Add a helper for formatted output

For now this just uses isatty(), but we might
allow overriding this with an environment variable
in the future.

common/flatpak-utils.c

@@ -506,6 +506,12 @@ flatpak_is_in_sandbox (void)
   return in_sandbox == 1;
 }
 
+gboolean
+flatpak_fancy_output (void)
+{
+        return isatty (STDOUT_FILENO);
+}
+
 const char *
 flatpak_get_bwrap (void)
 {

common/flatpak-utils.h

@@ -65,6 +65,8 @@ const char * flatpak_path_match_prefix (const char *pattern,
 
 gboolean flatpak_is_in_sandbox (void);
 
+gboolean flatpak_fancy_output (void);
+
 const char * flatpak_get_arch (void);
 const char ** flatpak_get_arches (void);
 gboolean flatpak_is_linux32_arch (const char *arch);