1SZ(1) General Commands Manual SZ(1)
2
6 sx, sb, sz - XMODEM, YMODEM, ZMODEM file send
7
9 sz [-+8abdefkLlNnopqTtuvyY] file ...
10 sb [-adfkqtuv] file ...
11 sx [-akqtuv] file
12 sz [-oqtv] -c COMMAND
13 sz [-oqtv] -i COMMAND
14 sz -TT
15
17 Sz uses the ZMODEM, YMODEM or XMODEM error correcting protocol to send
18 one or more files over a dial-in serial port to a variety of programs
19 running under PC-DOS, CP/M, Unix, VMS, and other operating systems.
20 While rz is smart enough to be called from cu(1), very few versions of
22 cu(1) are smart enough to allow sz to work properly. Unix flavors of
23 Professional-YAM are available for such dial-out application.
24 Sz sends one or more files with ZMODEM protocol.
27 ZMODEM greatly simplifies file transfers compared to XMODEM. In addi‐
29 tion to a friendly user interface, ZMODEM provides Personal Computer
30 and other users an efficient, accurate, and robust file transfer
31 method.
32 ZMODEM provides complete END-TO-END data integrity between application
34 programs. ZMODEM's 32 bit CRC catches errors that sneak into even the
35 most advanced networks.
36 Advanced file management features include AutoDownload (Automatic file
38 Download initiated without user intervention), Display of individual
39 and total file lengths and transmission time estimates, Crash Recovery,
40 selective file transfers, and preservation of exact file date and
41 length.
42 Output from another program may be piped to sz for transmission by
44 denoting standard input with "-":
45 ls -l | sz -
46 The program output is transmitted with the filename sPID.sz where PID
47 is the process ID of the sz program. If the environment variable ONAME
48 is set, that is used instead. In this case, the Unix command:
49 ls -l | ONAME=con sz -ay -
50 will send a "file" to the PC-DOS console display. The -y option
51 instructs the receiver to open the file for writing unconditionally.
52 The -a option causes the receiver to convert Unix newlines to PC-DOS
53 carriage returns and linefeeds.
54 Sb batch sends one or more files with YMODEM or ZMODEM protocol. The
57 initial ZMODEM initialization is not sent. When requested by the
58 receiver, sb supports YMODEM-g with "cbreak" tty mode, XON/XOFF flow
59 control, and interrupt character set to CAN (^X). YMODEM-g (Profes‐
60 sional-YAM g option) increases throughput over error free channels
61 (direct connection, X.PC, etc.) by not acknowledging each transmitted
62 sector.
63 On Unix systems, additional information about the file is transmitted.
65 If the receiving program uses this information, the transmitted file
66 length controls the exact number of bytes written to the output
67 dataset, and the modify time and file mode are set accordingly.
68 Sx sends a single file with XMODEM or XMODEM-1k protocol (sometimes
71 incorrectly called "ymodem"). The user must supply the file name to
72 both sending and receiving programs.
73 If sz is invoked with $SHELL set and iff that variable contains the
75 string rsh , rbash or rksh (restricted shell), sz operates in
76 restricted mode. Restricted mode restricts pathnames to the current
77 directory and PUBDIR (usually /usr/spool/uucppublic) and/or subdirecto‐
78 ries thereof.
79 The fourth form sends a single COMMAND to a ZMODEM receiver for execu‐
82 tion. Sz exits with the COMMAND return value. If COMMAND includes
83 spaces or characters special to the shell, it must be quoted.
84 The fifth form sends a single COMMAND to a ZMODEM receiver for execu‐
87 tion. Sz exits as soon as the receiver has correctly received the com‐
88 mand, before it is executed.
89 The sixth form (sz -TT) attempts to output all 256 code combinations to
92 the terminal. In you are having difficulty sending files, this command
93 lets you see which character codes are being eaten by the operating
94 system.
95 If sz is invoked with stdout and stderr to different datasets, Verbose
98 is set to 2, causing frame by frame progress reports to stderr. This
99 may be disabled with the q option.
100 The meanings of the available options are:
102 -+, --append
104 Instruct the receiver to append transmitted data to an existing
105 file (ZMODEM only).
106 -2, --twostop
107 use two stop bits (if possible). Do not use this unless you know
108 what you are doing.
109 -8, --try-8k
110 Try to go up to 8KB blocksize. This is incompatible with stan‐
111 dard zmodem, but a common extension in the bbs world. (ZMODEM
112 only).
