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Uncompress .DCX_AXPEXE files under VMS Integrity?

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David R. Lennon
Valued Contributor

Uncompress .DCX_AXPEXE files under VMS Integrity?



I was wondering if anyone has developed a program to uncompress .DCX_AXPEXE and/or .DCX_VAXEXE compressed files on OpenVMS Integrity? These were created with the FTSV (File Transfer Tools for DECnet Networks) utility on OpenVMS Alpha or VAX. Our site is all Itanium and would like a way to work with these files natively.


The DCX$* utility routines are available and I did find where someone expanded on the examples in the manual to make their own compress/decompress programs from them - http://www.eight-cubed.com/downloads.html#dcx but these did not work on files encoded with FTSV.


I tried taking the FTSV utility from the Freeware v7 collection and AESTing it - it seemed to translate okay but when I

try to use the SPOOL DECOMPRESS command it gives the error - %FTSV-W-NOCMPMETH, no compression methods found


I understand that these .DCX_*EXE files are self-extracting executables that can only be run under the correct system type, I am only looking to uncompress the "payload" with another program and not create a self-extracting executable for another or for VMS on Integrity. I could also see this as being useful from a security point of view, that an external (trusted?) program is doing the unpacking, not the transferred file, itself. I do realized that this DCX compression is not the best and ZIP would be a better replacement moving forward.


Other than transferring them to another architecture, has anyone been successful with unpacking these on IA64?





Honored Contributor

Re: Uncompress .DCX_AXPEXE files under VMS Integrity?

Find the end of the DCX executable image that's prefixed onto the file and hack it off, then decompress the rest of the file using the Itanium decompression.  


From dim memory...  I was in the midst of reworking FTSV and FTSO in 2006, and it worked for what it did, but it was rather old code and the compilers were reporting latent bugs and errors.   From what I saw of the code, it might not translate all that well — it had some interesting dependencies.   IIRC, it worked by compressing the file, then prefixing a decompression image onto the front.  Not all that different from how the unzip SFX stuff works.


I'm not aware of a cross-architecture decompressor.   zip and unzip allow that, but FTSV and FTSO did not.


Other options...  scrounge an Alpha and DCX there.


If you've an HP support contract, ask them for help.


Or contact me offline and I can decompress it on an Alpha here.