Added configuration test for hstrerror().

dns/GNUmakefile

@@ -10,4 +10,11 @@ clean:
 distclean: clean
 	rm -f *.d
 
+cfg/%:
+	$(MAKE) -C cfg all
+
+gethostbyname: gethostbyname.o hstrerror.o
+
+hstrerror.o: cfg/have_hstrerror.h
+
 -include *.d

dns/cfg/GNUmakefile

@@ -0,0 +1,4 @@
+all: have_hstrerror.h
+
+%.h: %.sh
+	CC='$(CC)' CFLAGS='$(CFLAGS)' LDFLAGS='$(LDFLAGS)' sh $^ > $@

dns/cfg/have_hstrerror.sh

@@ -0,0 +1,11 @@
+cat > has_hstrerror_$$.c <<EOF
+#include <netdb.h>
+int main(void) { hstrerror(0); }
+EOF
+if $CC $CFLAGS has_hstrerror_$$.c $LDFLAGS -o has_hstrerror_$$
+then
+	echo '#define HAVE_HSTRERROR 1'
+else 
+	echo '#define HAVE_HSTRERROR 0'
+fi
+rm has_hstrerror_$$.c has_hstrerror_$$

dns/gethostbyname.c

@@ -1,5 +1,8 @@
 #include <netdb.h>
 #include <stdio.h>
+#include <stdlib.h>
+
+#include "hstrerror.h"
 
 char *cmnd;
 
@@ -36,7 +39,7 @@ int main(int argc, char **argv) {
 	}
 	for (a = he->h_addr_list; *a; a++) {
 	    int j;
-	    printf("\tAddress:   ");
+	    printf("\tAddress:    ");
 	    for (j = 0; j < he->h_length; j++) {
 		printf("%s%d", j ? "." : "", (unsigned char)(*a)[j]);
 	    }

dns/hstrerror.c

@@ -0,0 +1,11 @@
+#include "cfg/have_hstrerror.h"
+#include "hstrerror.h"
+
+#if (!HAVE_HSTRERROR)
+const char *hstrerror(int err) {
+    static char errstr[80];
+
+    snprintf(errstr, sizeof(errstr), "resolver error %d", err);
+    return errstr;
+}
+#endif

dns/hstrerror.h

@@ -0,0 +1 @@
+const char * hstrerror(int err);