Unzipping a uint8 array

Goodmorning sirs,

I am accessing with 'webread' to a zip file located on a webserver. This zip file contains few tens of xml files. The webread function returns an array of uint8 (ascii code of the zip file I guess). Is there any method to unzip it directly on the workspace?

Thanks in advance for the support.

Answer 1

[ANKUR KUMAR]

Use unzip(zipfilename) unzip(zipfilename,directory)

Reference: http://matlab.izmiran.ru/help/techdoc/ref/unzip.html

[Stephen23]

Marco Rossi's "Answer" moved here:

well, unzip(webread('www....')) does not seem to work, since webread returns an array of uint8. Is there a way to unzip a uint8 array (corresponding to the ascii of a zip file) without creating the physical zip file?

Answer 2

[Walter Roberson]

There are Java based methods to unzip from memory streams. MATLAB's unzip uses some of the relevant methods and you can also see them in how readtable works on xlsx files.

However, it does not make complete sense to unzip an XML into the workspace. Are you looking for it to be converted to a character vector or for it to be parsed into data?

[Stephen23]

Marco Rossi's "Answer" moved here:

I am mostly interested in getting the xml string for the moment (maybe a single string merging the content of all the files). I am trying to look at the java libraries used by Matlab to unzip, but it seems to be not so straightforward.

Answer 3

[Sean de Wolski]

Use websave instead:

tempzipname = [tempname '.zip']
websave(tempzipname, url);
deleter = onCleanup(@()delete(tempzipname));
unzip(tempzipname)

You can also use tempname to generate a folder to unzip to, and then xmlread or fileread to read it in.

[Marc Youcef]

I think this was not what the author was asking in the first time. He (and me as well) - We are looking for a way to unzip to ram without using file system for decompression.

I found some info here https://undocumentedmatlab.com/blog/savezip-utility but could not get an implementation out of it. If anyone has an idea please share.

Would be great to have an evolved version of unzip function which takes a byte array as input and byte array output.

[Sean de Wolski]

Marc, that seems like a fair enhancement request. I put an enhancement in to development for it.