diff options
| -rw-r--r-- | src/nix/progress-bar.cc | 45 |
1 files changed, 41 insertions, 4 deletions
diff --git a/src/nix/progress-bar.cc b/src/nix/progress-bar.cc index a692250f826d..cd5a8fca26ee 100644 --- a/src/nix/progress-bar.cc +++ b/src/nix/progress-bar.cc @@ -24,6 +24,44 @@ static uint64_t getI(const std::vector<Logger::Field> & fields, size_t n) return fields[n].i; } +/* Truncate a string to 'width' printable characters. ANSI escape + sequences are copied but not included in the character count. Also, + tabs are expanded to spaces. */ +static std::string ansiTruncate(const std::string & s, int width) +{ + if (width <= 0) return s; + + std::string t; + size_t w = 0; + auto i = s.begin(); + + while (w < (size_t) width && i != s.end()) { + if (*i == '\e') { + t += *i++; + if (i != s.end() && *i == '[') { + t += *i++; + while (i != s.end() && (*i < 0x40 || *i > 0x7e)) { + t += *i++; + } + if (i != s.end()) t += *i++; + } + } + + else if (*i == '\t') { + t += ' '; w++; + while (w < (size_t) width && w & 8) { + t += ' '; w++; + } + } + + else { + t += *i++; w++; + } + } + + return t; +} + class ProgressBar : public Logger { private: @@ -89,7 +127,7 @@ public: void log(State & state, Verbosity lvl, const std::string & s) { - writeToStderr("\r\e[K" + s + "\n"); + writeToStderr("\r\e[K" + s + ANSI_NORMAL "\n"); update(state); } @@ -207,7 +245,7 @@ public: void update(State & state) { - std::string line = "\r"; + std::string line; std::string status = getStatus(state); if (!status.empty()) { @@ -232,8 +270,7 @@ public: } } - line += "\e[K"; - writeToStderr(std::string(line, 0, width - 1)); + writeToStderr("\r" + ansiTruncate(line, width) + "\e[K"); } std::string getStatus(State & state) |