commit 4dda199dbd9efecf81fee7648a213c7d7751be0d
Author: David Sorber <david.sorber@gmail.com>
Date:   Fri Mar 4 09:53:46 2016 -0500

    Adding a very simple unix domain socket example client and server.

diff --git a/software/misc/unix_socket/Makefile b/software/misc/unix_socket/Makefile
new file mode 100644
index 0000000..c3cafac
--- /dev/null
+++ b/software/misc/unix_socket/Makefile
@@ -0,0 +1,21 @@
+CC	 = gcc
+
+HEADERS = $(wildcard *.h)
+SOURCES = $(wildcard *.c)
+OBJECTS = $(patsubst %.c,%.o,$(SOURCES))
+
+CFLAGS 	+= -O2 -Wall -std=c99
+CWD 	:= $(shell pwd)
+
+all: server client
+
+server: server.c
+	$(CC) $(CFLAGS) server.c -o server
+
+client: client.c
+	$(CC) $(CFLAGS) client.c -o client
+
+clean:
+	@rm -f *.o 
+	@rm -f server
+	@rm -f client
diff --git a/software/misc/unix_socket/client.c b/software/misc/unix_socket/client.c
new file mode 100644
index 0000000..984fe2d
--- /dev/null
+++ b/software/misc/unix_socket/client.c
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include <string.h>
+
+#define UNIX_PATH_MAX    108
+
+int main(void)
+{
+    struct sockaddr_un address;
+    int  socket_fd, nbytes;
+    char buffer[256];
+
+    socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (socket_fd < 0)
+    {
+        printf("socket() failed\n");
+        return 1;
+    }
+
+    /* start with a clean address structure */
+    memset(&address, 0, sizeof(struct sockaddr_un));
+ 
+    address.sun_family = AF_UNIX;
+    snprintf(address.sun_path, UNIX_PATH_MAX, "./demo_socket");
+
+    if (connect(socket_fd, (struct sockaddr *)&address,  
+                sizeof(struct sockaddr_un)) != 0)
+    {
+        printf("connect() failed\n");
+        return 1;
+    }
+
+    nbytes = snprintf(buffer, 256, "hello from a client");
+    write(socket_fd, buffer, nbytes);
+ 
+    nbytes = read(socket_fd, buffer, 256);
+    buffer[nbytes] = 0;
+
+    printf("MESSAGE FROM SERVER: %s\n", buffer);
+
+    close(socket_fd);
+
+    return 0;
+}
diff --git a/software/misc/unix_socket/server.c b/software/misc/unix_socket/server.c
new file mode 100644
index 0000000..6e57e80
--- /dev/null
+++ b/software/misc/unix_socket/server.c
@@ -0,0 +1,80 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/types.h>
+
+#define UNIX_PATH_MAX    108
+
+
+int connection_handler(int connection_fd)
+{
+    int nbytes;
+    char buffer[256];
+
+    nbytes = read(connection_fd, buffer, 256);
+    buffer[nbytes] = 0;
+
+    printf("MESSAGE FROM CLIENT: %s\n", buffer);
+    nbytes = snprintf(buffer, 256, "hello from the server");
+    write(connection_fd, buffer, nbytes);
+ 
+    close(connection_fd);
+    return 0;
+}
+
+int main(void)
+{
+    struct sockaddr_un address;
+    int socket_fd, connection_fd;
+    socklen_t address_length;
+    pid_t child;
+ 
+    socket_fd = socket(PF_UNIX, SOCK_STREAM, 0);
+    if (socket_fd < 0)
+    {
+        printf("socket() failed\n");
+        return 1;
+    } 
+
+    unlink("./demo_socket");
+
+    /* start with a clean address structure */
+    memset(&address, 0, sizeof(struct sockaddr_un));
+
+    address.sun_family = AF_UNIX;
+    snprintf(address.sun_path, UNIX_PATH_MAX, "./demo_socket");
+
+    if (bind(socket_fd, (struct sockaddr *)&address, 
+             sizeof(struct sockaddr_un)) != 0)
+    {
+        printf("bind() failed\n");
+        return 1;
+    }
+
+    if (listen(socket_fd, 5) != 0)
+    {
+        printf("listen() failed\n");
+        return 1;
+    }
+
+    while ((connection_fd = accept(socket_fd, (struct sockaddr *)&address,
+                                   &address_length)) > -1)
+    {
+        child = fork();
+        if (child == 0)
+        {
+            /* now inside newly created connection handling process */
+            return connection_handler(connection_fd);
+        }
+
+        /* still inside server process */
+        close(connection_fd);
+    }
+
+    close(socket_fd);
+    unlink("./demo_socket");
+    return 0;
+}