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RZ(1)											    RZ(1)

NAME
       rx, rb, rz - XMODEM, YMODEM, ZMODEM (Batch) file receive

SYNOPSIS
       rz [- +8abeOpqRtTuUvy]
       rb [- +abqRtuUvy]
       rx [- abceqRtuUv] file
       [-][v]rzCOMMAND

DESCRIPTION
       This  program  uses error correcting protocols to receive files over a dial-in serial port
       from a variety of programs running under PC-DOS, CP/M, Unix, and other operating  systems.
       It  is  invoked	from a shell prompt manually, or automatically as a result of an "sz file
       ..." command given to the calling program.

       While rz is smart enough to be called from cu(1), very few versions  of	cu(1)  are  smart
       enough  to  allow rz to work properly.  Unix flavors of Professional-YAM are available for
       such dial-out application.

       Rz (Receive ZMODEM) receives files with the ZMODEM batch protocol.  Pathnames are supplied
       by  the	sending program, and directories are made if necessary (and possible).	Normally,
       the "rz" command is automatically issued by the calling ZMODEM program, but some defective
       ZMODEM implementations may require starting rz the old fashioned way.

       Rb  receives  file(s) with YMODEM, accepting either standard 128 byte sectors or 1024 byte
       sectors (YAM sb -k option).  The user should determine when the	1024  byte  block  length
       actually improves throughput without causing lost data or even system crashes.

       If  True  YMODEM  (Omen	Technology  trademark)	file  information (file length, etc.)  is
       received, the file length controls the number of bytes written to the output dataset,  and
       the modify time and file mode (iff non zero) are set accordingly.

       If  no  True  YMODEM  file information is received, slashes in the pathname are changed to
       underscore, and any trailing period in the pathname is  eliminated.   This  conversion  is
       useful  for files received from CP/M systems.  With YMODEM, each file name is converted to
       lower case unless it contains one or more lower case letters.

       Rx receives a single file with XMODEM or XMODEM-1k protocol.  The  user	should	determine
       when  the  1024	byte  block length actually improves throughput without causing problems.
       The user must supply the file name to both sending and receiving  programs.   Up  to  1023
       garbage characters may be added to the received file.

       Rz may be invoked as rzCOMMAND (with an optional leading - as generated by login(1)).  For
       each received file, rz will pipe the file to ``COMMAND filename'' where	filename  is  the
       name of the transmitted file with the file contents as standard input.

       Each file transfer is acknowledged when COMMAND exits with 0 status.  A non zero exit sta-
       tus terminates transfers.

       A typical use for this form is rzrmail which calls rmail(1) to post mail to the user spec-
       ified  by  the  transmitted  file name.	For example, sending the file "caf" from a PC-DOS
       system to rzrmail on a Unix system would result in the contents	of  the  DOS  file  "caf"
       being mailed to user "caf".

       On  some  Unix  systems,  the login directory must contain a link to COMMAND as login sets
       SHELL=rsh which disallows absolute pathnames.  If invoked with a leading ``v'', rz will be
       verbose (see v option).	The following entry works for Unix SYS III/V:
				 rzrmail::5:1::/bin:/usr/local/rzrmail
       If the SHELL environment variable includes rsh , rbash or rksh (restricted shell), rz will
       not accept absolute pathnames or references to a parent	directory,  will  not  modify  an
       existing file, and removes any files received in error.

       If  rz is invoked with stdout and stderr to different datasets, Verbose is set to 2, caus-
       ing frame by frame progress reports to stderr.  This may be disabled with the q option.

OPTIONS
       The meanings of the available options are:

