sockets: add a tcp server example

2 files changed, 91 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 59b02eb..686a8d7 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,6 @@
 BINS = ascii class depipe_strings dup fpipe pipe realloc strpbrk strsep \
-       tokenizer getopt prime_mask linked_list pi_bbp string_tokenizer
+       tokenizer getopt prime_mask linked_list pi_bbp string_tokenizer  \
+       tcpserver
 CC = gcc
 CFLAGS = -Wall -std=gnu99 -pedantic
 DBGFLAGS = -g -O0
diff --git a/tcpserver.c b/tcpserver.c
new file mode 100644
index 0000000..5eca180
--- /dev/null
+++ b/tcpserver.c
@@ -0,0 +1,89 @@
+/* tcpserver.c
+ *
+ * TCP Server
+ * note: 'echo "hello" | nc localhost 8080' to send messages to the server
+ *
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+int main(int argc, char **argv)
+{
+    if (argc != 3)
+    {
+        fprintf(stderr, "usage: %s <port> <dir>\n", argv[0]);
+        exit(1);
+    }
+
+    int server_sockfd, ret;
+
+    if ((server_sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
+    {
+        perror("socket");
+        close(server_sockfd);
+        exit(-1);
+    }
+
+    /* allow fast reuse of ports */
+    int reuse_true = 1;
+    setsockopt(server_sockfd, SOL_SOCKET, SO_REUSEADDR, &reuse_true,
+               sizeof(reuse_true));
+
+    struct sockaddr_in addr;
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(atoi(argv[1]));
+    addr.sin_addr.s_addr = INADDR_ANY;
+
+    if (bind(server_sockfd, (struct sockaddr *) &addr, sizeof(addr)) == -1)
+    {
+        perror("bind");
+        exit(-1);
+    }
+
+    struct sockaddr_in remote_addr;
+    unsigned int socklen = sizeof(remote_addr);
+
+    while (1)
+    {
+        if (listen(server_sockfd, 0) == -1)
+        {
+            perror("listen");
+            exit(-1);
+        }
+
+        int sockfd;
+        sockfd = accept(server_sockfd, (struct sockaddr *) &remote_addr, &socklen);
+        if (sockfd == -1)
+        {
+            perror("socket");
+            close(sockfd);
+            exit(-1);
+        }
+
+        char buf[255] = { 0 };
+        if ((ret = recv(sockfd, buf, sizeof(buf), 0)) < 0)
+        {
+            perror("recv");
+            exit(-1);
+        }
+
+        printf("%s", buf);
+        shutdown(sockfd, SHUT_RDWR);
+        close(sockfd);
+    }
+
+    shutdown(server_sockfd, SHUT_RDWR);
+    close(server_sockfd);
+}
+