Guix

This package uses the (La)TeX extension -shell-escape to establish whether the document is being processed on a Windows or on a Unix-like system, or on Cygwin (Unix environment over a Windows system). Booleans provided are: \ifwindows, \iflinux, \ifmacosx and \ifcygwin. The package also preserves the output of uname on a Unix-like system, which may be used to distinguish between various classes of systems.