




Command:   sz - send a file using the zmodem protocol
Syntax:    sz [-LNbdefnopqruvy+] [-ci command] [-Ll n] [-t timeout]
Flags:     -L  Use n-byte packets
           -N  Overwrite if source is newer/longer
           -b  Binary file
           -c  Send command for execution
           -d  Convert dot to slash in names
           -e  Escape for all control characters
           -f  Send full path name
           -i  Send command and return immediately
           -l  Flow control every n packets
           -n  Overwrite destination if source is newer
           -o  Use old (16-bit) checksum
           -p  Protect file if it already exists
           -q  Quiet; opposite of verbose
           -r  Resume interrupt file transfer
           -t  Set timeout in tenths of a second
           -u  Unlink file after successful transmission
           -v  Verbose; opposite of quiet
           -y  Yes, clobber existing files
           -+  Append to an existing file
Example:   sz file </dev/tty01 >/dev/tty01 # Send file

     XMODEM, YMODEM, and ZMODEM are  a  family  of  protocols  that  are
widely  used  is  the MS-DOS world for transferring information reliably
from one computer to another.  In all of these protocols,  a  series  of
bytes   are   sent   from  one  computer  to  the  other,  and  then  an
acknowledgement is sent back to confirm  correct  reception.   Checksums
are  used  to detect errors so that transmission is reliable even in the
face of noisy telephone lines.  Sz is a program that sends a  file  sent
from  another  computer  using  the  zmodem  protocol.   The file can be
received using rz.

     Sz uses the ZMODEM error correcting protocol to send  one  or  more
files  over a dial-in serial port to a variety of programs running under
MINIX, UNIX, MS-DOS, CP/M, VMS, and other operating systems.  It is  the
successor to XMODEM and YMODEM.

     ZMODEM greatly simplifies file transfers compared  to  XMODEM.   In
addition to a friendly user interface, ZMODEM provides Personal Computer
and other users an efficient, accurate, and robust file transfer method.

     ZMODEM  provides  complete  end-to-end   data   integrity   between
application  programs.   ZMODEM's  32  bit CRC catches errors that sneak
into even the most advanced networks.

     Output from another program may be piped to sz for transmission  by
denoting standard input with -:

        ls -l | sz -

The program output is transmitted with the filename sPID.sz where PID is
the  process ID of the sz program.  If the environment variable ONAME is
set, that is used instead.  In this case, the command:

        ls -l | ONAME=con sz -ay -


                                                                        



                                                                        


will send a  'file'  to  the  PC-DOS  console  display.  The  -y  option
instructs the receiver to open the file for writing unconditionally. The
-a option causes  the  receiver  to  convert  UNIX  newlines  to  PC-DOS
carriage returns and linefeeds.  On UNIX systems, additional information
about the file is transmitted.   If  the  receiving  program  uses  this
information,  the  transmitted  file length controls the exact number of
bytes written to the output dataset, and the modify time and  file  mode
are set accordingly.

     If sz is invoked with $SHELL set and if that variable contains  the
string  rsh  or rksh (restricted shell), sz operates in restricted mode.
Restricted mode restricts pathnames to the current directory and  PUBDIR
(usually /usr/spool/uucppublic) and/or subdirectories thereof.

     The options and flags available are:

-+
   Instruct the receiver to append transmitted data to an existing file.

-a
   Convert NL characters in the transmitted file to CR/LF.  This is done
   by the sender for XMODEM and YMODEM, by the receiver for ZMODEM.

-b
   Binary override: transfer file without any translation.

-c
   Send COMMAND (follows c) to the receiver for execution,  return  with
   COMMAND's exit status.

-d
   Change all instances of '.'  to  '/'  in  the  transmitted  pathname.
   Thus,  C.omenB0000  (which  is  unacceptable  to  MS-DOS  or CP/M) is
   transmitted as C/omenB0000.  If the resultant filename has more  than
   8  characters  in  the  stem,  a  '.' is inserted to allow a total of
   eleven.

-e
   Escape all control characters; normally XON, XOFF, DLE, CR-@-CR,  and
   Ctrl-X are escaped.

-f
   Send Full pathname.  Normally directory prefixes  are  stripped  from
   the transmitted filename.

-i
   Send COMMAND (follows  i)  to  the  receiver  for  execution,  return
   Immediately  upon the receiving program's successful reception of the
   command.

-L
   Use ZMODEM sub-packets of length n (follows L). A larger n (32  <=  n
   <= 1024) gives slightly higher throughput, a smaller one speeds error
   recovery.  The default is 128 below 300 baud, 256 above 300 baud,  or
   1024 above 2400 baud.



                                                                        



                                                                        


-l
   Wait for the receiver to acknowledge correct data every n (32 <= n <=
   1024) characters. This may be used to avoid network overrun when XOFF
   flow control is lacking.

-n
   Send  each  file  if  destination  file  does  not  exist.  Overwrite
   destination file if source file is newer than the destination file.

-N
    Send each file  if  destination  file  does  not  exist.   Overwrite
   destination  file  if  source  file  is  newer  or  longer  than  the
   destination file.

-o
   Disable automatic selection of 32 bit CRC.

-p
   Protect existing  destination  files  by  skipping  transfer  if  the
   destination file exists.

-q
   Quiet suppresses verbosity.

-r
   Resume interrupted file transfer.  If the source file is longer  than
   the  destination  file,  the  transfer commences at the offset in the
   source file that equals the length of the destination file.

-t
   Change timeout.  The timeout, in tenths of seconds, follows,  the  -t
   flag.

-u
   Unlink the file after successful transmission.

-w
   Limit the transmit window size to n bytes (n follows (enw).

-v
   Verbose causes a list of file names to be appended to /tmp/szlog.

-y
   Instruct a ZMODEM receiving program to overwrite  any  existing  file
   with the same name.

-Y
   Instruct a ZMODEM receiving program to overwrite  any  existing  file
   with  the same name, and to skip any source files that do have a file
   with the same pathname on the destination system.








                                                                        



                                                                        


Examples


     Below are some examples of the use of sz.

        sz -a d*u.c

This single command transfers all .c files in the current directory with
conversion  (-a) to end-of-line conventions appropriate to the receiving
environment.

        sz -Yan d*u.c d*u.h


Send only the .c and .h files that exist on both systems, and are  newer
on  the  sending  system than the corresponding version on the receiving
system, converting MINIX to MS-DOS text format.









































                                                                        

