7-Zip Problem


B

BeeJ

I can't find a newsgroup for 7-Zip so I'll ask here.
Point me at a relevant newsgroup please.

I am using 7-Zip to zip a number of files.
I use the 7-Zip 7ZA.EXE that runs in the background.
I provide it with a file that contains a list of files to place into
the final output zipped file.

This all works most all the time.
The exception is when the file list contains many files or possible
some other problem.

I believe the list is good since if I supply this same list, in all
cases, big or small, to WinZip, then WinZip has no problem producing
the output zipped file only 7-Zip get stumped and quits without
finishing.

But as I said, WinZip handles the same list and 7-Zip works fine with a
shorter list.

So is there some built-in limit to the number of files or what?

Running on Win XP Pro with all the latest updates.
Have 4G RAM.

BTW the resultant WinZip file is 150 MBytes and is a combination of
compressable text and non-compressable Zip and BMP files.
 
Ad

Advertisements

C

Char Jackson

I can't find a newsgroup for 7-Zip so I'll ask here.
Point me at a relevant newsgroup please.

I am using 7-Zip to zip a number of files.
I use the 7-Zip 7ZA.EXE that runs in the background.
I provide it with a file that contains a list of files to place into
the final output zipped file.

This all works most all the time.
The exception is when the file list contains many files or possible
some other problem.

I believe the list is good since if I supply this same list, in all
cases, big or small, to WinZip, then WinZip has no problem producing
the output zipped file only 7-Zip get stumped and quits without
finishing.

Snip the troublesome list in half, feeding it to 7-Zip one half at a
time. If 7-Zip chokes on one of those files, snip it again, and so on,
until you narrow it down to the specific entry that's causing the
problem. If that test is negative, read on.

If your theory is correct that 7-Zip stumbles on large numbers of
files, that in itself should be testable and repeatable, and you
should be able to find the exact number of files that make it fall
over. With that number in mind, feed it a different list with more
than that number of files and see if it falls down the same way.
Consider that the limitation may not be the actual number of files,
but perhaps an internal limit on the length of the file path plus
filename. Test by burying a working set of files under an absurdly
long directory path and see what happens.

I don't use 7-Zip or WinZip, (I only use WinRar), but if 7-Zip has the
kind of limits that you suspect, it should be fairly straightforward
to track them down.
 
Ad

Advertisements

P

Paul

BeeJ said:
I can't find a newsgroup for 7-Zip so I'll ask here.
Point me at a relevant newsgroup please.

I am using 7-Zip to zip a number of files.
I use the 7-Zip 7ZA.EXE that runs in the background.
I provide it with a file that contains a list of files to place into the
final output zipped file.

This all works most all the time.
The exception is when the file list contains many files or possible some
other problem.

I believe the list is good since if I supply this same list, in all
cases, big or small, to WinZip, then WinZip has no problem producing the
output zipped file only 7-Zip get stumped and quits without finishing.

But as I said, WinZip handles the same list and 7-Zip works fine with a
shorter list.

So is there some built-in limit to the number of files or what?

Running on Win XP Pro with all the latest updates.
Have 4G RAM.

BTW the resultant WinZip file is 150 MBytes and is a combination of
compressable text and non-compressable Zip and BMP files.

When the program "quits", does it leave the partially completed archive
on your disk ? If it did, you could use a hex editor, scroll to the end
of the file, and see which item it got stuck on. Either the last item
shown is the one responsible for the problem, or the program never had
a chance to write out its name into the file.

There is a file "7zFormat.txt" in the lzma922.tar.bz2 SDK. It will
give you some idea about how the program is structured. If I'm reading
that pseudo-code correctly, the file names are emitted in a jumble,
all together, as the archive is being built. You could see, with your hex
editor, whether the program is still writing out filenames into the
archive file, and which file names succeeded and which didn't.

http://www.7-zip.org/sdk.html

I haven't been able to find any stated limits for the program.

Paul
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top