Question

I’m trying to create zip files on the fly in C++, I’m using 7-zip to try and accomplish this, specifically I want to use the 7-zip commandline (I’m willing to try and modify its source to accomplish this).

Is this possible and if so how should I go about doing it?

Answer 1

7-zip can compress from STDIN, so you start 7z process with certain command line arguments, then put your data into its STDIN. For example following:

echo foo | 7z a arc.7z -sifoo.txt
echo bar | 7z a arc.7z -sibar.txt

will create arc.7z file with two files inside: foo.txt and bar.txt (containing text foo and bar respectively).

Of course from your program you don’t need to call echo, only 7z redirecting STDIN with pipes or some other means your OS provides. And you’ll have to start 7z several times if you need to add more than one file.