# Linux Setup and Installation

Use a C99 compiler, C++17 compiler for the GUI, CMake 3.25+, a CMake backend, binutils and
pkg-config. The core needs only the C/math runtime. FLTK 1.4 development files
enable the GUI; JACK-compatible development files enable the optional audio/MIDI
backend. Build/test/install tooling uses Python 3.12+ (standard library only). No command starts a server, installs dependencies or changes system
settings.

```sh
cmake -S . -B build -DCMAKE_BUILD_TYPE=Debug
cmake --build build --parallel
ctest --test-dir build --output-on-failure
./build/xtc
```

Start/configure a JACK or PipeWire JACK-compatible server through your existing
system setup first. xtc opens without starting one and requires reconnect after
server loss/rate changes. In a separate JACK routing tool connect desired MIDI
to `midi_in`, audio capture to `input`, and `output`/`output_right` to
left/right playback ports. No physical routes are automatic. Input/recording
remain mono. See GUI.md, AUDIO_FILES.md, MIDI.md and MIXER.md for
composing/recording/editing.

`xtc --help` and `xtc --version` work without a display/server.
`xtc project.xtc` opens one project; no-file startup retains FLTK options such
as `-display`. `xtc-check --validate project.xtc` validates metadata only;
native graphs cannot be serialized. See RECOVERY.md before replacing damaged
files.

---

## Staged Installation

CMake installation includes the core, xtc-check, pkg-config metadata, licenses
and documentation. `XTC_INSTALL_GUI` defaults on when FLTK was found, adding the
application and desktop launcher. Use `-DXTC_INSTALL_GUI=OFF` for core-only
installation. The prefix defaults to `/usr/local`:

```sh
cmake -S . -B build -DCMAKE_INSTALL_PREFIX=/usr
cmake --build build --parallel
DESTDIR="$PWD/build/stage" cmake --install build
DESTDIR="$PWD/build/stage" cmake --build build --target uninstall
```

Review staged contents before using a package manager or choosing a writable
live prefix. For a user installation, use an absolute `CMAKE_INSTALL_PREFIX` such as
`$HOME/.local` and ensure its bin is in PATH. Prefixes containing spaces are
tested; shell metacharacters/newlines, quotes, dollar signs and backslashes are
not supported. No root installation is performed by tests. Uninstall from the
same source version and prefix: it removes only known files, keeps unrelated
files and removes directories only if empty. It is idempotent. It is not a
system package manager and cannot undo replacement of another installation.

Installed files: bin/xtc-check, optional bin/xtc, include/xtc/*.h, lib/libxtc.a,
lib/pkgconfig/xtc.pc, share/doc/xtc, share/licenses/xtc/LICENSE and optional
share/applications/xtc.desktop. No daemon, service, bundled library or MIME
registration is installed. Desktop caches are left to the packager/environment.
The launcher uses the system audio icon and can open a single file argument.

C/C++ consumers use `pkg-config --cflags --libs --static xtc` plus the chosen
compiler; expose PREFIX/lib/pkgconfig through PKG_CONFIG_PATH when needed.
Static backend consumers need JACK if that optional backend was built; the pc
file records its private dependency. Public headers contain no JACK/FLTK types.
To build without optional libraries, configure with `-DXTC_BUILD_GUI=OFF
-DXTC_WITH_JACK=OFF -DXTC_WITH_LADSPA=OFF`.
Python is not needed to run the installed executables or library.

---

## Binary/Development Archive

`cmake --build build --target package-binary` creates a system-linked Linux archive plus SHA-256 sidecar below
the selected binary directory; `cmake --build build --target test-package` verifies its contents. It includes usr/bin,
headers/static library/pkg-config metadata, desktop file (when FLTK is present),
manuals, baseline and MIT license. No shared library, third-party plugin, media,
service or dependency installer is bundled. `BINARY_MANIFEST.json` lists file
hashes/sizes, architecture/libc and ELF NEEDED libraries. The entire archive's
hash covers the manifest too. Do not assume compatibility with another
distribution.

Inspect/test under a temporary directory first. For a writable user prefix,
extract the archive with two leading path components stripped
(`xtc-VERSION-linux- ARCH/usr`), placing bin/include/lib/share directly under
that prefix. Put its bin on PATH and lib/pkgconfig on PKG_CONFIG_PATH. The
archive's pkg-config prefix is relative to its installed location; normal
`cmake --build build --target install` retains its configured prefix. Use the matching source's uninstall with
that prefix, or review the manifest before removing its files. Unknown/unrelated
files are retained by source uninstall. This local tar package is not a
pacman/RPM/deb registration or public distribution.

`xtc-check --diagnose` reports build capabilities and format/engine limits
without opening a server or executing a plugin. `xtc --diagnose` works
headlessly as well. Missing runtime GUI libraries are loader errors: install the
distribution's compatible dependencies or rebuild the core-only configuration.
Build without optional libraries using a fresh directory,
`cmake -S . -B build/minimal -DXTC_BUILD_GUI=OFF -DXTC_WITH_JACK=OFF -DXTC_WITH_LADSPA=OFF`. No system
setting or package is changed by tests.