print_shared_pages.py

import re, pathlib, collections, shlex
shared_paths = {}
for proc_dir in pathlib.Path("/proc").iterdir():
    if re.match("[0-9]+", proc_dir.name) and (proc_dir / "maps").exists():
        try:
            map_text = (proc_dir / "maps").read_text()
        except PermissionError:
            pass
        else:
            # yay, the read_text succeeded
            proc_name = shlex.join((proc_dir / "cmdline").read_text().split("\x00"))
            this_shared_paths = set()
            for line in map_text.strip().split("\n"):
                m = re.match("([a-z0-9]+)-([a-z0-9]+) +([a-z-]{4}) +([0-9a-z]+) +([0-9a-z]+):([0-9a-z]+) +([0-9]+) +([^ ].+|)", line)
                if m is not None:
                    addr_begin, addr_end, mode, offset, major, minor, inode, path = m.groups()
                    path = path.partition(" ")[0]
                    if mode[3] == "s":
                        shared_paths.setdefault(path, set()).add(proc_name)
                elif line.strip():
                    print("Failed to parse:", line)
k = 10
print("printing top", k, "shared libraries")
for path in sorted(shared_paths, key=lambda path: len(shared_paths[path]), reverse=True)[:k]:
    processes = shared_paths[path]
    print(path, "is used by", len(processes), "processes")
    for process in processes:
        print("  ", process)
    print()