uweohse / lrzsz Goto Github PK

zglobal.h checks HAVE_LOCALE_H, but the header is not checked in configure.ac.

Code from old website does not compile on modern C compilers. All the function definitions need the types specified in the top line. I have a huge patch file that does this and compiles the code under MacOSX as part of a fink package manager. Will this code ever be updated to handle modern (ie C99 and later) versions?

I have equipment where the YMODEM protocol is needed and this has been a workhorse for me.

I would expect that -O does not re-send "ready to receive", or whatever it's called. But I do expect it to send it once.

With -O it seems that both sender and receiver will just wait for the other to start. Seems to work with ZModem just fine.

The relevant section reads:

9.5 Segmented Streaming

If the receiver cannot overlap serial and disk I/O, it uses the
ZRINIT frame to specify a buffer length which the sender will not
overflow. The sending program sends a ZCRCW data subpacket and waits
for a ZACK header before sending the next segment of the file.

If the sending program supports reverse data stream sampling or
interrupt, error recovery will be faster (on average) than a protocol
(such as YMODEM) that sends large blocks.

A sufficiently large receiving buffer allows throughput to closely
approach that of full streaming. For example, 16kb segmented
streaming adds about 3 per cent to full streaming ZMODEM file
transfer times when the round trip delay is five seconds.

If a maximum buffer length is provided in the ZRINIT frame this is read by lsz and stored in the Rxbuflen and blklen variables, but then later when calc_blklen is called the blklen value is overridden (set to 1024) and the Rxbuflen value is never again consulted.

This is problematic for my use case because I trying to use ZMODEM to program small embedded devices which have limited RAM and a specific flash block size which must be programmed. I am trying to set the buffer length to one flash page so that I can read it in, checksum it, and then write it to flash before accepting the next subpacket.

I think the solution to this is to set the start_blklen and max_blklen variables as well when Rxbuflen is set, if it is smaller than Tframelen, exactly the same way that these are set when it is.