113 --start-8k
114 Start with 8KB blocksize. Like --try-8k.
115 -a, --ascii
116 Convert NL characters in the transmitted file to CR/LF. This is
117 done by the sender for XMODEM and YMODEM, by the receiver for
118 ZMODEM.
119 -b, --binary
120 (ZMODEM) Binary override: transfer file without any translation.
121 -B NUMBER, --bufsize NUMBER
122 Use a readbuffer of NUMBER bytes. Default ist 16384, which
123 should be enough for most situations. If you have a slow machine
124 or a bad disk interface or suffer from other hardware problems
125 you might want to increase the buffersize. -1 or auto use a
126 buffer large enough to buffer the whole file. Be careful with
127 this option - things normally get worse, not better, if the
128 machine starts to swap.
129 Using this option turns of memory mapping of the input file.
131 This increases memory and cpu usage.
132 -c COMMAND, --command COMMAND
133 Send COMMAND to the receiver for execution, return with COM‐
134 MAND´s exit status.
135 -C N, --command-tries N
136 Retry to send command N times (default: 11).
137 -d, --dot-to-slash
138 Change all instances of "." to "/" in the transmitted pathname.
139 Thus, C.omenB0000 (which is unacceptable to MSDOS or CP/M) is
140 transmitted as C/omenB0000. If the resultant filename has more
141 than 8 characters in the stem, a "." is inserted to allow a
142 total of eleven.
143 This option enables the --full-path option.
145 --delay-startup N
146 Wait N seconds before doing anything.
147 -e, --escape
148 Escape all control characters; normally XON, XOFF, DLE, CR-@-CR,
149 and Ctrl-X are escaped.
150 Force the sender to rename the new file if a file with the same
151 name already exists.
152 -f, --full-path
153 Send Full pathname. Normally directory prefixes are stripped
154 from the transmitted filename.
155 This is also turned on with to --dot-to-slash option.
157 -h, --help
158 give help.
159 -i COMMAND, --immediate-command COMMAND
160 Send COMMAND to the receiver for execution, return immediately
161 upon the receiving program's successful recption of the command.
162 -k, --1k
163 (XMODEM/YMODEM) Send files using 1024 byte blocks rather than
164 the default 128 byte blocks. 1024 byte packets speed file
165 transfers at high bit rates. (ZMODEM streams the data for the
166 best possible throughput.)
167 -L N, --packetlen N
168 Use ZMODEM sub-packets of length N. A larger N (32 <= N <=
169 1024) gives slightly higher throughput, a smaller N speeds error
170 recovery. The default is 128 below 300 baud, 256 above 300
171 baud, or 1024 above 2400 baud.
172 -m N, --min-bps N
173 Stop transmission if BPS-Rate (Bytes Per Second) falls below N
174 for a certain time (see --min-bps-time option).
175 -M N, --min-bps-time
176 Used together with --min-bps. Default is 120 (seconds).
177 -l N, --framelen N
178 Wait for the receiver to acknowledge correct data every N (32 <=
179 N <= 1024) characters. This may be used to avoid network over‐
180 run when XOFF flow control is lacking.
181 -n, --newer
182 (ZMODEM) Send each file if destination file does not exist.
183 Overwrite destination file if source file is newer than the des‐
184 tination file.
185 -N, --newer-or-longer
186 (ZMODEM) Send each file if destination file does not exist.
187 Overwrite destination file if source file is newer or longer
188 than the destination file.
189 -o, --16-bit-crc
190 (ZMODEM) Disable automatic selection of 32 bit CRC.
191 -O, --disable-timeouts
192 Disable read timeout handling. This makes lsz hang if the other
193 side doesn't send anything, but increases performance (not much)
194 and decreases system load (reduces number of system calls by
195 about 50 percent).
196 Use this option with care.
198 -p, --protect
199 (ZMODEM) Protect existing destination files by skipping transfer
200 if the destination file exists.
201 -q, --quiet
202 Quiet suppresses verbosity.
203 -R, --restricted
204 Restricted mode: restricts pathnames to the current directory
205 and PUBDIR (usually /usr/spool/uucppublic) and/or subdirectories
206 thereof.
207 -r, --resume
208 (ZMODEM) Resume interrupted file transfer. If the source file
209 is longer than the destination file, the transfer commences at
210 the offset in the source file that equals the length of the des‐
211 tination file.
212 -s HH:MM, --stop-at HH:MM
213 Stop transmission at HH hours, MM minutes. Another variant,
214 using +N instead of HH:MM, stops transmission in N seconds.
215 -S, --timesync
216 enable timesync protocol support. See timesync.doc for further
217 information.
218 This option is incompatible with standard zmodem. Use it with
220 care.
221 --syslog[=off]
222 turn syslogging on or off. the default is set at configure time.
