Strip ansi escape sequences from subcommand output when not writing to a smart terminal.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/util.cc b/src/util.cc
index dbf7566..5f5d8dc 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -255,3 +255,31 @@ string GetLastErrorString() {
   return msg;
 }
 #endif
+
+static bool islatinalpha(int c) {
+  // isalpha() is locale-dependent.
+  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
+}
+
+string StripAnsiEscapeCodes(const string& in) {
+  string stripped;
+  stripped.reserve(in.size());
+
+  for (size_t i = 0; i < in.size(); ++i) {
+    if (in[i] != '\33') {
+      // Not an escape code.
+      stripped.push_back(in[i]);
+      continue;
+    }
+
+    // Only strip CSIs for now.
+    if (i + 1 >= in.size()) break;
+    if (in[i + 1] != '[') continue;  // Not a CSI.
+    i += 2;
+
+    // Skip everything up to and including the next [a-zA-Z].
+    while (i < in.size() && !islatinalpha(in[i]))
+      ++i;
+  }
+  return stripped;
+}