Xie Weifang (xwf@shoukui.pku.edu.cn)
Tue, 3 Dec 1996 15:34:35 +0900 (JST)


I had read the /usr/src/linux/README file and the Makefile.
but there are some sentences I do not understand. the following
is what I cut from Makefile(Linux1.2.8)



CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
else if [ -x /bin/bash ]; then echo /bin/bash; \
else echo sh; fi ; fi)
TOPDIR := $(shell if [ "$$PWD" != "" ]; then echo $$PWD; else pwd; fi)

is the .EXPORT_ALL_VARIABLES a new make instruction(like .DEFAULT)?
is the "$$BASH" and other $$XXX right? or it should be "$BASH"?
what the assignment := mean?

I am sorry to ask so simple question, but I could not find useful
information by myself in my Linux(the make man page do not include
the syntax of Makefile) and Internet.

Perhaps you can tell where to find the makefile syntax of Linux.

Thank you!

Duan Zhenhai