New option "--stats", to show a line of statistics about the transfer once it has ended (issue #49).

src/include/config.h.in

@@ -73,6 +73,9 @@
 /* Define to 1 if you have the <locale.h> header file. */
 #undef HAVE_LOCALE_H
 
+/* Define to 1 if you have the <math.h> header file. */
+#undef HAVE_MATH_H
+
 /* Define to 1 if you have the `memcpy' function. */
 #undef HAVE_MEMCPY
 
@@ -112,6 +115,9 @@
 /* Define to 1 if you have the `splice' function. */
 #undef HAVE_SPLICE
 
+/* Define to 1 if you have the `sqrtl' function. */
+#undef HAVE_SQRTL
+
 /* Define to 1 if stdbool.h conforms to C99. */
 #undef HAVE_STDBOOL_H
 

src/include/options.h

@@ -74,6 +74,7 @@ struct opts_s {
 	bool sync_after_write;         /* set if we sync after every write */
 	bool direct_io;                /* set if O_DIRECT is to be used */
 	bool discard_input;            /* set to write nothing to output */
+	bool show_stats;	       /* set to write statistics at the end */
 	bool width_set_manually;       /* width was set manually, not detected */
 	bool height_set_manually;      /* height was set manually, not detected */
 };

src/include/pv-internal.h

@@ -134,6 +134,7 @@ struct pvstate_s {
 		bool direct_io_changed;          /* set when direct_io is changed */
 		bool no_splice;                  /* never use splice() */
 		bool discard_input;              /* write nothing to stdout */
+		bool show_stats;		 /* show statistics on exit */
 		bool width_set_manually;	 /* width was set manually, not detected */
 		bool height_set_manually;	 /* height was set manually, not detected */
 	} control;
@@ -219,6 +220,12 @@ struct pvstate_s {
 		long double prev_trans;		 /* amount transferred since last rate calculation */
 		long double current_avg_rate;    /* current average rate over last history intervals */
 
+		long double rate_min;		 /* minimum measured transfer rate */
+		long double rate_max;		 /* maximum measured transfer rate */
+		long double rate_sum;		 /* sum of all measured transfer rates */
+		long double ratesquared_sum;	 /* sum of the squares of each transfer rate */
+		unsigned long measurements_taken; /* how many times the rate was measured */
+
 		/* Keep track of progress over last intervals to compute current average rate. */
 		/*@null@*/ struct {	 /* state at previous intervals (circular buffer) */
 			long double elapsed_sec;	/* time since start of transfer */

src/include/pv.h

@@ -172,6 +172,7 @@ extern void pv_state_set_format(pvstate_t state, bool progress,
  */
 extern void pv_state_force_set(pvstate_t, bool);
 extern void pv_state_cursor_set(pvstate_t, bool);
+extern void pv_state_show_stats_set(pvstate_t, bool);
 extern void pv_state_numeric_set(pvstate_t, bool);
 extern void pv_state_wait_set(pvstate_t, bool);
 extern void pv_state_delay_start_set(pvstate_t, double);