223 This option is ignored if no syslog support is compiled in.
224 -t TIM, --timeout TIM
225 Change timeout to TIM tenths of seconds.
226 -T, --turbo
227 Do not escape certain characters (^P, ^P|0x80, telenet escape
228 sequence [CR + @]). This improves performance by about 1 percent
229 and shouldn't hurt in the normal case (but be careful - ^P might
230 be useful if connected through a terminal server).
231 --tcp Try to initiate a TCP/IP connection. lsz will ask the receiving
232 zmodem to open a TCP/IP connection. All handshaking (which
233 address / port to use) will be done by the zmodem programs.
234 You will normally not want to use this option as lrzsz is the
236 only zmodem which understands what to do (private extension).
237 You might want to use this option if the two programs are con‐
238 nected (stdin/out) over a slow or bad (not 8bit clean) network
239 connection.
240 Use of this option imposes a security risk, somebody else could
242 connect to the port in between. See SECURITY for details.
243 --tcp-client ADDRESS:PORT
244 Act as a tcp/ip client: Connect to the given port.
245 See --tcp-server for more information.
247 --tcp-server
249 Act as a server: Open a socket, print out what to do, wait for
250 connection.
251 You will normally not want to use this option as lrzsz is the
253 only zmodem which understands what to do (private extension).
254 You might want to use this if you have to use zmodem (for which
255 reason whatever), and cannot use the --tcp option of lsz (per‐
256 haps because your telnet doesn't allow to spawn a local program
257 with stdin/stdout connected to the remote side).
258 If you use this option you have to start lsz with the --tcp-
260 client ADDRESS:PORT option. lrz will print the address and port
261 on startup.
262 Use of this option imposes a security risk, somebody else could
264 connect to the port in between. See SECURITY for details.
265 -u Unlink the file after successful transmission.
267 -U, --unrestrict
268 Turn off restricted mode (this is not possible if running under
269 a restricted shell).
270 -w N, --windowsize N
271 Limit the transmit window size to N bytes (ZMODEM).
272 -v, --verbose
273 Verbose output to stderr. More v's generate more output.
274 -X, --xmodem
275 use XMODEM protocol.
276 -y, --overwrite
277 Instruct a ZMODEM receiving program to overwrite any existing
278 file with the same name.
279 -Y, --overwrite-or-skip
280 Instruct a ZMODEM receiving program to overwrite any existing
281 file with the same name, and to skip any source files that do
282 have a file with the same pathname on the destination system.
283 --ymodem
284 use ZMODEM protocol.
285 -Z, --zmodem
286 use ZMODEM protocol.
287
289 Restricted mode restricts pathnames to the current directory and PUBDIR
290 (usually /var/spool/uucppublic) and/or subdirectories thereof, and dis‐
291 ables remote command execution.
292 Restricted mode is entered if the R option is given or if lsz detects
294 that it runs under a restricted shell or if the environment variable
295 ZMODEM_RESTRICTED is found.
296 Restricted mode can be turned of with the U option if not running under
298 a restricted shell.
299 Use of the
302 --tcp-client or --tcp-server options imposes a security risk, as
303 somebody else could connect to the port before you do it, and
304 grab your data. If there's strong demand for a more secure mode
305 i might introduce some sort of password challenge.
306
310 ZNULLS may be used to specify the number of nulls to send before a
311 ZDATA frame.
312 SHELL lsz recognizes a restricted shell if this variable includes rsh
314 or rksh
315 ZMODEM_RESTRICTED
317 lrz enters restricted mode if the variable is set.
318 TMPDIR If this environment variable is set its content is used as the
320 directory to place in the answer file to a timesync request.
321 TMP Used instead of TMPDIR if TMPDIR is not set. If neither
322 TMPDIR nor TMP is set /tmp will be used.
323
325 ZMODEM File Transfer (Unix to DSZ/ZCOMM/Professional-YAM)
326 % sz -a *.c
327 This single command transfers all .c files in the current Unix direc‐
328 tory with conversion (-a) to end of line conventions appropriate to the
329 receiving environment. With ZMODEM AutoDownload enabled, Professional-
330 YAM and ZCOMM will automatically recieve the files after performing a
331 security check.
332 % sz -Yan *.c *.h
334 Send only the .c and .h files that exist on both systems, and are newer
335 on the sending system than the corresponding version on the receiving
336 system, converting Unix to DOS text format.
