diff --git a/samples/tmo_shell/src/tmo_shell.c b/samples/tmo_shell/src/tmo_shell.c
index 58b7a8b..ec5ada9 100644
--- a/samples/tmo_shell/src/tmo_shell.c
+++ b/samples/tmo_shell/src/tmo_shell.c
@@ -556,7 +556,13 @@ int sock_connect(const struct shell *shell, size_t argc, char **argv)
 	int ret;
 	char *host;
 	struct sockaddr target;
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	char *port_st = argv[3];
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
@@ -680,7 +686,13 @@ int sock_bind(const struct shell *shell, size_t argc, char **argv)
 		shell_help(shell);
 		return -EINVAL;
 	}
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -713,7 +725,13 @@ int sock_send(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -745,7 +763,13 @@ int sock_sendto(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -834,7 +858,13 @@ int sock_sendb(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -929,7 +959,13 @@ int sock_recvb(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -984,6 +1020,11 @@ int sock_rcv(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 	int sd = (int)strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -1029,6 +1070,11 @@ int sock_rcvfrom(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 	int sd = (int)strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -1083,7 +1129,13 @@ int sock_close(const struct shell *shell, size_t argc, char **argv)
 		shell_help(shell);
 		return -EINVAL;
 	}
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -1120,7 +1172,13 @@ int sock_sendsms(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {
@@ -1152,9 +1210,19 @@ int sock_recvsms(const struct shell *shell, size_t argc, char **argv)
 		return -EINVAL;
 	}
 
+	errno = 0;
 	int sd = strtol(argv[1], NULL, 10);
-
+	if (errno != 0) {
+		shell_error(shell, "Socket %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int wait = strtol(argv[2], NULL, 10);
+	if (errno != 0 && errno != ERANGE) {
+		shell_error(shell, "Timeout %s is invalid, errno = %d; %s", argv[1], errno,
+			    strerror(errno));
+		return errno;
+	}
 	int sock_idx;
 	for (sock_idx = 0; sock_idx < MAX_SOCK_REC; sock_idx++) {
 		if (socks[sock_idx].sd == sd && socks[sock_idx].flags & BIT(sock_open)) {