# Accessing the C environment On POSIX targets, `C.environ` provides access to the process environment as a null-terminated array of C strings. The C backend declares it when generating code with or without system headers, so adding a `#include` does not change its availability. Portable `-os cross` output keeps the declaration behind a C `_WIN32` guard, allowing the same generated source to compile for POSIX or Windows. Use `os.environ()` when a V map of environment variables is sufficient.