337 $ sz -\Yan file1.c file2.c file3.c foo.h baz.h ®(for VMS)
338 ZMODEM Command Download (Unix to Professional-YAM)
340 cpszall:all
341 sz -c "c:;cd /yam/dist"
342 sz -ya $(YD)/*.me
343 sz -yqb y*.exe
344 sz -c "cd /yam"
345 sz -i "!insms"
346 This Makefile fragment uses sz to issue commands to Professional-YAM to
347 change current disk and directory. Next, sz transfers the .me files
348 from the $YD directory, commanding the receiver to overwrite the old
349 files and to convert from Unix end of line conventions to PC-DOS con‐
350 ventions. The third line transfers some .exe files. The fourth and
351 fifth lines command Pro-YAM to change directory and execute a PC-DOS
352 batch file insms . Since the batch file takes considerable time, the
353 -i form is used to allow sz to exit immediately.
354 XMODEM File Transfer (Unix to Crosstalk)
356 % sx -a foo.c
357 ESC
358 rx foo.c
359 The above three commands transfer a single file from Unix to a PC and
360 Crosstalk with sz translating Unix newlines to DOS CR/LF. This combi‐
361 nation is much slower and far less reliable than ZMODEM.
362
364 "Caught signal 99" indicates the program was not properly compiled,
365 refer to "bibi(99)" in rbsb.c for details.
366
368 rz(omen), ZMODEM.DOC, YMODEM.DOC, Professional-YAM, crc(omen),
369 sq(omen), todos(omen), tocpm(omen), tomac(omen), yam(omen)
370 Compile time options required for various operating systems are
372 described in the source file.
373
375 The VMS version does not support wild cards. Because of VMS DCL, upper
376 case option letters muse be represented by \ proceding the letter.
377 The current VMS version does not support XMODEM, XMODEM-1k, or YMODEM.
379 VMS C Standard I/O and RMS may interact to modify the file contents.
381
383 32 bit CRC code courtesy Gary S. Brown.
384 sz.c, crctab.c, rbsb.c, zm.c, zmodem.h Unix source files
386 sz.c, crctab.c, vrzsz.c, zm.c, zmodem.h, vmodem.h, vvmodem.c, VMS
388 source files.
389 /tmp/szlog stores debugging output (sz -vv) (szlog on VMS).
391
393 The command "sz -T file" exercises the Attn sequence error recovery by
394 commanding errors with unterminated packets. The receiving program
395 should complain five times about binary data packets being too long.
396 Each time sz is interrupted, it should send a ZDATA header followed by
397 another defective packet. If the receiver does not detect five long
398 data packets, the Attn sequence is not interrupting the sender, and the
399 Myattn string in sz.c must be modified.
400 After 5 packets, sz stops the "transfer" and prints the total number of
402 characters "sent" (Tcount). The difference between Tcount and 5120
403 represents the number of characters stored in various buffers when the
404 Attn sequence is generated.
405
407 Calling sz from most versions of cu(1) doesn't work because cu's
408 receive process fights sz for characters from the modem.
409 On at least one BSD system, sz would hang or exit when it got within a
411 few kilobytes of the end of file. Using the "-w 8192" flag fixed the
412 problem. The real cause is unknown, perhaps a bug in the kernel TTY
413 output routines.
414 Programs that do not properly implement the specified file transfer
416 protocol may cause sz to "hang" the port for a minute or two. This
417 problem is corrected by using ZCOMM, Pro-YAM, or other program with a
418 correct implementation of the specified protocol.
419 Many programs claiming to support YMODEM only support XMODEM with 1k
421 blocks, and they often don't get that quite right.
422 XMODEM transfers add up to 127 garbage bytes per file. XMODEM-1k and
424 YMODEM-1k transfers use 128 byte blocks to avoid extra padding.
425 YMODEM programs use the file length transmitted at the beginning of the
427 transfer to prune the file to the correct length; this may cause prob‐
428 lems with source files that grow during the course of the transfer.
429 This problem does not pertain to ZMODEM transfers, which preserve the
430 exact file length unconditionally.
431 Most ZMODEM options are merely passed to the receiving program; some do
433 not implement all these options.
434 Circular buffering and a ZMODEM sliding window should be used when
436 input is from pipes instead of acknowledging frames each 1024 bytes.
437 If no files can be opened, sz sends a ZMODEM command to echo a suitable
438 complaint; perhaps it should check for the presence of at least one
439 accessible file before getting hot and bothered. The test mode leaves
440 a zero length file on the receiving system.
441 A few high speed modems have a firmware bug that drops characters when
443 the direction of high speed transmissson is reversed. The environment
444 variable ZNULLS may be used to specify the number of nulls to send
445 before a ZDATA frame. Values of 101 for a 4.77 mHz PC and 124 for an
446 AT are typical.
447lrzsz-0.12b 2.6.1996 SZ(1)