notcurses_term_dimensions() + unit test

include/notcurses.h

@@ -7,8 +7,12 @@ extern "C" {
 
 const char* notcurses_version(void);
 
-int notcurses_init(void);
-int notcurses_stop(void);
+struct notcurses;
+
+struct notcurses* notcurses_init(void);
+int notcurses_stop(struct notcurses* nc);
+
+int notcurses_term_dimensions(struct notcurses* n, int* rows, int* cols);
 
 #ifdef __cplusplus
 } // extern "C"

src/bin/demo.c

@@ -1,11 +1,19 @@
+#include <stdio.h>
 #include <stdlib.h>
 #include <notcurses.h>
 
 int main(void){
-  if(notcurses_init()){
+  struct notcurses* nc;
+  int x, y;
+  if((nc = notcurses_init()) == NULL){
     return EXIT_FAILURE;
   }
-  if(notcurses_stop()){
+  if(notcurses_term_dimensions(nc, &y, &x)){
+    notcurses_stop(nc);
+    return EXIT_FAILURE;
+  }
+  printf("Dimensions: %d rows x %d cols\n", y, x);
+  if(notcurses_stop(nc)){
     return EXIT_FAILURE;
   }
   return EXIT_SUCCESS;

src/lib/notcurses.c

@@ -1,6 +1,16 @@
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
 #include "notcurses.h"
 #include "version.h"
 
+typedef struct notcurses {
+  int ttyfd;  // file descriptor for controlling tty
+} notcurses;
+
 static const char NOTCURSES_VERSION[] =
  notcurses_VERSION_MAJOR "."
  notcurses_VERSION_MINOR "."
@@ -10,12 +20,35 @@ const char* notcurses_version(void){
   return NOTCURSES_VERSION;
 }
 
-int notcurses_init(void){
-  int ret = 0;
+int notcurses_term_dimensions(notcurses* n, int* rows, int* cols){
+  struct winsize ws;
+  int i = ioctl(n->ttyfd, TIOCGWINSZ, &ws);
+  if(i < 0){
+    fprintf(stderr, "TIOCGWINSZ failed on %d (%s)\n", n->ttyfd, strerror(errno));
+    return -1;
+  }
+  *rows = ws.ws_row;
+  *cols = ws.ws_col;
+  return 0;
+}
+
+notcurses* notcurses_init(void){
+  notcurses* ret = malloc(sizeof(*ret));
+  if(ret == NULL){
+    return ret;
+  }
   return ret;
 }
 
-int notcurses_stop(void){
+int notcurses_stop(notcurses* nc){
   int ret = 0;
+  if(nc){
+    if(close(nc->ttyfd)){
+      fprintf(stderr, "Error closing TTY file descriptor %d (%s)\n",
+              nc->ttyfd, strerror(errno));
+      ret = -1;
+    }
+    free(nc);
+  }
   return ret;
 }

tests/notcurses.cpp

@@ -1,7 +1,28 @@
+#include <string>
+#include <cstdlib>
 #include <notcurses.h>
 #include "main.h"
 
 TEST(Notcurses, BasicLifetime) {
-  ASSERT_EQ(0, notcurses_init());
-  EXPECT_EQ(0, notcurses_stop());
+  struct notcurses* nc = notcurses_init();
+  ASSERT_NE(nullptr, nc);
+  EXPECT_EQ(0, notcurses_stop(nc));
+}
+
+TEST(Notcurses, TermDimensions) {
+  struct notcurses* nc = notcurses_init();
+  int x, y;
+  ASSERT_NE(nullptr, nc);
+  EXPECT_EQ(0, notcurses_term_dimensions(nc, &y, &x));
+  auto stry = getenv("LINES");
+  if(stry){
+    auto envy = std::stoi(stry, nullptr);
+    EXPECT_EQ(envy, y);
+  }
+  auto strx = getenv("COLUMNS");
+  if(stry){
+    auto envx = std::stoi(strx, nullptr);
+    EXPECT_EQ(envx, x);
+  }
+  EXPECT_EQ(0, notcurses_stop(nc));
 }