From 863b5d814443eb791c2dd07250ac0ae29054adb0 Mon Sep 17 00:00:00 2001
From: John Wiegley <johnw@newartisans.com>
Date: Wed, 4 Feb 2009 20:46:08 -0400
Subject: Added proper handling of SIGINT (C-c) and SIGPIPE (pager quits).

---
 src/handler.h |  4 +++-
 src/main.cc   | 20 ++++++++++----------
 src/utils.cc  | 17 +++++++++++++++++
 src/utils.h   | 22 ++++++++++++++++++++++
 4 files changed, 52 insertions(+), 11 deletions(-)

(limited to 'src')

diff --git a/src/handler.h b/src/handler.h
index 8f4d71b9..bfb1b08f 100644
--- a/src/handler.h
+++ b/src/handler.h
@@ -78,8 +78,10 @@ public:
       handler->flush();
   }
   virtual void operator()(T& item) {
-    if (handler.get())
+    if (handler.get()) {
+      check_for_signal();
       (*handler.get())(item);
+    }
   }
 };
 
diff --git a/src/main.cc b/src/main.cc
index 221374c0..06ce8563 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -57,11 +57,6 @@ namespace {
     return s;
   }
 
-  void sigint_handler(int sig)
-  {
-    throw std::logic_error("Interrupted by user (use Control-D to quit)");
-  }
-
   strings_list split_arguments(char * line)
   {
     strings_list args;
@@ -177,12 +172,16 @@ namespace {
     catch (const std::exception& err) {
       std::cout.flush();		// first display anything that was pending
 
-      // Display any pending error context information
-      string context = error_context();
-      if (! context.empty())
-	std::cerr << context << std::endl;
+      if (caught_signal == NONE_CAUGHT) {
+	// Display any pending error context information
+	string context = error_context();
+	if (! context.empty())
+	  std::cerr << context << std::endl;
     
-      std::cerr << "Error: " << err.what() << std::endl;
+	std::cerr << "Error: " << err.what() << std::endl;
+      } else {
+	caught_signal = NONE_CAUGHT;
+      }
     }
     catch (int _status) {
       status = _status;		// used for a "quick" exit, and is used only
@@ -226,6 +225,7 @@ int main(int argc, char * argv[], char * envp[])
     session->option_version(*session);
     
     std::signal(SIGINT, sigint_handler);
+    std::signal(SIGPIPE, sigpipe_handler);
 
 #ifdef HAVE_LIBEDIT
 
diff --git a/src/utils.cc b/src/utils.cc
index 74a8ea6c..d4b05fec 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -626,6 +626,23 @@ void finish_timer(const char * name)
 
 #endif // LOGGING_ON && TIMERS_ON
 
+/**********************************************************************
+ *
+ * Signal handlers
+ */
+
+caught_signal_t caught_signal = NONE_CAUGHT;
+
+void sigint_handler(int sig)
+{
+  caught_signal = INTERRUPTED;
+}
+
+void sigpipe_handler(int sig)
+{
+  caught_signal = PIPE_CLOSED;
+}
+
 /**********************************************************************
  *
  * General utility functions
diff --git a/src/utils.h b/src/utils.h
index 41142624..23ae10c7 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -475,6 +475,28 @@ void finish_timer(const char * name);
 #include "stream.h"
 #include "pushvar.h"
 
+enum caught_signal_t {
+  NONE_CAUGHT,
+  INTERRUPTED,
+  PIPE_CLOSED
+};
+
+extern caught_signal_t caught_signal;
+
+void sigint_handler(int sig);
+void sigpipe_handler(int sig);
+
+inline void check_for_signal() {
+  switch (caught_signal) {
+  case NONE_CAUGHT:
+    break;
+  case INTERRUPTED:
+    throw std::runtime_error("Interrupted by user (use Control-D to quit)");
+  case PIPE_CLOSED:
+    throw std::runtime_error("Pipe terminated");
+  }
+}
+
 /**
  * @name General utility functions
  */
-- 
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