EXAMPLES
     Each of the following examples presumes that there is a host on the
     internet called hosta, running a tftpd server.

     1.   tftp -p filea hosta /tftp/filex

     Copies the local file filea to hosta, and deposits it in hosta's /tftp
     directory under the name filex.

     2.   tftp get fileb hosta /usr/tftpdir/filey

     Copies the remote file (on hosta) named /usr/tftpdir/filey to the local
     file named fileb.

     3.   tftp -g\! filec hosta /tftp/filez image

     Copies  the remote binary file (on hosta) named /tftp/filez to the local
     file named filec, overwriting the old copy of filec.

     With UNIX C shells, the exclamation point must be escaped, usually with a
     backslash as shown in this example, to avoid interpretation by the shell.

SEE ALSO
     tftpd(8C);
     Configuring and Managing TCP/IP;
     Using TCP/IP Network Applications.