Elide output in the middle when exceeding terminal width.

When building projects with long file paths, the rule name may
disappear since the output is elided on the left side.
So you no longer know whether you are compiling or linking.

I think the user is interested in both the rule name and the file name.

Eliding the output in the middle solves this problem.

1 files changed, 4 insertions, 3 deletions

diff --git a/src/build.cc b/src/build.cc
index 9adce8f..e72d9d7 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -156,9 +156,10 @@ void BuildStatus::PrintStatus(Edge* edge) {
     if ((ioctl(0, TIOCGWINSZ, &size) == 0) && size.ws_col) {
       const int kMargin = progress_chars + 3;  // Space for [xx/yy] and "...".
       if (to_print.size() + kMargin > size.ws_col) {
-        int substr = std::min(to_print.size(),
-                              to_print.size() + kMargin - size.ws_col);
-        to_print = "..." + to_print.substr(substr);
+        int elide_size = (size.ws_col - kMargin) / 2;
+        to_print = to_print.substr(0, elide_size)
+          + "..."
+          + to_print.substr(to_print.size() - elide_size, elide_size);
       }
     }
   }