Hacky, blocking terminal I/O.

Author: rmacnak

vm/primitives.cc

@@ -20,7 +20,13 @@
 #if defined(OS_MACOS)
 #include <crt_externs.h>
 #else
-extern char** environ;
+extern "C" char** environ;
+#endif
+
+#if defined(OS_MACOS) || defined(OS_LINUX)
+#include <sys/ioctl.h>
+#include <termios.h>
+#include <unistd.h>
 #endif
 
 #include "vm/assert.h"
@@ -274,6 +280,11 @@ const bool kFailure = false;
   V(355, Pipe_write)                                                           \
   V(356, Pipe_close)                                                           \
   V(357, Process_environment)                                                  \
+  V(500, Term_start)                                                           \
+  V(501, Term_stop)                                                            \
+  V(502, Term_read)                                                            \
+  V(503, Term_write)                                                           \
+  V(504, Term_size)                                                            \
   V(509, print)                                                                \
   V(510, readFileAsBytes)                                                      \
   V(511, writeBytesToFile)
@@ -4007,6 +4018,95 @@ DEFINE_PRIMITIVE(Object_yourself) {
   return kSuccess;
 }
 
+#if defined(OS_MACOS) || defined(OS_LINUX)
+static struct termios original_term;
+#endif
+
+DEFINE_PRIMITIVE(Term_start) {
+  ASSERT(num_args == 0);
+#if defined(OS_MACOS) || defined(OS_LINUX)
+  intptr_t status = tcgetattr(STDIN_FILENO, &original_term);
+  if (status == 0) {
+    struct termios term;
+    status = tcgetattr(STDIN_FILENO, &term);
+    if (status == 0) {
+      term.c_iflag &= ~(IXON|IXOFF|ICRNL);
+      term.c_oflag &= ~(OPOST);
+      term.c_lflag &= ~(ECHO|ECHONL|ICANON|ISIG|IEXTEN);
+      status = tcsetattr(STDIN_FILENO, TCSANOW, &term);
+    }
+  }
+  RETURN_SMI(status);
+#else
+  return kFailure;
+#endif
+}
+
+DEFINE_PRIMITIVE(Term_stop) {
+  ASSERT(num_args == 0);
+#if defined(OS_MACOS) || defined(OS_LINUX)
+  intptr_t status = tcsetattr(STDIN_FILENO, TCSANOW, &original_term);
+  RETURN_SMI(status);
+#else
+  return kFailure;
+#endif
+}
+
+DEFINE_PRIMITIVE(Term_size) {
+  ASSERT(num_args == 0);
+#if defined(OS_MACOS) || defined(OS_LINUX)
+  struct winsize w;
+  w.ws_col = 0;
+  w.ws_row = 0;
+  intptr_t status = ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
+  if (status != 0) {
+    RETURN_SMI(status);
+  }
+  Array result = H->AllocateArray(2);
+  result.set_element(0, SmallInteger::New(w.ws_row));
+  result.set_element(1, SmallInteger::New(w.ws_col));
+  RETURN(result);
+#else
+  return kFailure;
+#endif
+}
+
+DEFINE_PRIMITIVE(Term_write) {
+  ASSERT(num_args == 1);
+#if defined(OS_MACOS) || defined(OS_LINUX)
+  Bytes buffer = static_cast<Bytes>(I->Stack(0));
+  if (!buffer->IsBytes()) return kFailure;
+
+  size_t length = buffer->Size();
+  size_t start = 0;
+  while (start != length) {
+    size_t written = write(STDOUT_FILENO,
+                           buffer->element_addr(start),
+                           length - start);
+    if (written == 0) {
+      FATAL("Failed to write");
+    }
+    start += written;
+  }
+  RETURN_SELF();
+#else
+  return kFailure;
+#endif
+}
+
+DEFINE_PRIMITIVE(Term_read) {
+  ASSERT(num_args == 0);
+#if defined(OS_MACOS) || defined(OS_LINUX)
+  uint8_t byte;
+  if (read(STDIN_FILENO, &byte, 1) <= 0) {
+    FATAL("Failed to read");
+  }
+  RETURN_SMI(static_cast<intptr_t>(byte));
+#else
+  return kFailure;
+#endif
+}
+
 PrimitiveFunction* Primitives::primitive_table_[kNumPrimitives] = {};
 
 void Primitives::Startup() {