PEX - Process Explorer for Linux

A Linux process explorer similar to Windows Process Explorer. Also runs on FreeBSD and Solaris, with experimental support on macOS (Metal GUI + TUI) and TUI-only on Windows.

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
Difference highlighting (Process Explorer style) — new processes flash green, exited processes linger as red ghost rows for one refresh interval. In the GUI the ghost stays in place (under its parent in tree view, in sorted position in list view); the TUI pins ghosts to the bottom of the process panel so they are visible regardless of scroll. Toggle in the GUI View menu (diff_highlight setting)
Process churn from the kernel — with the event feed active (Linux proc connector, needs cap_net_admin, see PRIVILEGES.md; FreeBSD/macOS kqueue EVFILT_PROC), the system panel counts forks/execs/exits per tick, including short-lived processes that live and die between refreshes — the ones polling never sees
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 on X11/Wayland and Metal on macOS
pexc — ncurses TUI with near feature parity (no charts); ~5 MB RSS if memory matters

Screenshots

GUI running on macOS (Metal renderer, Apple Silicon):

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
macOS: GUI (Metal) + terminal, experimental — see below
Windows 10/11: terminal only (pexc.exe), experimental — see below

Continuous integration

Every push and pull request builds across a matrix that varies OS, compiler and C library (see .github/workflows/cmake-multi-platform.yml):

Job	Covers
Ubuntu (latest)	GCC / glibc — primary Linux build (GUI + TUI)
Debian (latest)	GCC / glibc — Debian container
Windows (TUI only)	native `windows-latest` runner; MSYS2/UCRT64 + PDCursesMod, `pexc.exe` only
macOS (Metal GUI + TUI)	native `macos-latest` runner; Apple clang/libc++, GUI over Metal + `pexc`
Ubuntu (clang)	Clang instead of GCC — catches GCC-isms and a different warning set
GCC 13 (C++23 floor)	pins the minimum toolchain (libstdc++ `std::format` landed in GCC 13.1)
Sanitizers (ASan+UBSan)	core + unit tests under Address/UndefinedBehavior sanitizers
Alpine (musl, TUI)	musl libc portability — TUI + core, GL stack skipped
FreeBSD (latest)	native build + tests in a FreeBSD VM
Solaris x86 (latest)	native build + tests in a Solaris VM

Every job builds the binaries and runs the unit tests; a separate CodeQL workflow runs static analysis. GCC 13 is the minimum supported compiler.

Building

The build type defaults to Release; pass -DCMAKE_BUILD_TYPE=Debug for a debug build.

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

Windows (experimental, TUI only)

Only the terminal app (pexc.exe) is built on Windows; the GUI is not. Curses comes from PDCursesMod (WinCon backend), fetched automatically. Build in an MSYS2 UCRT64 shell (pacman -S mingw-w64-ucrt-x86_64-gcc mingw-w64-ucrt-x86_64-cmake mingw-w64-ucrt-x86_64-ninja):

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build

Notes:

Run under Windows Terminal rather than the legacy console for much better redraw performance.
The Details panel (open files, memory maps, environment) reads other processes via the native API; some data for elevated processes needs pexc to run as Administrator.
Per-process state (all shown as Running) and thread stack traces are not available on Windows.

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

cmake .. -DBUILD_GUI=OFF

macOS (experimental)

Both apps build with the Xcode command-line tools (xcode-select --install) and CMake. The platform is auto-detected (Darwin → macos); no -DPEX_PLATFORM needed:

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j$(sysctl -n hw.ncpu)

This produces pex (GUI) and pexc (TUI). Because OpenGL is deprecated on macOS, the GUI renders through Metal (GLFW window + CAMetalLayer, imgui_impl_metal); everything above the renderer seam is the same shared ImGui UI as the other platforms. Process data comes from libproc + Mach + sysctl.

Notes:

Data for your own processes is complete without privileges; other users' file/network/env/maps details and KERN_PROCARGS2 argv/env need sudo.
SIP + the hardened runtime/AMFI block task_for_pid unless the binary carries a debugger entitlement — sudo does not help. So per-thread stack traces are unavailable on macOS regardless of privilege (would need code-signing pex with a debugger entitlement), and some system-daemon details stay hidden even as root. pex reads everything else via libproc and degrades gracefully. See PRIVILEGES.md.

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,cap_net_admin+ep' {path-to-executable-location}/pex

pex runs fine without this — you just won't see details (files, network, environment, ...) of other users' processes, and the churn line stays hidden. cap_kill (kill others' processes) and cap_net_admin (kernel process-event feed) are optional — drop them if unwanted. For the full story per OS (Linux capabilities incl. a group-restricted variant, Solaris RBAC/pfexec, FreeBSD sudo/doas, macOS sudo + SIP caveats), 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)

Name		Name	Last commit message	Last commit date
Latest commit History 181 Commits
.github/workflows		.github/workflows
cmake		cmake
src		src
tests		tests
.gitignore		.gitignore
00-claude-code-review.md		00-claude-code-review.md
10-claude-work-done.md		10-claude-work-done.md
CMakeLists.txt		CMakeLists.txt
LICENSE		LICENSE
PRIVILEGES.md		PRIVILEGES.md
README.md		README.md
TODO.md		TODO.md
pex-macos.jpeg		pex-macos.jpeg
pex-screenshot.png		pex-screenshot.png
pex.desktop		pex.desktop
pexc-screenshot.png		pexc-screenshot.png

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PEX - Process Explorer for Linux

Why

Features

Screenshots

Keys

GUI (pex)

TUI (pexc)

Requirements

Continuous integration

Building

Linux (works)

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

Windows (experimental, TUI only)

macOS (experimental)

FreeBSD

Solaris

Console version

Challenges in Solaris

Installing

Ctrl+Shift+Esc, like in Windows

Memory footprint

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PEX - Process Explorer for Linux

Why

Features

Screenshots

Keys

GUI (pex)

TUI (pexc)

Requirements

Continuous integration

Building

Linux (works)

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

Windows (experimental, TUI only)

macOS (experimental)

FreeBSD

Solaris

Console version

Challenges in Solaris

Installing

Ctrl+Shift+Esc, like in Windows

Memory footprint

About

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