Function source_origin

src/os/linux/bash_history.cpp:534–537

The `source` column is " / " where origin is "heap" or a real history filename (e.g. "bash/.bash_history", "zsh/heap").

// The `source` column is "<shell>/<origin>" where origin is "heap" or a real
// history filename (e.g. "bash/.bash_history", "zsh/heap").
std::string source_origin(const ShellCmd& e) {
    auto slash = e.source.find('/');
    return slash == std::string::npos ? std::string() : e.source.substr(slash + 1);
}

bool high_confidence_history(const ShellCmd& e) {
    // Explicit confidence in the note wins.