Can p7zip create smaller zip files than winzip?

Question

7-Zip for Windows creates smaller zip archives than WinZip, so presumably P7zip can create smaller zip archives than Zip in Linux. So how do I create zip files using P7zip in Linux?

Answer 1

Experimentally, 7z does compress a little better than zip. I don't know how it compares with Winzip.

$ zip -q zip.zip /bin/{bash,cp,ls}
$ zip -q -9 zip9.zip /bin/{bash,cp,ls}
$ 7z a 7z.zip /bin/{bash,cp,ls} >/dev/null
$ 7z -mx=9 a 7z9.zip /bin/{bash,cp,ls} >/dev/null
$ du -ab *.zip | sort -n
550617  7z9.zip
559890  7z.zip
576161  zip9.zip
578382  zip.zip

The numeric option (-9 for zip, -mx=9 for 7z) tells the tool to spend more time to achieve a better compression ratio (it's a scale from 0 to 9).

You'll get better compression by using 7z format instead of zip format. The downside is that you need P7zip for decompression, Winzip can't handle it.

$ 7z -mx=9 a 7z9.7z /bin/{bash,cp,ls} >/dev/null 
$ 7z a 7z.7z /bin/{bash,cp,ls} >/dev/null 
$ du -ab *.7z | sort -n
471964  7z9.7z
472415  7z.7z

Install P7zip from your distribution's packages; if you have some weirdly incomplete distribution that doesn't include it, get it from upstream. There are three executables (sometimes package separately): 7zr only handles 7z archives, 7z handles many common archive formats (including zip), and 7za supports additional plugins (useful for rar, which requires non-free code that isn't linked into 7z itself). You can use the option -m to select the archive format, but usually this isn't required since the tool selects the format from the file name.