diff --git a/src/env.c b/src/env.c
new file mode 100644
index 0000000..cca6670
--- /dev/null
+++ b/src/env.c
@@ -0,0 +1,33 @@
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(const int argc, char **argv, const char **envp) {
+	int i;
+	for (i = 1; i < argc; i++) {
+		char *val = strchr(argv[i], '=');
+		if (!val)
+			break;
+
+		val[0] = '\0';
+
+		if (setenv(argv[i], val + 1, 1)) {
+			fprintf(stderr, "env: %s\n", strerror(errno));
+			return 1;
+		}
+	}
+
+	/* Print env */
+	if (i == argc) {
+		while (*envp)
+			puts(*envp++);
+
+		return 0;
+	}
+
+	execvp(argv[i], argv + i);
+	fprintf(stderr, "env: %s\n", strerror(errno));
+	return 1;
+}
diff --git a/src/tty.c b/src/tty.c
new file mode 100644
index 0000000..5b9a558
--- /dev/null
+++ b/src/tty.c
@@ -0,0 +1,13 @@
+#include <unistd.h>
+#include <stdio.h>
+
+int main(void) {
+	char *tty = ttyname(STDIN_FILENO);
+	if (tty)
+		puts(tty);
+
+	else
+		puts("not a tty");
+
+	return tty == NULL;
+}
diff --git a/src/whoami.c b/src/whoami.c
new file mode 100644
index 0000000..ddff8a9
--- /dev/null
+++ b/src/whoami.c
@@ -0,0 +1,18 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void) {
+	struct passwd *pw = getpwuid(getuid());
+	if (!pw) {
+		fprintf(stderr, "whoami: %s\n", strerror(errno));
+		return 1;
+	}
+
+	puts(pw->pw_name);
+	return 0;
+}