Add hello.c example

Makefile

@@ -32,13 +32,15 @@ endif
 # Link against thread lib
 LDFLAGS += -pthread
 
+export
+
 # Build for distribution
 .PHONY: distro
 distro: shared tools $(DOC_TARGETS)
 
 # Build everything...
 .PHONY: all
-all: shared static $(DOC_TARGETS) check
+all: shared static tools examples $(DOC_TARGETS) check
 
 # Shared libraries (versioned and unversioned)
 .PHONY: shared
@@ -53,6 +55,11 @@ static: $(LIB)/libredisx.a
 tools: shared
 	make -f tools.mk
 
+# Examples
+.PHONY: examples
+examples: shared
+	make -f examples.mk
+
 # Run regression tests
 .PHONY: test
 test:
@@ -147,7 +154,7 @@ INSTALL_PROGRAM ?= install
 INSTALL_DATA ?= install -m 644
 
 .PHONY: install
-install: install-libs install-bin install-man install-headers install-html
+install: install-libs install-bin install-man install-headers install-examples install-html
 
 .PHONY: install-libs
 install-libs:
@@ -175,13 +182,18 @@ install-man:
 	@install -d $(DESTDIR)$(mandir)/man1
 	$(INSTALL_DATA) -D man/man1/* $(DESTDIR)$(mandir)/man1
 
-
 .PHONY: install-headers
 install-headers:
 	@echo "installing headers to $(DESTDIR)$(includedir)"
 	install -d $(DESTDIR)$(includedir)
 	$(INSTALL_DATA) -D include/* $(DESTDIR)$(includedir)/
 
+.PHONY: install-examples
+install-examples:
+	@echo "installing examples to $(DESTDIR)$(docdir)"
+	install -d $(DESTDIR)$(docdir)
+	$(INSTALL_DATA) -D examples/* $(DESTDIR)$(docdir)/
+
 .PHONY: install-html
 install-html:
 ifneq ($(wildcard apidoc/html/search/*),)
@@ -211,6 +223,7 @@ help:
 	@echo "  analyze       Performs static analysis with 'cppcheck'."
 	@echo "  all           All of the above."
 	@echo "  distro        shared libs and documentation (default target)."
+	@echo "  examples      Build example programs."
 	@echo "  install       Install components (e.g. 'make prefix=<path> install')"
 	@echo "  clean         Removes intermediate products."
 	@echo "  distclean     Deletes all generated files."

examples.mk

@@ -0,0 +1,11 @@
+SRC := examples
+
+include config.mk
+
+LDFLAGS += -L$(LIB) -lredisx
+LD_LIBRARY_PATH := $(LIB):$(LD_LIBRARY_PATH)
+
+.PHONY: all
+all: $(BIN)/hello
+
+include build.mk

examples/hello.c

@@ -0,0 +1,60 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <redisx.h>
+
+
+/*
+ * Pings a Redis server with a hello message, and prints the response, or else an error.
+ *
+ * Usage: hello [host]
+ *
+ * Options:
+ *    host      The Redis server host (default: "127.0.0.1")
+ *
+ * Exit status:
+ *    0         Successful completion
+ *    1         Could not connect to Redis server
+ *    2         Bad response from server
+ *
+ * Author: Attila Kovacs
+ * Version: 19 December 2024
+ */
+int main(int argc, char *argv[]) {
+  // Initialize for Redis server at 'my-server.com'.
+  Redis *redis;
+  char *host = "127.0.0.1";     // Default host
+
+  if(argc > 1) host = argv[1];  // program argument designates host
+
+  // Initialize with the designated or default host
+  redis = redisxInit(host);
+
+  // Connect to Redis / Valkey server
+  if(redis != NULL && redisxConnect(redis, FALSE) == X_SUCCESS) {
+
+    // Run 'GET my-key' query on the server 
+    RESP *reply = redisxRequest(redis, "PING", "Hello World!", NULL, NULL, NULL);
+
+    // Check that we got a response of the expected type (bulk string of any length)
+    if(redisxCheckRESP(reply, RESP_BULK_STRING, 0) == X_SUCCESS)
+      printf("%s\n", (char *) reply->value);
+    else {
+      fprintf(stderr, "ERROR! bad response\n"); 
+      return 2;
+    }
+
+    // Clean up
+    redisxDestroyRESP(reply);
+    redisxDisconnect(redis);
+  }
+  else {
+    perror("ERROR! could not connect");
+    return 1;
+  }
+
+  // Free up the resources used by the 'redis' instance.
+  redisxDestroy(redis);
+
+  return 0;
+}