getting uncompressed file size from GZIPInputStream

[Jim Schlemmer]

I'm trying to figure out if there's some way to determine the
uncompressed size of a gzip'd file. Perhaps it's not knowable in
advance?

-jim

 

[Michael Borgwardt]

I'm trying to figure out if there's some way to determine the
uncompressed size of a gzip'd file. Perhaps it's not knowable in
advance?

Indeed it isn't, since gzip works on streams unlike zip, which
works on files and uses an index.

 

[Liz]

I'm trying to figure out if there's some way to determine the
uncompressed size of a gzip'd file. Perhaps it's not knowable in
advance?

-jim

C:\>gzip -l format1data.xml.gz
compressed uncompr. ratio uncompressed_name
1501 14678 89.8% format1data.xml

 

[Michael Borgwardt]

C:\>gzip -l format1data.xml.gz
compressed uncompr. ratio uncompressed_name
1501 14678 89.8% format1data.xml

I'm pretty sure that what this does is simply to uncompress the file
and look at the result, i.e. not what Jim wanted.

 

[Liz]

I'm pretty sure that what this does is simply to uncompress the file
and look at the result, i.e. not what Jim wanted.

You did not put any restrictions on HOW to do it. Are
there any other requirements like speed?

 

[Michael Borgwardt]

You did not put any restrictions on HOW to do it.

He said "Perhaps it's not knowable in advance?", which means to me
"in advance of decompressing" and suggests that he he wants just that.

 

[Josef Garvi]

He said "Perhaps it's not knowable in advance?", which means to me
"in advance of decompressing" and suggests that he he wants just that.

Like for example wanting to know if there is sufficient disk space before
decompressing a huge file.

--
Josef Garvi

"Reversing desertification through drought tolerant trees"
http://www.eden-foundation.org/

new income - better environment - more food - less poverty