Built-in variables

Variables

In build recipes:

• in, or {^} in strings: Input files (the result of the from statement)
• out, or {@} in strings: Output files (the path of the actual file being built by the recipe).
• depfile: If the recipe has a depfile statement, this is the evaluated path to the depfile.
• % or {%} in strings: The stem of the matched pattern, if a pattern is in scope and that pattern contains a %. When defining patterns in a scope where another pattern is already present, the interpolated {%} may be used to unambiguously refer to the stem of the "outer" pattern.

Global constants

These variables are valid in all scopes.

• ROOT: The abstract or filesystem path to the project root, which is always /. When interpolated as <ROOT>, this becomes the filesystem path to the directory containing the Werkfile.
• OS: Lowercase name of the host operating system.
  • Windows: windows
  • macOS: macos
  • Linux: linux
  • FreeBSD: freebsd
  • DragonFly: dragonfly
  • OpenBSD: openbsd
  • NetBSD: netbsd
  • WebAssembly (WASIp2): wasm-wasi
• OS_FAMILY: Classification of the host operating system.
  • Windows: windows
  • Linux, macOS, and BSDs: unix
  • WebAssembly (WASIp2): wasm
• ARCH: Name of the host architecture.
  • x86_64 / x64: x86_64
  • x86: x86
  • ARM (64-bit): aarch64
  • ARM (32-bit): arm
  • WebAssembly: wasm
• ARCH_FAMILY: Classification of the host architecture.
  • x86, x86_64: x86
  • ARM: arm
  • WebAssembly: wasm
• EXE_SUFFIX:
  • Windows: .exe
  • Other: empty
• DYLIB_PREFIX:
  • Windows: empty
  • Linux and macOS: lib
• DYLIB_SUFFIX:
  • Windows: .dll
  • Linux: .so
  • macOS: .dylib
• STATICLIB_PREFIX:
  • Windows: empty
  • Linux and macOS: lib
• STATICLIB_SUFFIX:
  • Windows: .lib
  • Linux and macOS: .a
• EMPTY: Always the empty string
• COLOR: When color output is enabled for werk, this is set to "1". This may be used to conditionally pass command-line arguments to compilers that don't respect the conventional CLICOLOR environment variables.