Add some utilities for exception handling and detecting whether stderr is a terminal

README.md

@@ -145,7 +145,7 @@ namespace cpptrace {
         void print() const;
         void print(std::ostream& stream) const;
         void print(std::ostream& stream, bool color) const;
-        std::string to_string() const;
+        std::string to_string(bool color = false) const;
         void clear();
         bool empty() const noexcept;
         /* operator<<(ostream, ..), std::format support, and iterators exist for this object */
@@ -224,10 +224,17 @@ or wether they're rethrown to the caller.
 speed is prioritized. If using this function, set the cache mode at the very start of your program before any traces are
 performed.
 
+`cpptrace::isatty` and the fileno definitions are useful for deciding whether to use color when printing stack taces.
+
 ```cpp
 namespace cpptrace {
     std::string demangle(const std::string& name);
     void absorb_trace_exceptions(bool absorb);
+    bool isatty(int fd);
+
+    extern const int stdin_fileno;
+    extern const int stderr_fileno;
+    extern const int stdout_fileno;
 
     enum class cache_mode {
         // Only minimal lookup tables

include/cpptrace/cpptrace.hpp

@@ -2,7 +2,6 @@
 #define CPPTRACE_HPP
 
 #include <cstdint>
-#include <cstdio>
 #include <exception>
 #include <ostream>
 #include <string>
@@ -103,7 +102,7 @@ namespace cpptrace {
         CPPTRACE_API void print(std::ostream& stream, bool color) const;
         CPPTRACE_API void clear();
         CPPTRACE_API bool empty() const noexcept;
-        CPPTRACE_API std::string to_string() const;
+        CPPTRACE_API std::string to_string(bool color = false) const;
         CPPTRACE_API friend std::ostream& operator<<(std::ostream& stream, const stacktrace& trace);
 
         using iterator = std::vector<stacktrace_frame>::iterator;
@@ -127,8 +126,13 @@ namespace cpptrace {
 
     // utilities:
     CPPTRACE_API std::string demangle(const std::string& name);
+    CPPTRACE_API bool isatty(int fd);
     CPPTRACE_API void absorb_trace_exceptions(bool absorb);
 
+    CPPTRACE_API extern const int stdin_fileno;
+    CPPTRACE_API extern const int stderr_fileno;
+    CPPTRACE_API extern const int stdout_fileno;
+
     enum class cache_mode {
         // Only minimal lookup tables
         prioritize_memory,

src/cpptrace.cpp

@@ -3,6 +3,7 @@
 #include <atomic>
 #include <cstddef>
 #include <cstdint>
+#include <cstdio>
 #include <iomanip>
 #include <iostream>
 #include <sstream>
@@ -233,9 +234,9 @@ namespace cpptrace {
     }
 
     CPPTRACE_API
-    std::string stacktrace::to_string() const {
+    std::string stacktrace::to_string(bool color) const {
         std::ostringstream oss;
-        print(oss, false, false);
+        print(oss, color, false);
         return std::move(oss).str();
     }
 
@@ -318,6 +319,15 @@ namespace cpptrace {
         return detail::demangle(name);
     }
 
+    CPPTRACE_API
+    bool isatty(int fd) {
+        return detail::isatty(fd);
+    }
+
+    CPPTRACE_API const int stdin_fileno = detail::fileno(stdin);
+    CPPTRACE_API const int stdout_fileno = detail::fileno(stdout);
+    CPPTRACE_API const int stderr_fileno = detail::fileno(stderr);
+
     namespace detail {
         std::atomic_bool absorb_trace_exceptions(true); // NOSONAR
         std::atomic<enum cache_mode> cache_mode(cache_mode::prioritize_speed); // NOSONAR

src/platform/utils.hpp

@@ -22,12 +22,30 @@
 
 #if IS_WINDOWS
  #include <windows.h>
+ #include <io.h>
 #else
  #include <sys/stat.h>
+ #include <unistd.h>
 #endif
 
 namespace cpptrace {
 namespace detail {
+    inline bool isatty(int fd) {
+        #if IS_WINDOWS
+         return _isatty(fd);
+        #else
+         return ::isatty(fd);
+        #endif
+    }
+
+    inline int fileno(FILE* stream) {
+        #if IS_WINDOWS
+         return _fileno(stream);
+        #else
+         return ::fileno(stream);
+        #endif
+    }
+
     inline std::vector<std::string> split(const std::string& str, const std::string& delims) {
         std::vector<std::string> vec;
         size_t old_pos = 0;

test/demo.cpp

@@ -6,8 +6,8 @@
 #include <string>
 
 void trace() {
-    cpptrace::absorb_trace_exceptions(false);
     cpptrace::generate_trace().print();
+    throw cpptrace::exception_with_message("foobar");
 }
 
 void foo(int n) {
@@ -35,5 +35,8 @@ int main() try {
     cpptrace::absorb_trace_exceptions(false);
     function_one(0);
 } catch(cpptrace::exception& e) {
-    std::cerr << e.what();
+    std::cerr << "Error: "
+              << e.get_raw_what()
+              << '\n';
+    e.get_trace().print(std::cerr, cpptrace::isatty(cpptrace::stderr_fileno));
 }