1RZ(1) General Commands Manual RZ(1)
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6 rx, rb, rz - XMODEM, YMODEM, ZMODEM (Batch) file receive
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9 rz [- +8abeOpqRtTuUvy]
10 rb [- +abqRtuUvy]
11 rx [- abceqRtuUv] file
12 [-][v]rzCOMMAND
13
15 This program uses error correcting protocols to receive files over a
16 dial-in serial port from a variety of programs running under PC-DOS,
17 CP/M, Unix, and other operating systems. It is invoked from a shell
18 prompt manually, or automatically as a result of an "sz file ..." com‐
19 mand given to the calling program.
20 While rz is smart enough to be called from cu(1), very few versions of
22 cu(1) are smart enough to allow rz to work properly. Unix flavors of
23 Professional-YAM are available for such dial-out application.
24 Rz (Receive ZMODEM) receives files with the ZMODEM batch protocol.
27 Pathnames are supplied by the sending program, and directories are made
28 if necessary (and possible). Normally, the "rz" command is automati‐
29 cally issued by the calling ZMODEM program, but some defective ZMODEM
30 implementations may require starting rz the old fashioned way.
31 Rb receives file(s) with YMODEM, accepting either standard 128 byte
34 sectors or 1024 byte sectors (YAM sb -k option). The user should
35 determine when the 1024 byte block length actually improves throughput
36 without causing lost data or even system crashes.
37 If True YMODEM (Omen Technology trademark) file information (file
39 length, etc.) is received, the file length controls the number of
40 bytes written to the output dataset, and the modify time and file mode
41 (iff non zero) are set accordingly.
42 If no True YMODEM file information is received, slashes in the pathname
44 are changed to underscore, and any trailing period in the pathname is
45 eliminated. This conversion is useful for files received from CP/M
46 systems. With YMODEM, each file name is converted to lower case unless
47 it contains one or more lower case letters.
48 Rx receives a single file with XMODEM or XMODEM-1k protocol. The user
51 should determine when the 1024 byte block length actually improves
52 throughput without causing problems. The user must supply the file
53 name to both sending and receiving programs. Up to 1023 garbage char‐
54 acters may be added to the received file.
55 Rz may be invoked as rzCOMMAND (with an optional leading - as generated
58 by login(1)). For each received file, rz will pipe the file to ``COM‐
59 MAND filename'' where filename is the name of the transmitted file with
60 the file contents as standard input.
61 Each file transfer is acknowledged when COMMAND exits with 0 status. A
63 non zero exit status terminates transfers.
64 A typical use for this form is rzrmail which calls rmail(1) to post
66 mail to the user specified by the transmitted file name. For example,
67 sending the file "caf" from a PC-DOS system to rzrmail on a Unix system
68 would result in the contents of the DOS file "caf" being mailed to user
69 "caf".
70 On some Unix systems, the login directory must contain a link to COM‐
72 MAND as login sets SHELL=rsh which disallows absolute pathnames. If
73 invoked with a leading ``v'', rz will be verbose (see v option). The
74 following entry works for Unix SYS III/V:
75 rzrmail::5:1::/bin:/usr/local/rzrmail
76 If the SHELL environment variable includes rsh , rbash or rksh
77 (restricted shell), rz will not accept absolute pathnames or references
78 to a parent directory, will not modify an existing file, and removes
79 any files received in error.
80 If rz is invoked with stdout and stderr to different datasets, Verbose
82 is set to 2, causing frame by frame progress reports to stderr. This
83 may be disabled with the q option.
84
87 The meanings of the available options are:
88 -+, --append
90 append received data to an existing file (ZMODEM, ASCII only).
91 -a, --ascii
92 Convert files to Unix conventions by stripping carriage returns
93 and all characters beginning with the first Control Z (CP/M end
94 of file).
95 -b, --binary
96 Binary (tell it like it is) file transfer override.
97 -B NUMBER, --bufsize NUMBER
98 Buffer NUMBER bytes before writing to disk. Default ist 32768,
99 which should be enough for most situations. If you have a slow
100 machine or a bad disk interface or suffer from other hardware
101 problems you might want to increase the buffersize. -1 or auto
102 use a buffer large enough to buffer the whole file. Be careful
103 with this options - things normally get worse, not better, if
104 the machine starts to swap.
105 -c, --with-crc
106 XMODEM only. Use 16 bit CRC (normally a one byte checksum is
107 used).