       -+, --append
	      append received data to an existing file (ZMODEM, ASCII only).
       -a, --ascii
	      Convert files to Unix conventions by stripping carriage returns and all  characters
	      beginning with the first Control Z (CP/M end of file).
       -b, --binary
	      Binary (tell it like it is) file transfer override.
       -B NUMBER, --bufsize NUMBER
	      Buffer  NUMBER  bytes  before  writing  to disk. Default ist 32768, which should be
	      enough for most situations. If you have a slow machine or a bad disk  interface  or
	      suffer  from other hardware problems you might want to increase the buffersize.  -1
	      or auto use a buffer large enough to buffer the whole file. Be  careful  with  this
	      options - things normally get worse, not better, if the machine starts to swap.
       -c, --with-crc
	      XMODEM only. Use 16 bit CRC (normally a one byte checksum is used).
       -C, --allow-remote-commands
	      allow  remote  command execution ( insecure ). This allows the sender to execute an
	      arbitrary command through system () or execl (). Default is to disable this feature
	      (?). This option is ignored if running in restricted mode.
       -D, --null
	      Output file data to /dev/null; for testing.  (Unix only)
       --delay-startup N
	      Wait N seconds before doing anything.
       -e, --escape
	      Force  sender  to  escape all control characters; normally XON, XOFF, DLE, CR-@-CR,
	      and Ctrl-X are escaped.
       -E, --rename
	      Rename incoming file if target filename already exists. The new file name will have
	      a dot and a number (0..999) appended.
       -h, --help
	      give help screen.
       -m N, --min-bps N
	      Stop  transmission  if BPS-Rate (Bytes Per Second) falls below N for a certain time
	      (see --min-bps-time option).
       -M N, --min-bps-time
	      Used together with --min-bps. Default is 120 (seconds).
       -O, --disable-timeouts
	      Disable read timeout handling code. This makes lrz hang if the sender does not send
	      any  more,  but  increases  performance  (a bit) and decreases system load (through
	      reducing the number of system calls by about 50 percent).

	      Use this option with care.
       --o-sync
	      Open output files in synchronous write mode. This may be useful if  you  experience
	      errors  due  to  lost  interrupts  if  update (or bdflush or whoever this daemon is
	      called on your system) writes the buffers to the disk.

	      This option is ignored and a warning is printed if  your	systems  doesn't  support
	      O_SYNC.
       -p, --protect
	      (ZMODEM) Protect: skip file if destination file exists.
       -q, --quiet
	      Quiet suppresses verbosity.
       -r, --resume
	      Crash recovery mode. lrz tries to resume interrupted file transfers.
       -R, --restricted
	      Enter more restricted mode. lrz will not create directories or files with a leading
	      dot if this option is given twice.

	      See SECURITY for mode information about restricted mode.
       -s HH:MM, --stop-at HH:MM
	      Stop transmission at HH hours, MM minutes. Another variant,  using  +N  instead  of
	      HH:MM, stops transmission in N seconds.
       -S, --timesync
	      Request  timesync packet from the sender. The sender sends its system time, causing
	      lrz to complain about more then 60 seconds difference.

	      Lrz tries to set the local system time to the remote time if this option	is  given
	      twice (this fails if lrz is not run by root).

	      This  option makes lrz incompatible with certain other ZModems. Don't use it unless
	      you know what you are doing.
       --syslog[=off]
	      turn syslogging on or off. the default is set at configure time.	 This  option  is
	      ignored if no syslog support is compiled in.
       -t TIM, --timeout TIM
	      Change  timeout  to  TIM	tenths of seconds. This is ignored if timeout handling is
	      turned of through the O option.
       --tcp-client ADDRESS:PORT
	      Act as a tcp/ip client: Connect to the given port.

	      See --tcp-server for more information.

       --tcp-server
	      Act as a server: Open a socket, print out what to do, wait for connection.

	      You will normally not want to use this option as lrzsz is  the  only  zmodem  which
	      understands  what to do (private extension). You might want to use this if you have
	      to use zmodem (for which reason whatever), and cannot use the --tcp option  of  lsz
	      (perhaps because your telnet doesn't allow to spawn a local program with stdin/std-
	      out connected to the remote side).

	      If you use this option you have to start lsz  with  the  --tcp-client  ADDRESS:PORT
	      option.  lrz will print the address and port on startup.

	      Use of this option imposes a security risk, somebody else could connect to the port
	      in between. See SECURITY for details.
       -U, --unrestrict
	      turn off restricted mode (this is  not  possible	if  running  under  a  restricted
	      shell).
       --version
	      prints out version number.
       -v, --verbose
	      Verbose  causes  a  list of file names to be appended to stderr.	More v's generate
	      more output.
       -wN, --windowsize N
	      Set window size to N.
       -X, --xmodem
	      use XMODEM protocol.
       -y, --overwrite
	      Yes, clobber any existing files with the same name.
       --ymodem
	      use YMODEM protocol.
       -Z, --zmodem
	      use ZMODEM protocol.

SECURITY
       Contrary to the original ZMODEM lrz defaults to restricted mode. In  restricted	mode  lrz
       will not accept absolute pathnames or references to a parent directory, will not modify an
       existing file, and removes any files received in error. Remote command execution  is  dis-
       abled.

