Implement TERMINAL_DIMENSIONS op for the terminal device, CE add terminfo command

ce/Makefile

@@ -5,7 +5,7 @@ $(eval $(call add_lib,libprocess))
 $(eval $(call add_lib,libaux))
 $(eval $(call add_lib,libarena))
 $(eval $(call add_lib,libioutil))
-$(eval $(call add_include,libterminal))
+$(eval $(call add_lib,libterminal))
 $(eval $(call add_include,libkb))
 
 cflags += -DPRINTF_INCLUDE_CONFIG_H=1

ce/interp.c

@@ -15,6 +15,7 @@
 #include <str_status.h>
 #include <string.h>
 #include <system.h>
+#include <terminal.h>
 
 static bool run = true;
 
@@ -51,6 +52,12 @@ static void mkfile (struct context* context, char** file_paths, size_t files_cou
   }
 }
 
+static void terminfo (struct context* context) {
+  size_t cols = 0, rows = 0;
+  terminal_dimensions (&cols, &rows);
+  cprintf (context, "%zu x %zu\n", cols, rows);
+}
+
 static void mkdir (struct context* context, char** dir_paths, size_t dirs_count) {
   char volume[VOLUME_MAX];
   const char* path;
@@ -248,6 +255,7 @@ static void help (struct context* context) {
   cprintf (context, "mkdir        <directory path>\n");
   cprintf (context, "rm           <path>\n");
   cprintf (context, "edit         <path>\n");
+  cprintf (context, "terminfo\n");
   cprintf (context, "quit\n");
 }
 
@@ -286,6 +294,8 @@ static void execute_cmd (struct ast_cmd* cmd, struct context* context) {
     rm (context, cmd->args, cmd->arg_count);
   } else if (strcmp (cmd->name, "edit") == 0) {
     edit (context, cmd->args[0]);
+  } else if (strcmp (cmd->name, "terminfo") == 0) {
+    terminfo (context);
   } else {
     char volume[VOLUME_MAX];
     const char* path;