108 -C, --allow-remote-commands
109 allow remote command execution ( insecure ). This allows the
110 sender to execute an arbitrary command through system () or
111 execl (). Default is to disable this feature (?). This option is
112 ignored if running in restricted mode.
113 -D, --null
114 Output file data to /dev/null; for testing. (Unix only)
115 --delay-startup N
116 Wait N seconds before doing anything.
117 -e, --escape
118 Force sender to escape all control characters; normally XON,
119 XOFF, DLE, CR-@-CR, and Ctrl-X are escaped.
120 -E, --rename
121 Rename incoming file if target filename already exists. The new
122 file name will have a dot and a number (0..999) appended.
123 -h, --help
124 give help screen.
125 -m N, --min-bps N
126 Stop transmission if BPS-Rate (Bytes Per Second) falls below N
127 for a certain time (see --min-bps-time option).
128 -M N, --min-bps-time
129 Used together with --min-bps. Default is 120 (seconds).
130 -O, --disable-timeouts
131 Disable read timeout handling code. This makes lrz hang if the
132 sender does not send any more, but increases performance (a bit)
133 and decreases system load (through reducing the number of system
134 calls by about 50 percent).
135 Use this option with care.
137 --o-sync
138 Open output files in synchronous write mode. This may be useful
139 if you experience errors due to lost interrupts if update (or
140 bdflush or whoever this daemon is called on your system) writes
141 the buffers to the disk.
142 This option is ignored and a warning is printed if your systems
144 doesn't support O_SYNC.
145 -p, --protect
146 (ZMODEM) Protect: skip file if destination file exists.
147 -q, --quiet
148 Quiet suppresses verbosity.
149 -r, --resume
150 Crash recovery mode. lrz tries to resume interrupted file trans‐
151 fers.
152 -R, --restricted
153 Enter more restricted mode. lrz will not create directories or
154 files with a leading dot if this option is given twice.
155 See SECURITY for mode information about restricted mode.
157 -s HH:MM, --stop-at HH:MM
158 Stop transmission at HH hours, MM minutes. Another variant,
159 using +N instead of HH:MM, stops transmission in N seconds.
160 -S, --timesync
161 Request timesync packet from the sender. The sender sends its
162 system time, causing lrz to complain about more then 60 seconds
163 difference.
164 Lrz tries to set the local system time to the remote time if
166 this option is given twice (this fails if lrz is not run by
167 root).
168 This option makes lrz incompatible with certain other ZModems.
170 Don't use it unless you know what you are doing.
171 --syslog[=off]
172 turn syslogging on or off. the default is set at configure time.
173 This option is ignored if no syslog support is compiled in.
174 -t TIM, --timeout TIM
175 Change timeout to TIM tenths of seconds. This is ignored if
176 timeout handling is turned of through the O option.
177 --tcp-client ADDRESS:PORT
178 Act as a tcp/ip client: Connect to the given port.
179 See --tcp-server for more information.
181 --tcp-server
183 Act as a server: Open a socket, print out what to do, wait for
184 connection.
185 You will normally not want to use this option as lrzsz is the
187 only zmodem which understands what to do (private extension).
188 You might want to use this if you have to use zmodem (for which
189 reason whatever), and cannot use the --tcp option of lsz (per‐
190 haps because your telnet doesn't allow to spawn a local program
191 with stdin/stdout connected to the remote side).
192 If you use this option you have to start lsz with the --tcp-
194 client ADDRESS:PORT option. lrz will print the address and port
195 on startup.
196 Use of this option imposes a security risk, somebody else could
198 connect to the port in between. See SECURITY for details.
199 -U, --unrestrict
200 turn off restricted mode (this is not possible if running under
201 a restricted shell).
202 --version
203 prints out version number.
204 -v, --verbose
205 Verbose causes a list of file names to be appended to stderr.
206 More v's generate more output.
207 -wN, --windowsize N
208 Set window size to N.
209 -X, --xmodem
210 use XMODEM protocol.
211 -y, --overwrite
212 Yes, clobber any existing files with the same name.
213 --ymodem
214 use YMODEM protocol.
215 -Z, --zmodem
216 use ZMODEM protocol.
217
219 Contrary to the original ZMODEM lrz defaults to restricted mode. In
220 restricted mode lrz will not accept absolute pathnames or references to
221 a parent directory, will not modify an existing file, and removes any
222 files received in error. Remote command execution is disabled.
