$ gcc prog.c -o prog `gtk-config --cflags` `gtk-config --libs` bash: gtk-config: command not found bash: gtk-config: command not found prog.c:1:21: gtk/gtk.h: No such file or directory prog.c: Infunction `main': prog.c:6: error: `GtkWidget' undeclared (first use in this function) ・・・以下省略