1 files changed, 11 insertions, 0 deletions
diff --git a/userland/libc/unistd/isatty.c b/userland/libc/unistd/isatty.c
new file mode 100644
index 0000000..d8b08c3
--- /dev/null
+++ b/userland/libc/unistd/isatty.c
@@ -0,0 +1,11 @@
+#include <syscall.h>
+#include <unistd.h>
+#include <errno.h>
+
+int isatty(int fd) {
+  int rc = syscall(SYS_ISATTY, fd, 0, 0, 0, 0);
+  if (1 == rc)
+    return rc;
+  errno = -rc;
+  return 0;
+}