Workaround for the absence of 'zlib' on Microsoft Windows. (Ideally, the workaround would be to actually have the relevant library. I'll deal with that if/when a Windows version becomes an issue.)

Author: Bill-Gray

makefile

@@ -32,17 +32,6 @@ endif
 EXE=
 RM=rm -f
 
-# I'm using 'mkdir -p' to avoid error messages if the directory exists.
-# It may fail on very old systems,  and will probably fail on non-POSIX
-# systems.  If so,  change to '-mkdir' and ignore errors.
-
-ifdef MSWIN
-	EXE=.exe
-	MKDIR=-mkdir
-else
-	MKDIR=mkdir -p
-endif
-
 LIB_DIR=$(INSTALL_DIR)/lib
 
 ifdef W64
@@ -59,6 +48,17 @@ ifdef W32
 	LIB_DIR=$(INSTALL_DIR)/win_lib32
 endif
 
+# I'm using 'mkdir -p' to avoid error messages if the directory exists.
+# It may fail on very old systems,  and will probably fail on non-POSIX
+# systems.  If so,  change to '-mkdir' and ignore errors.
+
+ifeq ($(EXE),.exe)
+	MKDIR=-mkdir
+else
+	ZLIB=-lz
+	MKDIR=mkdir -p
+endif
+
 # You can have your include files in ~/include and libraries in
 # ~/lib,  in which case only the current user can use them;  or
 # (with root privileges) you can install them to /usr/local/include
@@ -179,19 +179,19 @@ libsatell.a: $(OBJS)
 	ar rv libsatell.a $(OBJS)
 
 sat_eph$(EXE):	 	sat_eph.c	observe.o libsatell.a
-	$(CC) $(CFLAGS) -o sat_eph$(EXE) -I $(INCL) sat_eph.c observe.o libsatell.a -lm -L $(LIB_DIR) -llunar -lz
+	$(CC) $(CFLAGS) -o sat_eph$(EXE) -I $(INCL) sat_eph.c observe.o libsatell.a -lm -L $(LIB_DIR) -llunar $(ZLIB)
 
 sat_cgi$(EXE):	 	sat_eph.c	observe.o libsatell.a
-	$(CC) $(CFLAGS) -o sat_cgi$(EXE) -I $(INCL) sat_eph.c observe.o -DON_LINE_VERSION libsatell.a -lm -L $(LIB_DIR) -llunar -lz
+	$(CC) $(CFLAGS) -o sat_cgi$(EXE) -I $(INCL) sat_eph.c observe.o -DON_LINE_VERSION libsatell.a -lm -L $(LIB_DIR) -llunar $(ZLIB)
 
 sat_id$(EXE):	 	sat_id.cpp sat_util.o	observe.o libsatell.a
-	$(CXX) $(CFLAGS) -o sat_id$(EXE) -I $(INCL) sat_id.cpp sat_util.o observe.o libsatell.a -lm -L $(LIB_DIR) -llunar -lz
+	$(CXX) $(CFLAGS) -o sat_id$(EXE) -I $(INCL) sat_id.cpp sat_util.o observe.o libsatell.a -lm -L $(LIB_DIR) -llunar $(ZLIB)
 
 sat_id2$(EXE):	 	sat_id2.cpp sat_id.cpp sat_util.o observe.o libsatell.a
-	$(CXX) $(CFLAGS) -o sat_id2$(EXE) -I $(INCL) -DON_LINE_VERSION sat_id2.cpp sat_id.cpp sat_util.o observe.o libsatell.a -lm -L $(LIB_DIR) -llunar -lz
+	$(CXX) $(CFLAGS) -o sat_id2$(EXE) -I $(INCL) -DON_LINE_VERSION sat_id2.cpp sat_id.cpp sat_util.o observe.o libsatell.a -lm -L $(LIB_DIR) -llunar $(ZLIB)
 
 sat_id3$(EXE):	 	sat_id3.cpp sat_id.cpp sat_util.o observe.o libsatell.a
-	$(CXX) $(CFLAGS) -o sat_id3$(EXE) -I $(INCL) -DON_LINE_VERSION sat_id3.cpp sat_id.cpp sat_util.o observe.o libsatell.a -lm -L $(LIB_DIR) -llunar -lz
+	$(CXX) $(CFLAGS) -o sat_id3$(EXE) -I $(INCL) -DON_LINE_VERSION sat_id3.cpp sat_id.cpp sat_util.o observe.o libsatell.a -lm -L $(LIB_DIR) -llunar $(ZLIB)
 
 summarize$(EXE):	 	summarize.c	observe.o libsatell.a
 	$(CC) $(CFLAGS) -o summarize$(EXE) -I $(INCL) summarize.c observe.o libsatell.a -lm -L $(LIB_DIR) -llunar

sat_eph.c

@@ -6,7 +6,11 @@
 #include <assert.h>
 #include <math.h>
 #include <time.h>
-#include <zlib.h>
+#if defined( _WIN32) || defined( __WATCOMC__)
+   #include "zlibstub.h"
+#else
+   #include <zlib.h>
+#endif
 #include "watdefs.h"
 #include "afuncs.h"
 #include "comets.h"

sat_id.cpp

@@ -65,11 +65,12 @@ should be used,  and the others are suppressed.       */
 #include <ctype.h>
 #include <stdlib.h>
 #include <assert.h>
-#include <zlib.h>
 #if defined( _WIN32) || defined( __WATCOMC__)
    #include <malloc.h>     /* for alloca() prototype */
+   #include "zlibstub.h"
 #else
    #include <unistd.h>
+   #include <zlib.h>
 #endif
 
 #if defined(_MSC_VER) && _MSC_VER < 1900

zlibstub.h

@@ -0,0 +1,4 @@
+#define gzFile FILE *
+#define gzopen fopen
+#define gzgets( ifile, buff, buffsize)    fgets( buff, buffsize, ifile)
+#define gzclose fclose