       To use a more restricted mode set the environment variable ZMODEM_RESTRICTED or give the R
       option. This disables creation of subdirectories and invisible files.

       Restricted mode may be turned off with the U option, unless lrz runs  under  a  restricted
       shell.

       Use of the
	      --tcp-client  or	--tcp-server  options  imposes	a security risk, as somebody else
	      could connect to the port before you do it, and grab your data. If  there's  strong
	      demand for a more secure mode i might introduce some sort of password challenge.

ENVIRONMENT
       lrz uses the following environment variables:

       SHELL  lrz recognizes a restricted shell if this variable includes rsh or rksh

       ZMODEM_RESTRICTED
	      lrz enters the more restricted mode if the variable is set.

EXAMPLES
(Pro-YAM command)
<ALT-2>
Pro-YAM Command: sz *.h *.c
(This automatically invokes rz on the connected system.)

SEE ALSO
       ZMODEM.DOC, YMODEM.DOC, Professional-YAM, crc(omen), sz(omen), usq(omen), undos(omen)

       Compile	time  options  required for various operating systems are described in the source
       file.

NOTES
       Sending serial data to timesharing minicomputers at sustained high speeds has  been  known
       to  cause lockups, system halts, kernel panics, and occasional antisocial behaviour.  When
       experimenting with high speed input to a system, consider rebooting the system if the file
       transfers are not successful, especially if the personality of the system appears altered.

       The Unix "ulimit" parameter must be set high enough to permit large file transfers.

       The  TTY  input	buffering on some systems may not allow long blocks or streaming input at
       high speed.  You should suspect this problem when you can't send data to the  Unix  system
       at  high  speeds  using	ZMODEM,  YMODEM-1k or XMODEM-1k, when YMODEM with 128 byte blocks
       works properly.	If the system's tty line handling is really broken, the  serial  port  or
       the entire system may not survive the onslaught of long bursts of high speed data.

       The DSZ or Pro-YAM zmodem l numeric parameter may be set to a value between 64 and 1024 to
       limit the burst length ("zmodem pl128").

       32 bit CRC code courtesy Gary S. Brown.	Directory creation code from  John  Gilmore's  PD
       TAR program.

BUGS
       Calling rz from most versions of cu(1) doesn't work because cu's receive process fights rz
       for characters from the modem.

       Programs that do not properly implement the specified file transfer protocol may cause  sz
       to  "hang" the port for a minute or two.  Every reported instance of this problem has been
       corrected by using ZCOMM, Pro-YAM, or other program with a correct implementation  of  the
       specified protocol.

       Many  programs  claiming  to  support  YMODEM only support XMODEM with 1k blocks, and they
       often don't get that quite right.

       Pathnames are restricted to 127 characters.  In XMODEM  single  file  mode,  the  pathname
       given on the command line is still processed as described above.  The ASCII option's CR/LF
       to NL translation merely deletes CR's; undos(omen) performs a  more  intelligent  transla-
       tion.

VMS VERSION
       The VMS version does not set the file time.

       VMS C Standard I/O and RMS may interact to modify file contents unexpectedly.

       The  VMS  version does not support invocation as rzCOMMAND .  The current VMS version does
       not support XMODEM, XMODEM-1k, or YMODEM.

       According to the VMS documentation, the buffered input routine used on the VMS version  of
       rz  introduces  a delay of up to one second for each protocol transaction.  This delay may
       be significant for very short files.  Removing the "#define BUFREAD" line from  rz.c  will
       eliminate this delay at the expense of increased CPU utilization.

       The  VMS  version  causes  DCL  to generate a random off the wall error message under some
       error conditions; this is a result of the incompatibility of the VMS "exit" function  with
       the Unix/MSDOS standard.

ZMODEM CAPABILITIES
       Rz  supports  incoming  ZMODEM  binary  (-b),  ASCII (-a), protect (-p), clobber (-y), and
       append (-+) requests.  The default is protect (-p) and binary (-b).

       The Unix versions support ZMODEM command execution.

FILES
       rz.c, crctab.c, rbsb.c, zm.c, zmodem.h Unix source files.

       rz.c, crctab.c, vrzsz.c, zm.c, zmodem.h, vmodem.h, vvmodem.c, VMS source files.

					       OMEN					    RZ(1)
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