背景：
1.c++有DEMO_Init()、time()、add()函数。
2.而DEMO_Init()函数中又有小函数NET_DEV_Init()，小函数在.so中。
3.需要用ruby调用DEMO_Init()、time()、add()函数。
4.用的是swig工具。最后能成功调用time()、add()。
问题：
1.但是不能调用DEMO_Init(),会报错没有NET_DEV_Init()。但是NET_DEV_Init()在动态库.so文件中，我无法得知里面还有多少层小小函数啊啊，这可怎么办
不知道表述清楚没？求大神来指教我该怎么用ruby调用.so文件中的函数呢？谢谢各位了
补充：
2.c++那边的工程师确定他已经把.so文件链接好了。是不是我ruby这边也需要把c++的.so文件也链接起来？那是不是该在extconf.rb中的lib中罗列出来呢？
3.但是我罗列了c++的.so也不成功耶，还是没法调用，求教啊
4.还想请教一下Makefile中的
LIBS = $(LIBRUBYARG_SHARED) -lstdc++ -lpthread -lrt -ldl -lcrypt -lm -lc
是什么意思啊
补充：错误
irb(main):001:0> require 'demo'
=> true
irb(main):002:0> Demo.DEMO_Init
irb: symbol lookup error: /usr/local/lib/site_ruby/1.9.1/x86_64-linux/demo.so: undefined symbol: NET_DEV_Init
补充：Makefile
SHELL = /bin/sh
# V=0 quiet, V=1 verbose. other values don't work.
V = 0
Q1 = $(V:1=)
Q = $(Q1:0=@)
n=$(NULLCMD)
ECHO1 = $(V:1=@$n)
ECHO = $(ECHO1:0=@echo)
#### Start of system configuration section. ####
srcdir = .
topdir = /usr/include/ruby-1.9.1
hdrdir = /usr/include/ruby-1.9.1
arch_hdrdir = /usr/include/ruby-1.9.1/$(arch)
VPATH = $(srcdir):$(arch_hdrdir)/ruby:$(hdrdir)/ruby
prefix = $(DESTDIR)/usr
rubylibprefix = $(libdir)/$(RUBY_BASE_NAME)
exec_prefix = $(prefix)
vendorhdrdir = $(rubyhdrdir)/vendor_ruby
sitehdrdir = $(rubyhdrdir)/site_ruby
rubyhdrdir = $(includedir)/$(RUBY_BASE_NAME)-$(ruby_version)
vendordir = $(DESTDIR)/usr/lib/ruby/vendor_ruby
sitedir = $(DESTDIR)/usr/local/lib/site_ruby
ridir = $(datarootdir)/$(RI_BASE_NAME)
mandir = $(prefix)/share/man
localedir = $(datarootdir)/locale
libdir = $(exec_prefix)/lib
psdir = $(docdir)
pdfdir = $(docdir)
dvidir = $(docdir)
htmldir = $(docdir)
infodir = $(prefix)/share/info
docdir = $(datarootdir)/doc/$(PACKAGE)
oldincludedir = $(DESTDIR)/usr/include
includedir = $(prefix)/include
localstatedir = $(DESTDIR)/var
sharedstatedir = $(prefix)/com
sysconfdir = $(DESTDIR)/etc
datadir = $(datarootdir)
datarootdir = $(prefix)/share
libexecdir = $(prefix)/lib/ruby1.9.1
sbindir = $(exec_prefix)/sbin
bindir = $(exec_prefix)/bin
rubylibdir = $(rubylibprefix)/$(ruby_version)
archdir = $(rubylibdir)/$(arch)
sitelibdir = $(sitedir)/$(ruby_version)
sitearchdir = $(sitelibdir)/$(sitearch)
vendorlibdir = $(vendordir)/$(ruby_version)
vendorarchdir = $(vendorlibdir)/$(sitearch)
NULLCMD = :
CC = gcc
CXX = g++
LIBRUBY = $(LIBRUBY_SO)
LIBRUBY_A = lib$(RUBY_SO_NAME)-static.a
LIBRUBYARG_SHARED = -l$(RUBY_SO_NAME)
LIBRUBYARG_STATIC = -l$(RUBY_SO_NAME)-static
empty =
OUTFLAG = -o $(empty)
COUTFLAG = -o $(empty)
RUBY_EXTCONF_H =
cflags = $(optflags) $(debugflags) $(warnflags)
optflags = -O3
debugflags = -ggdb
warnflags = -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration
CFLAGS = -fPIC -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall -fno-strict-aliasing -fPIC $(ARCH_FLAG)
INCFLAGS = -I. -I$(arch_hdrdir) -I$(hdrdir)/ruby/backward -I$(hdrdir) -I$(srcdir)
DEFS =
CPPFLAGS = -D_FORTIFY_SOURCE=2 $(DEFS) $(cppflags)
CXXFLAGS = $(CFLAGS) -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall -fno-strict-aliasing
ldflags = -L. -Wl,-Bsymbolic-functions -Wl,-z,relro -L/build/buildd/ruby1.9.1-1.9.3.484/debian/lib -rdynamic -Wl,-export-dynamic
dldflags =
ARCH_FLAG =
DLDFLAGS = $(ldflags) $(dldflags) $(ARCH_FLAG)
LDSHARED = $(CC) -shared
LDSHAREDXX = $(CXX) -shared
AR = ar
EXEEXT =
RUBY_BASE_NAME = ruby
RUBY_INSTALL_NAME = ruby1.9.1
RUBY_SO_NAME = ruby-1.9.1
arch = x86_64-linux
sitearch = $(arch)
ruby_version = 1.9.1
