Debian-specific modifications to the upstream Makefile.in to
build a shared library.
---
 Makefile.in  |   45 ++++++++++++++++++++++++++++++++++++++++++---
 configure    |    2 +-
 configure.in |    2 +-
 3 files changed, 44 insertions(+), 5 deletions(-)

--- a/Makefile.in
+++ b/Makefile.in
@@ -40,6 +40,14 @@ mandir = @mandir@
 srcdir = @srcdir@
 VPATH = @srcdir@
 
+# some defines for shared library compilation
+MAJ=1.0
+LIBVERSION=$(MAJ).0
+LIBNAME=pcap
+LIBRARY=lib$(LIBNAME).a
+SOLIBRARY=lib$(LIBNAME).so
+SHAREDLIB=$(SOLIBRARY).$(LIBVERSION)
+
 #
 # You shouldn't need to edit anything below.
 #
@@ -56,6 +64,7 @@ PROG=libpcap
 
 # Standard CFLAGS
 CFLAGS = $(CCOPT) $(INCLS) $(DEFS)
+CFLAGS_SHARED = -shared -Wl,-soname,$(SOLIBRARY).$(MAJ)
 
 INSTALL = @INSTALL@
 INSTALL_PROGRAM = @INSTALL_PROGRAM@
@@ -75,7 +84,11 @@ YACC = @V_YACC@
 # problem if you don't own the file but can write to the directory.
 .c.o:
 	@rm -f $@
-	$(CC) $(CFLAGS) -c $(srcdir)/$*.c
+	$(CC) $(CFLAGS) -c -o $@ $(srcdir)/$*.c
+
+%_pic.o: %.c
+	@rm -f $@
+	$(CC) -fPIC $(CFLAGS) -c -o $@ $(srcdir)/$*.c
 
 PSRC =	pcap-@V_PCAP@.c @USB_SRC@ @BT_SRC@
 FSRC =  fad-@V_FINDALLDEVS@.c
@@ -90,6 +103,7 @@ SRC =	$(PSRC) $(FSRC) $(CSRC) $(SSRC) $(
 # We would like to say "OBJ = $(SRC:.c=.o)" but Ultrix's make cannot
 # hack the extra indirection
 OBJ =	$(PSRC:.c=.o) $(FSRC:.c=.o) $(CSRC:.c=.o) $(SSRC:.c=.o) $(GENSRC:.c=.o) $(LIBOBJS)
+OBJ_PIC = $(PSRC:.c=_pic.o) $(FSRC:.c=_pic.o) $(CSRC:.c=_pic.o) $(SSRC:.c=_pic.o) $(GENSRC:.c=_pic.o)
 HDR = \
 	acconfig.h \
 	arcnet.h \
@@ -122,7 +136,8 @@ TAGHDR = \
 TAGFILES = \
 	$(SRC) $(HDR) $(TAGHDR)
 
-CLEANFILES = $(OBJ) libpcap.a $(GENSRC) $(GENHDR) lex.yy.c
+CLEANFILES = $(OBJ) libpcap.a $(GENSRC) $(GENHDR) lex.yy.c \
+	$(OBJ_PIC) libpcap.so*
 
 MAN1 = pcap-config.1
 
@@ -311,7 +326,7 @@ EXTRA_DIST = \
 	Win32/Src/inet_net.c \
 	Win32/Src/inet_pton.c
 
-all: libpcap.a pcap-config
+all: libpcap.a pcap-config $(SHAREDLIB)
 
 libpcap.a: $(OBJ)
 	@rm -f $@
@@ -344,6 +359,13 @@ libpcap.dylib: $(OBJ)
 		-compatibility_version 1 \
 		-current_version `sed 's/[^0-9.].*$$//' $(srcdir)/VERSION`
 
+$(SHAREDLIB): $(OBJ_PIC)
+	-@rm -f $@
+	-@rm -f $(SOLIBRARY) $(SOLIBRARY).$(MAJ)
+	$(CC) $(CFLAGS_SHARED) -o $(SHAREDLIB) $(OBJ_PIC) -lc
+	ln -s $(SHAREDLIB) $(SOLIBRARY).$(MAJ)
+	ln -s $(SOLIBRARY).$(MAJ) $(SOLIBRARY)
+
 scanner.c: $(srcdir)/scanner.l
 	@rm -f $@
 	./runlex.sh $(LEX) -o$@ $<
@@ -351,6 +373,9 @@ scanner.c: $(srcdir)/scanner.l
 scanner.o: scanner.c tokdefs.h
 	$(CC) $(CFLAGS) -c scanner.c
 
+scanner_pic.o: scanner.c tokdefs.h
+	$(CC) -fPIC $(CFLAGS) -o $@ -c scanner.c
+
 pcap.o: version.h
 
 tokdefs.h: grammar.c
@@ -364,9 +389,17 @@ grammar.o: grammar.c
 	@rm -f $@
 	$(CC) $(CFLAGS) -Dyylval=pcap_lval -c grammar.c
 
+grammar_pic.o: grammar.c
+	@rm -f $@
+	$(CC) -fPIC $(CFLAGS) -Dyylval=pcap_lval -o $@ -c grammar.c
+
 version.o: version.c
 	$(CC) $(CFLAGS) -c version.c
 
+version_pic.o: version.c
+	$(CC) -fPIC $(CFLAGS) -c version.c -o $@
+
+
 snprintf.o: $(srcdir)/missing/snprintf.c
 	$(CC) $(CFLAGS) -o $@ -c $(srcdir)/missing/snprintf.c
 
@@ -392,6 +425,9 @@ bpf_filter.c: $(srcdir)/bpf/net/bpf_filt
 bpf_filter.o: bpf_filter.c
 	$(CC) $(CFLAGS) -c bpf_filter.c
 
+bpf_filter_pic.o: bpf_filter.c
+	$(CC) -fPIC $(CFLAGS) -c bpf_filter.c -o $@
+
 #
 # Generate the pcap-config script.
 #
@@ -418,6 +454,9 @@ install: libpcap.a pcap-config
 	    (mkdir -p $(DESTDIR)$(libdir); chmod 755 $(DESTDIR)$(libdir))
 	$(INSTALL_DATA) libpcap.a $(DESTDIR)$(libdir)/libpcap.a
 	$(RANLIB) $(DESTDIR)$(libdir)/libpcap.a
+	$(INSTALL_DATA) $(SHAREDLIB) $(DESTDIR)$(libdir)/
+	ln -sf $(SHAREDLIB) $(DESTDIR)$(libdir)/$(SOLIBRARY).$(MAJ)
+	ln -sf $(SOLIBRARY).$(MAJ) $(DESTDIR)$(libdir)/$(SOLIBRARY)
 	[ -d $(DESTDIR)$(includedir) ] || \
 	    (mkdir -p $(DESTDIR)$(includedir); chmod 755 $(DESTDIR)$(includedir))
 	[ -d $(DESTDIR)$(includedir)/pcap ] || \
--- a/configure
+++ b/configure
@@ -8658,7 +8658,7 @@ irix*)
 	;;
 
 linux*)
-	V_CCOPT="$V_CCOPT -fPIC"
+	V_CCOPT="$V_CCOPT"
 	;;
 
 osf*)
--- a/configure.in
+++ b/configure.in
@@ -943,7 +943,7 @@ irix*)
 	;;
 
 linux*)
-	V_CCOPT="$V_CCOPT -fPIC"
+	V_CCOPT="$V_CCOPT"
 	;;
 
 osf*)
