Size of compressed file

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1

Hi All,

Is there is any way to find the size of compressed file without doing decompression. The size should give the original uncompressed data size

Thanks
Arun

2 
gunzip -l file.gz

will help you.

3

Depending on the tool used for compression, the above may do it, but you may also need to consider:-

zcat file.Z | wc

Robin

4

Hi.

The utility p7zip can deal with many forms of compression:

 List of supported formats:
   - Packing / unpacking: 7z, ZIP, GZIP, BZIP2, XZ and TAR
   - Unpacking only: APM, ARJ, CAB, CHM, CPIO, CramFS, DEB, DMG, FAT,
     HFS, ISO, LZH, LZMA, LZMA2, MBR, MSI, MSLZ, NSIS, NTFS, RAR (only
     if non-free p7zip-rar package is installed), RPM, SquashFS, UDF,
     VHD, WIM, XAR and Z.

For example:

$ file t1.zip 
t1.zip: Zip archive data, at least v2.0 to extract

running 7z on this file with "list" directive produces:

$ 7z l t1.zip 

7-Zip  4.58 beta  Copyright (c) 1999-2008 Igor Pavlov  2008-05-05
p7zip Version 4.58 (locale=en_US.UTF-8,Utf16=on,HugeFiles=on,1 CPU)

Listing archive: t1.zip


   Date      Time    Attr         Size   Compressed  Name
------------------- ----- ------------ ------------  ------------------------
2010-06-07 09:23:38 .....          160          126  t1.sas7bdat
------------------- ----- ------------ ------------  ------------------------
                                   160          126  1 files, 0 folders

More recent versions, around 9.x, are available in repositories (e.g Debian, SuSE, CentOS, Mac OS X ("brew"), etc).

I don't know if every compression format includes meta-data that can be extracted without uncompressing the file, but p7zip seems worth a try.

The run was in the environment:

OS, ker|rel, machine: Linux, 2.6.26-2-amd64, x86_64
Distribution        : Debian 5.0.8 (lenny, workstation)

Best wishes ... cheers, drl