ruby = /usr/bin/ruby1.9.1
RUBY = $(ruby)
RM = rm -f
RM_RF = $(RUBY) -run -e rm -- -rf
RMDIRS = rmdir --ignore-fail-on-non-empty -p
MAKEDIRS = /bin/mkdir -p
INSTALL = /usr/bin/install -c
INSTALL_PROG = $(INSTALL) -m 0755
INSTALL_DATA = $(INSTALL) -m 644
COPY = cp
TOUCH = exit >
#### End of system configuration section. ####
preload =
libpath = . $(libdir)
LIBPATH = -L. -L$(libdir)
DEFFILE =
CLEANFILES = mkmf.log
DISTCLEANFILES =
DISTCLEANDIRS =
extout =
extout_prefix =
target_prefix =
LOCAL_LIBS =
LIBS = $(LIBRUBYARG_SHARED) -lstdc++ -lpthread -lrt -ldl -lcrypt -lm -lc
SRCS = demo.cxx demo_wrap.cxx
OBJS = demo.o demo_wrap.o
TARGET = demo
TARGET_NAME = demo
TARGET_ENTRY = Init_$(TARGET_NAME)
DLLIB = $(TARGET).so
EXTSTATIC =
STATIC_LIB =
BINDIR = $(bindir)
RUBYCOMMONDIR = $(sitedir)$(target_prefix)
RUBYLIBDIR = $(sitelibdir)$(target_prefix)
RUBYARCHDIR = $(sitearchdir)$(target_prefix)
HDRDIR = $(rubyhdrdir)/ruby$(target_prefix)
ARCHHDRDIR = $(rubyhdrdir)/$(arch)/ruby$(target_prefix)
TARGET_SO = $(DLLIB)
CLEANLIBS = $(TARGET).so
CLEANOBJS = *.o *.bak
all: $(DLLIB)
static: $(STATIC_LIB)
.PHONY: all install static install-so install-rb
.PHONY: clean clean-so clean-rb
clean-static::
clean-rb-default::
clean-rb::
clean-so::
clean: clean-so clean-static clean-rb-default clean-rb
-$(Q)$(RM) $(CLEANLIBS) $(CLEANOBJS) $(CLEANFILES) .*.time
distclean-rb-default::
distclean-rb::
distclean-so::
distclean: clean distclean-so distclean-rb-default distclean-rb
@-$(RM) Makefile $(RUBY_EXTCONF_H) conftest.* mkmf.log
@-$(RM) core ruby$(EXEEXT) *~ $(DISTCLEANFILES)
@-$(RMDIRS) $(DISTCLEANDIRS) 2> /dev/null || true
realclean: distclean
install: install-so install-rb
install-so: $(RUBYARCHDIR)/$(DLLIB)
$(RUBYARCHDIR)/$(DLLIB): $(DLLIB)
-$(Q)$(MAKEDIRS) $(@D)
$(INSTALL_PROG) $(DLLIB) $(@D)
clean-static::
-$(Q)$(RM) $(STATIC_LIB)
install-rb: pre-install-rb install-rb-default
install-rb-default: pre-install-rb-default
pre-install-rb: Makefile
pre-install-rb-default: Makefile
pre-install-rb-default:
$(ECHO) installing default demo libraries
./.RUBYARCHDIR.time:
$(Q) $(MAKEDIRS) $(RUBYARCHDIR)
$(Q) $(TOUCH) $@
site-install: site-install-so site-install-rb
site-install-so: install-so
site-install-rb: install-rb
.SUFFIXES: .c .m .cc .mm .cxx .cpp .C .o
.cc.o:
$(ECHO) compiling $(<)
$(Q) $(CXX) $(INCFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(COUTFLAG)$@ -c $<
.mm.o:
$(ECHO) compiling $(<)
$(Q) $(CXX) $(INCFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(COUTFLAG)$@ -c $<
.cxx.o:
$(ECHO) compiling $(<)
$(Q) $(CXX) $(INCFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(COUTFLAG)$@ -c $<
.cpp.o:
$(ECHO) compiling $(<)
$(Q) $(CXX) $(INCFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(COUTFLAG)$@ -c $<
.C.o:
$(ECHO) compiling $(<)
$(Q) $(CXX) $(INCFLAGS) $(CPPFLAGS) $(CXXFLAGS) $(COUTFLAG)$@ -c $<
.c.o:
$(ECHO) compiling $(<)
$(Q) $(CC) $(INCFLAGS) $(CPPFLAGS) $(CFLAGS) $(COUTFLAG)$@ -c $<
.m.o:
$(ECHO) compiling $(<)
$(Q) $(CC) $(INCFLAGS) $(CPPFLAGS) $(CFLAGS) $(COUTFLAG)$@ -c $<
$(DLLIB): $(OBJS) Makefile
$(ECHO) linking shared-object $(DLLIB)
-$(Q)$(RM) $(@)
$(Q) $(LDSHAREDXX) -o $@ $(OBJS) $(LIBPATH) $(DLDFLAGS) $(LOCAL_LIBS) $(LIBS)
$(OBJS): $(hdrdir)/ruby.h $(hdrdir)/ruby/defines.h $(arch_hdrdir)/ruby/config.h
把你需要的lib 加进extconf.rb
http://www.linuxtopia.org/online_books/programming_books/ruby_tutorial/Extending_Ruby_Creating_a_Makefile_with_extconf.rb.html