By decide do you mean how do you tell zip to compress faster or better?
If you want zip to compress faster you use -1 at the command line. To
compress better, you use -9.
If you're asking how you decide whether to use -1 or -9, it would depend
on how much disk space you have.
On 03/26/2015 11:07 AM, Joe Quinn wrote:
How do you decide between speed and compression in doing zip files in OS X?
Sent from my iPhone
On Mar 26, 2015, at 10:50 AM, Todor Fassl <fassl....@gmail.com> wrote:
There are theoretical limits to the amount of compression you can get without
loss of information although different compression algorithms would work better
or worse depending on the stuff you are compressing. The OP said he wanted his
stuff compressed as small as humanly possible but that would depend on his
stuff. But zip, which is part of Mac OS,has a parameter for whether you want
more speed or more compression. I doubt any other utility can do a lot better
than zip. Like I said, there are theoretical limits to how much compression you
can get so I doubt you'll get more than a few percent smaller files with some
other tool.
Note: If you try to compress an already compressed file, like an mp3, it will
probably get bigger.
On 03/26/2015 10:26 AM, 'Chris Blouch' via MacVisionaries wrote:
I compressed my copy of Keynote, which is really made up of thousands of files
under the hood totaling 611,951,069 bytes (692.5 MB). To test unix compress I
did
tar -zcvf test.gz /Applications/Keynote.app/
which generated a compressed file of 428,440,218 bytes (428.4MB) or about 61.9%
of the original file size. Doing the same thing through the finder I selected
Keynote and then chose Compress from the File menu. That generated a zip file
of 453,379,578 butes (453.4 MB) or 65.5%. Just for the fun of it I also tried
doing a 7-Zip. Downloaded a 7-Zip app for OSX from here:
http://www.updatestar.com/directdownload/7zx/2188433
which generated a .7z file of 375,098,819 bytes (375.1MB) or about 54%. So it
looks like 7-zip is the smallest (11% smaller than plain zip in my test) but
the downside is that it's not very popular. If you send this to someone else
they will have to go through the bother of finding, downloading and installing
an app to uncompressed it. Pretty much everyone can handle a zip file without
much trouble.
As with all compression, the results are also based on what you are
compressing. Text, which has lots of repeating patterns, compresses really
well. Binary files such as audio, video and images might not compress at all.
CB
On 3/25/15 7:38 PM, Joe Quinn wrote:
now that SArchiver’s gone down the tubes? what’s the best archiving utility for
the mac? i wanna be able to compress files as small as humanly possible, but
still retain quality. thanks for any info!
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