223 To use a more restricted mode set the environment variable ZMO‐
225 DEM_RESTRICTED or give the R option. This disables creation of subdi‐
226 rectories and invisible files.
227 Restricted mode may be turned off with the U option, unless lrz runs
229 under a restricted shell.
230 Use of the
233 --tcp-client or --tcp-server options imposes a security risk, as
234 somebody else could connect to the port before you do it, and
235 grab your data. If there's strong demand for a more secure mode
236 i might introduce some sort of password challenge.
237
240 lrz uses the following environment variables:
241 SHELL lrz recognizes a restricted shell if this variable includes rsh
243 or rksh
244 ZMODEM_RESTRICTED
246 lrz enters the more restricted mode if the variable is set.
247
249(Pro-YAM command)
251Pro-YAM Command: sz *.h *.c
252(This automatically invokes rz on the connected system.)
253
255 ZMODEM.DOC, YMODEM.DOC, Professional-YAM, crc(omen), sz(omen),
256 usq(omen), undos(omen)
257 Compile time options required for various operating systems are
259 described in the source file.
260
262 Sending serial data to timesharing minicomputers at sustained high
263 speeds has been known to cause lockups, system halts, kernel panics,
264 and occasional antisocial behaviour. When experimenting with high
265 speed input to a system, consider rebooting the system if the file
266 transfers are not successful, especially if the personality of the sys‐
267 tem appears altered.
268 The Unix "ulimit" parameter must be set high enough to permit large
270 file transfers.
271 The TTY input buffering on some systems may not allow long blocks or
273 streaming input at high speed. You should suspect this problem when
274 you can't send data to the Unix system at high speeds using ZMODEM,
275 YMODEM-1k or XMODEM-1k, when YMODEM with 128 byte blocks works prop‐
276 erly. If the system's tty line handling is really broken, the serial
277 port or the entire system may not survive the onslaught of long bursts
278 of high speed data.
279 The DSZ or Pro-YAM zmodem l numeric parameter may be set to a value
281 between 64 and 1024 to limit the burst length ("zmodem pl128").
282 32 bit CRC code courtesy Gary S. Brown. Directory creation code from
284 John Gilmore's PD TAR program.
285
287 Calling rz from most versions of cu(1) doesn't work because cu's
288 receive process fights rz for characters from the modem.
289 Programs that do not properly implement the specified file transfer
291 protocol may cause sz to "hang" the port for a minute or two. Every
292 reported instance of this problem has been corrected by using ZCOMM,
293 Pro-YAM, or other program with a correct implementation of the speci‐
294 fied protocol.
295 Many programs claiming to support YMODEM only support XMODEM with 1k
297 blocks, and they often don't get that quite right.
298 Pathnames are restricted to 127 characters. In XMODEM single file
300 mode, the pathname given on the command line is still processed as
301 described above. The ASCII option´s CR/LF to NL translation merely
302 deletes CR´s; undos(omen) performs a more intelligent translation.
303
305 The VMS version does not set the file time.
306 VMS C Standard I/O and RMS may interact to modify file contents unex‐
308 pectedly.
309 The VMS version does not support invocation as rzCOMMAND . The current
311 VMS version does not support XMODEM, XMODEM-1k, or YMODEM.
312 According to the VMS documentation, the buffered input routine used on
314 the VMS version of rz introduces a delay of up to one second for each
315 protocol transaction. This delay may be significant for very short
316 files. Removing the "#define BUFREAD" line from rz.c will eliminate
317 this delay at the expense of increased CPU utilization.
318 The VMS version causes DCL to generate a random off the wall error mes‐
320 sage under some error conditions; this is a result of the incompatibil‐
321 ity of the VMS "exit" function with the Unix/MSDOS standard.
322
324 Rz supports incoming ZMODEM binary (-b), ASCII (-a), protect (-p),
325 clobber (-y), and append (-+) requests. The default is protect (-p)
326 and binary (-b).
327 The Unix versions support ZMODEM command execution.
329
331 rz.c, crctab.c, rbsb.c, zm.c, zmodem.h Unix source files.
332 rz.c, crctab.c, vrzsz.c, zm.c, zmodem.h, vmodem.h, vvmodem.c, VMS
334 source files.
335 OMEN RZ(1)