Cygwin's default user interface will be the bash shell working inside the mintty terminal emulator.[25] The DLL also implements pseudo terminal (pty) gadgets, and Cygwin ships with several terminal emulators which can be determined by them, like rxvt/urxvt and xterm. The Edition of GCC that includes Cygwin has different extensions https://acgwin65420.getblogs.net/69559498/the-best-side-of-acgwin