Add support for changing the `diff` command via an environment variable

While the file arguments remain fixed the actual `diff` application and its output style can be changed using the `CHANGE_LOG_DIFF_CMD` environment variable.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/change_log.cc b/src/change_log.cc
index c592f20..44a6046 100644
--- a/src/change_log.cc
+++ b/src/change_log.cc
@@ -23,7 +23,13 @@ void init() {
 		logger   = std::make_unique<utility::Logger>(STDERR_FILENO);
 	}
 
-	tracker = std::make_unique<tracking::ChangeTracker>(logger.get());
+	if ( getenv("CHANGE_LOG_DIFF_CMD") != NULL ) {
+		tracker = std::make_unique<tracking::ChangeTracker>(
+			logger.get(), getenv("CHANGE_LOG_DIFF_CMD")
+		);
+	} else {
+		tracker = std::make_unique<tracking::ChangeTracker>(logger.get());
+	}
 }
 
 ssize_t write(int fd, const void* buffer, size_t count) {