PEX - Process Explorer for Linux

A Linux process explorer similar to Windows Process Explorer. Also runs on FreeBSD and Solaris.

Why

I needed a one-off tool that would show me alltogether a process tree (think of pstree, ps -ef --forest or htop) but combined with network info. In Windows I'm using (since it appeared actually) Process Explorer and did not find anything alike for *ix. Even though I am a FreeBSD and Solaris evangelist, this time it is for Debian Linux + Wayland only.

It started as AI generated code for a one-off need, then turned out to be useful enough to keep developing.

Features

• Process tree / list with per-process CPU% (per-core and total), memory, threads, user, state, executable path and command line; subtree aggregates (tree CPU/memory)
• I/O rates — per-process storage read/write bytes per second (Linux)
• Details panel for the selected process: open file handles, network connections (with async DNS/service-name resolution), threads, memory maps, environment variables, loaded libraries
• History — every refresh tick is recorded in memory (~10 min at 1 s refresh): per-process CPU (user/kernel split), memory and I/O rates plus system aggregates
  • Process popup charts show the recorded past the moment you open them
  • History – Top Consumers view (GUI): rank processes by average CPU / memory / I/O over the last 1 min / 5 min / all recorded, with trend sparklines — including processes that have already exited
  • Export everything to CSV for offline analysis
• Find open file / handle — search all processes for an open file, socket, pipe or loaded library by path substring (like Process Explorer's "Find Handle or DLL")
• Kill process or whole process tree (SIGTERM, escalate to SIGKILL), with PID-reuse guards
• Search by process name or command line, including processes under collapsed tree nodes
• Show/hide kernel threads toggle
• Single instance: launching pex again raises the existing window
• Settings (window size, view mode, panels, refresh interval) persist across runs in ~/.config/pex/pex.conf; GUI window/table layout persists via imgui.ini

Two frontends, same data layer:

• pex — GUI (Dear ImGui + GLFW + OpenGL), works on X11 and Wayland
• pexc — ncurses TUI with near feature parity (no charts); ~5 MB RSS if memory matters

Screenshots

Keys

GUI (pex)

Key	Action
Ctrl+F	Focus search box
F3 / Shift+F3	Next / previous search match
Ctrl+Shift+F	Find open file / handle
F5	Refresh now
Delete (menu)	Kill process
Arrows, PgUp/PgDn, Home/End	Navigate process list
Double-click	Process details popup with history charts

History – Top Consumers is in the View menu; CSV export is in the File menu.

TUI (pexc)

Key	Action
Up/k, Down/j, PgUp/PgDn, Home/g, End/G	Navigate
Enter/Right, Left	Expand / collapse tree node
< > (or , .), 0	Horizontal scroll, reset
Tab	Switch panel focus
1-6	Details tab by number
/, n, N	Search, next/previous match
o	Find open file / handle
d	Dump recorded history to ~/pex-history-<timestamp>-{system,processes}.csv
u	Show/hide kernel threads
x, K	Kill process / kill tree
s, c	Toggle system panel / expand per-CPU view
r / F5	Refresh now
? / F1	Help
q	Quit

Requirements

Being able to compile (C++23, CMake >= 3.20). Tested to run on:

• Debian 13, GNOME/Wayland
• Gentoo, KDE/X11
• FreeBSD 15-RELEASE, XFCE/X11
• Solaris 11.4, GNOME/X11
• Solaris, Debian, FreeBSD: terminal

Building

Linux (works)

git clone https://github.com/rezdm/pex.git && cd pex
mkdir build && cd build
cmake .. -DPEX_PLATFORM=linux
make -j$(nproc)

Other (works, but not thoroughly tested through daily usage)

  -DPEX_PLATFORM=freebsd  # FreeBSD
  -DPEX_PLATFORM=solaris  # Solaris

To build only the TUI (no X11/OpenGL needed):

cmake .. -DBUILD_GUI=OFF

FreeBSD

I am using pex in FreeBSD 15-RELEASE, with XFCE, X11 in VirtualBox 7.2. Seems to work -- shows all that I need. Note: per-process I/O byte counters and exact TCP states are not available through the FreeBSD APIs used; those columns show -/inferred values.

