exemple minimal compilable

code/network/.gitignore

@@ -0,0 +1 @@
+emc-tnetd

code/network/Makefile

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+#
+#	NETWORK EXPERIMENTS
+#
+
+COPT = -Wall -DDEBUG_LEVEL=1 -pthread
+
+# --------------------------------------------------
+#	Experimental Specialized Telnet Server
+#	(Exemple Minimal Compilable)
+
+emc-tnetd:		emc-tnetd.c Makefile
+	gcc $< $(COPT) -o $@

code/network/README.md

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+= Network / Réseau
+
+Some experiments on network programming.
+
+== Telnet server
+
+Une étude pour pouvoir intégrer un accès "console" à n'importe quelle
+application. La première ébauche a rapidement permis de comprendre
+que c'est pas si simple que ça.
+
+Le fichier `emc-tnetd.c` a mis en évidence deux soucis.
+Sauras-tu les trouver ?
+
+
+

code/network/emc-tnetd.c

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+#include  <stdio.h>
+#include  <unistd.h>
+#include  <stdlib.h>
+#include <string.h>
+#include  <sys/socket.h>
+#include  <netinet/in.h>
+#include  <arpa/inet.h>
+
+#define TL 20
+
+int main(int argc, char *argv[])
+{
+int			foo, len, sock;
+char			*adr_ip = "127.0.0.1";
+int			port = 5678;
+unsigned int		addrlen;
+int			connected;
+struct sockaddr_in	addr;
+struct in_addr		ia;
+FILE			*fpin;
+char			line[TL+5], *ptr;
+
+fprintf(stderr, "--- %s ---\n", argv[0]);
+
+sock = socket(AF_INET, SOCK_STREAM, 0);
+if (sock < 0) {
+	perror(__FILE__ " start socket");
+	return -1;
+	}
+
+#define S sizeof(struct sockaddr_in)
+memset(&addr, 0, S); 
+addr.sin_family = AF_INET;
+addr.sin_port = htons(port);
+if (adr_ip && inet_aton(adr_ip, &ia)) {
+	addr.sin_addr = ia;
+	fprintf(stderr, "attached to %s\n", adr_ip);
+	}
+if ((foo=bind(sock, (struct sockaddr *)&addr, S)) < 0) {
+	perror(__FILE__ " fail on bind ");
+	close(sock);
+	return -2;
+	}
+fprintf(stderr, "bind -> %d\n", foo);
+
+foo = listen(sock, 5);		/* 5 is a bsd magic number */
+if (foo) {
+	perror(__FILE__ " no magic in listen ");
+	return -3;
+	}
+
+/* start of the endless loop */
+for (;;) {
+	fprintf(stderr, "accepting...\n");
+	addrlen = sizeof(struct sockaddr);
+	connected = accept(sock, (struct sockaddr *)&addr, &addrlen);
+	if (connected < 0) {
+		perror(__FILE__ " accept");
+		return -1;
+		}
+	fprintf(stderr, "accept -> %d\n", connected);
+
+	if (NULL==(fpin = fdopen(connected, "r+"))) {
+		perror(__FILE__ " fdopen on connected");
+		return -3;
+		}
+	// fprintf(stderr, "fopened...\n");
+
+	while ( (ptr=fgets(line, TL, fpin)) ) {
+		len = strlen(line);
+		fprintf(stderr, "   %3d  |  %s", len, line);
+		for (foo=0; foo<len; foo++) {
+			fprintf(fpin, "%02X ", (unsigned char)line[foo]);
+			}
+		fputs("\n", fpin);
+		}
+	close(connected);
+	} /* end of the endless loop */
+
+return 0;
+}