I am using valgrind to check heap allocation of archive/compression tool p7zip (7zip on Windows) on Linux. I downloaded the code from here (https://sourceforge.net/projects/p7zip/files/p7zip/) and build it (make all_test) and then installed it (./install.sh).

After installation, a shell script named '7Za' is created at /usr/local/bin and its content reads as:

#! /bin/sh
"/usr/local/lib/p7zip/7za" "$@"

Also, on the specified path /usr/local/lib/p7zip/7za the executable of 7za is placed.

Now, if I run valgrind to test the memory usage of 7za (which basically runs the shell script) using this command then I get just 2KB of heap usage.

valgrind 7za x file.7z

Whereas, if I directly use the 7za binary then I get high memory usage around 1MB which also looks real one:

valgrind /usr/local/lib/p7zip/7za x /home/z/Desktop/file.7z

Similary, when I build the code, a bin directory is created there containing 7za executable. If I run it from there, then I again get high and correct memory usage.

I am trying to understand what is the difference in both approaches. Why using installed app (run through sheel script) does not give correct memory usage.