Solaris

I am testing pex on Solaris 11.4 CBE, with GNOME, X11 in VirtualBox 7.2. Works, but with an additional step, some workaround for libX11 limitation. libX11 itself resolves fine, but GLFW is reporting "Failed to load Xlib" likely because it can not dlopen("libX11.so.6") (hard-coded by GLFW) but my Solaris installation provides libX11.so.4. I did:

# cd pex/build...
mkdir lib
ln -s /usr/lib/64/libX11.so.4 ./lib/libX11.so.6
LD_LIBRARY_PATH=$PWD/lib ./pex

This is not correct, but at least allowes to test. To see properties of other users' processes, set up an RBAC profile and run via pfexec — see PRIVILEGES.md.

Console version

Additional functionality -- ncurses-based TUI version. Compiled by default together with GUI version. Not to build it:

... -DBUILD_TUI=OFF

The TUI also works with the system ncurses on Solaris 11.4:

cmake .. -DPEX_PLATFORM=solaris -DBUILD_GUI=OFF \
  -DCURSES_INCLUDE_DIR=/usr/include/ncurses \
  -DCURSES_LIBRARY=/usr/lib/64/libncursesw.so.6

(Mouse wheel-down needs ncurses mouse protocol v2 and is compiled out with the v1 system headers.)

Challenges in Solaris

Solaris has its own curses library that interferes with code. User should either compile/install ncurses manually or rely on this project's CMakeLists.txt to retrieve it: Compiling/installing manually, then:

rm -rf * && \
cmake ..\
  -DPEX_PLATFORM=solaris \
  -DCURSES_INCLUDE_DIR="/opt/ncurses6.6/include;/opt/ncurses6.6/include/ncursesw" \
  -DCURSES_LIBRARY=/opt/ncurses6.6/lib/libncursesw.a && \
gmake -j8 pexc

or build ncurses automatically during the build process:

cmake .. -DPEX_PLATFORM=solaris -DBUILD_NCURSES=ON

Installing

#git clone...
cd pex
mkdir build && cd build && cmake .. && make -j$(nproc)

Copy pex executable and pex.png to a folder of choice and set capabilities:

sudo setcap 'cap_sys_ptrace,cap_dac_read_search,cap_kill+ep' {path-to-executable-location}/pex

pex runs fine without this — you just won't see details (files, network, environment, ...) of other users' processes. For the full story per OS (Linux capabilities incl. a group-restricted variant, Solaris RBAC/pfexec, FreeBSD sudo/doas), see PRIVILEGES.md.

May be create .desktop file for GNOME:

[Desktop Entry]
Name=PEX
Comment=Process Explorer for Linux
Exec=pex
Icon=pex
Terminal=false
Type=Application
Categories=System;Monitor;
Keywords=process;monitor;system;task;manager;

Add this pex.desktop to ~/.local/share/applications/

For the icon to appear in app menus:

mkdir -p ~/.local/share/icons/hicolor/256x256/apps
cp {path-to-proect source}/pex.png ~/.local/share/icons/hicolor/256x256/apps/pex.png
update-desktop-database ~/.local/share/applications/

Makes sense to crop/resize original logo into destination (with ImageMagic):

convert {path-to-project-source}/pex-logo.png -gravity center -crop 800x800+0+0 +repage -resize 256x256 {path-to-installation-folder/pex.png

Ctrl+Shift+Esc, like in Windows

To start (or raise — pex is single-instance, a second launch raises the existing window) the same way as in Windows, bind a GNOME custom shortcut:

gsettings set org.gnome.settings-daemon.plugins.media-keys custom-keybindings "['/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/pex/']"
dconf write /org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/pex/name "'PEX'"
dconf write /org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/pex/command "'{path-to-executable-location}/pex'"
dconf write /org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/pex/binding "'<Control><Shift>Escape'"

Memory footprint

Most of the GUI's RSS (~150 MB) is the OpenGL/Wayland rendering stack, not pex itself (see issue #5 for measurements). If memory matters:

• use pexc (~5 MB), or
• run the GUI under XWayland: WAYLAND_DISPLAY= ./pex (saves ~50 MB by skipping libdecor/GTK client-side decorations)