--- Makefile	2022-07-03 19:49:29.000000000 +0200
+++ Makefile	2022-07-26 11:44:36.474008372 +0200
@@ -75,6 +75,7 @@
 
 # What's this release's version? Part of the directory and archive file name.
 VERSION = 1.0-pl20
+DOTTED_VERSION = 1.0.20
 
 # Where do you want to install the gsm library, header file, and manpages?
 #
@@ -99,7 +100,7 @@
 #  Other tools
 
 SHELL		= /bin/sh
-LN		= ln
+LN		= ln -s -f
 BASENAME 	= basename
 AR		= ar
 ARFLAGS		= cr
@@ -142,7 +143,7 @@
 
 # Targets
 
-LIBGSM	= $(LIB)/libgsm.a
+LIBGSMSO	= $(LIB)/libgsm.so
 
 TOAST	= $(BIN)/toast
 UNTOAST	= $(BIN)/untoast
@@ -260,7 +261,7 @@
 # Install targets
 
 GSM_INSTALL_TARGETS =	\
-		$(GSM_INSTALL_LIB)/libgsm.a		\
+		$(GSM_INSTALL_LIB)/libgsm.so		\
 		$(GSM_INSTALL_INC)/gsm.h		\
 		$(GSM_INSTALL_MAN)/gsm.3		\
 		$(GSM_INSTALL_MAN)/gsm_explode.3	\
@@ -282,7 +283,7 @@
 
 # Target rules
 
-all:		$(LIBGSM) $(TOAST) $(TCAT) $(UNTOAST)
+all:		$(LIBGSMSO) $(TOAST) $(TCAT) $(UNTOAST)
 		@-echo $(ROOT): Done.
 
 tst:		$(TST)/lin2cod $(TST)/cod2lin $(TOAST) $(TST)/test-result
@@ -302,16 +303,16 @@
 
 # The basic API: libgsm
 
-$(LIBGSM):	$(LIB) $(GSM_OBJECTS)
-		-rm $(RMFLAGS) $(LIBGSM)
-		$(AR) $(ARFLAGS) $(LIBGSM) $(GSM_OBJECTS)
-		$(RANLIB) $(LIBGSM)
+$(LIBGSMSO):	$(LIB) $(GSM_OBJECTS)
+		$(LD) -shared -Wl,-soname,libgsm.so.1 -o $@.$(DOTTED_VERSION) $(GSM_OBJECTS)
+		$(LN) `$(BASENAME) $@.$(DOTTED_VERSION)` $@.1
+		$(LN) `$(BASENAME) $@.$(DOTTED_VERSION)` $@
 
 
 # Toast, Untoast and Tcat -- the compress-like frontends to gsm.
 
-$(TOAST):	$(BIN) $(TOAST_OBJECTS) $(LIBGSM)
-		$(LD) $(LFLAGS) -o $(TOAST) $(TOAST_OBJECTS) $(LIBGSM) $(LDLIB)
+$(TOAST):	$(BIN) $(TOAST_OBJECTS) $(LIBGSMSO)
+		$(LD) $(LFLAGS) -o $(TOAST) $(TOAST_OBJECTS) $(LIBGSMSO) $(LDLIB)
 
 $(UNTOAST):	$(BIN) $(TOAST)
 		-rm $(RMFLAGS) $(UNTOAST)
@@ -396,10 +397,12 @@
 		cp $? $@
 		chmod 444 $@
 
-$(GSM_INSTALL_LIB)/libgsm.a:	$(LIBGSM)
-		-rm $(RMFLAGS) $@
-		cp $? $@
-		chmod 444 $@
+$(GSM_INSTALL_LIB)/libgsm.so:	$(LIBGSMSO)
+		-rm $(RMFLAGS) $@ $@.1 $@.$(DOTTED_VERSION)
+		cp $?.$(DOTTED_VERSION) $@.$(DOTTED_VERSION)
+		chmod 755 $@.$(DOTTED_VERSION)
+		$(LN) libgsm.so.$(DOTTED_VERSION) $@
+		$(LN) libgsm.so.$(DOTTED_VERSION) $@.1
 
 
 # Distribution
@@ -428,7 +431,7 @@
 			-print | xargs rm $(RMFLAGS)
 
 clean:	semi-clean
-		-rm $(RMFLAGS) $(LIBGSM) $(ADDTST)/add		\
+		-rm $(RMFLAGS) $(LIBGSMSO)* $(ADDTST)/add		\
 			$(TOAST) $(TCAT) $(UNTOAST)	\
 			$(ROOT)/gsm-1.0.tar.gz
 
@@ -476,22 +479,22 @@
 $(TST)/test-result:	$(TST)/lin2cod $(TST)/cod2lin $(TOAST) $(TST)/run
 			( cd $(TST); ./run ) 
 
-$(TST)/lin2txt:		$(TST)/lin2txt.o $(LIBGSM)
+$(TST)/lin2txt:		$(TST)/lin2txt.o $(LIBGSMSO)
 			$(LD) $(LFLAGS) -o $(TST)/lin2txt \
-				$(TST)/lin2txt.o $(LIBGSM) $(LDLIB)
+				$(TST)/lin2txt.o $(LIBGSMSO) $(LDLIB)
 
-$(TST)/lin2cod:		$(TST)/lin2cod.o $(LIBGSM)
+$(TST)/lin2cod:		$(TST)/lin2cod.o $(LIBGSMSO)
 			$(LD) $(LFLAGS) -o $(TST)/lin2cod \
-				$(TST)/lin2cod.o $(LIBGSM) $(LDLIB)
+				$(TST)/lin2cod.o $(LIBGSMSO) $(LDLIB)
 
-$(TST)/gsm2cod:		$(TST)/gsm2cod.o $(LIBGSM)
+$(TST)/gsm2cod:		$(TST)/gsm2cod.o $(LIBGSMSO)
 			$(LD) $(LFLAGS) -o $(TST)/gsm2cod \
-				$(TST)/gsm2cod.o $(LIBGSM) $(LDLIB)
+				$(TST)/gsm2cod.o $(LIBGSMSO) $(LDLIB)
 
-$(TST)/cod2txt:		$(TST)/cod2txt.o $(LIBGSM)
+$(TST)/cod2txt:		$(TST)/cod2txt.o $(LIBGSMSO)
 			$(LD) $(LFLAGS) -o $(TST)/cod2txt \
-				$(TST)/cod2txt.o $(LIBGSM) $(LDLIB)
+				$(TST)/cod2txt.o $(LIBGSMSO) $(LDLIB)
 
-$(TST)/cod2lin:		$(TST)/cod2lin.o $(LIBGSM)
+$(TST)/cod2lin:		$(TST)/cod2lin.o $(LIBGSMSO)
 			$(LD) $(LFLAGS) -o $(TST)/cod2lin \
-				$(TST)/cod2lin.o $(LIBGSM) $(LDLIB)
+				$(TST)/cod2lin.o $(LIBGSMSO) $(LDLIB)