I have stumbled on a problem with the fish shell (which is my favorite shell) when I am trying to use command substitution:
gcc (pkg-config --libs --cflags gtk+-2.0 cairo) -o drawing_widget drawing_widget.c gcc: erreur: unrecognized command line option ‘-pthread -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/pango-1.0 -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/harfbuzz -I/usr/include/freetype2 -I/usr/include/harfbuzz -I/usr/include/libdrm -I/usr/include/libpng16 -lgtk-x11-2.0 -lgdk-x11-2.0 -lpangocairo-1.0 -latk-1.0 -lgdk_pixbuf-2.0 -lgio-2.0 -lpangoft2-1.0 -lpango-1.0 -lgobject-2.0 -lglib-2.0 -lfontconfig -lfreetype -lcairo ’I have tested with both bash and zsh and the equivalent comment works:
gcc $(pkg-config --libs --cflags gtk+-2.0 cairo) -o drawing_widget drawing_widget.c