Merge branch 'mlyszczek-add-float-format' into develop

client/client_shared.c

@@ -140,6 +140,12 @@ static int check_format(const char *str)
 #endif
 				}else if(str[i+1] == 'x' || str[i+1] == 'X'){
 					/* payload in hex */
+				}else if(str[i+1] == 'f' || str[i+1] == 'd'){
+					/* payload in float */
+#ifndef __STDC_IEC_559__
+					fprintf(stderr, "Error: Can't print float, missing __STDC_IEC_559__ standard support.\n");
+					return 1;
+#endif
 				}else{
 					fprintf(stderr, "Error: Invalid format specifier '%c'.\n", str[i+1]);
 					return 1;

client/sub_client_output.c

@@ -422,6 +422,42 @@ static void formatted_print_blank(char pad, int field_width)
 }
 
 
+#ifdef __STDC_IEC_559__
+static int formatted_print_float(const unsigned char *payload, int payloadlen, char format, char align, char pad, int field_width, int precision)
+{
+	float float_value;
+	double value;
+	if (format == 'f'){
+		if (sizeof(float_value) != payloadlen) {
+			return -1;
+		}
+		memcpy(&float_value, payload, sizeof(float_value));
+		value = float_value;
+	}else if(format == 'd'){
+		if (sizeof(value) != payloadlen) {
+			return -1;
+		}
+		memcpy(&value, payload, sizeof(value));
+	}
+
+	if(field_width == 0) {
+		printf("%.*f", precision, value);
+	}else{
+		if(align == '-'){
+			printf("%-*.*f", field_width, precision, value);
+		}else{
+			if(pad == '0'){
+				printf("%0*.*f", field_width, precision, value);
+			}else{
+				printf("%*.*f", field_width, precision, value);
+			}
+		}
+	}
+	return 0;
+}
+#endif
+
+
 static void formatted_print_int(int value, char align, char pad, int field_width)
 {
 	if(field_width == 0){
@@ -651,6 +687,20 @@ static void formatted_print_percent(const struct mosq_config *lcfg, const struct
 		case 'X':
 			write_payload(message->payload, message->payloadlen, 2, align, pad, field_width, precision);
 			break;
+
+#ifdef __STDC_IEC_559__
+		case 'f':
+			if(formatted_print_float(message->payload, message->payloadlen, 'f', align, pad, field_width, precision)) {
+				err_printf(lcfg, "requested float printing, but non-float data received");
+			}
+			break;
+
+		case 'd':
+			if(formatted_print_float(message->payload, message->payloadlen, 'd', align, pad, field_width, precision)) {
+				err_printf(lcfg, "requested double printing, but non-double data received");
+			}
+			break;
+#endif
 	}
 }
 

man/mosquitto_sub.1.xml

@@ -927,12 +927,12 @@ mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained</programlisting>
 
 		<refsect2>
 			<title>Flag characters</title>
-			<para>The parameters %A, %C, %E, %F, %I, %l, %m, %p, %R, %S, %t, %x, and %X can have optional flags immediately after the % character.</para>
+			<para>The parameters %A, %C, %E, %F, %I, %l, %m, %p, %R, %S, %t, %f, %d, %x, and %X can have optional flags immediately after the % character.</para>
 			<variablelist>
 				<varlistentry>
 					<term><option>0</option></term>
 					<listitem><para>The value should be zero padded.
-					This applies to the parameters %A, %E, %F, %l, %m, %S, %X, and %x.
+					This applies to the parameters %A, %E, %F, %l, %m, %S, %f, %d, %X, and %x.
 					It will be ignored for other parameters. If used with the
 				<option>-</option> flag, the <option>0</option> flag will be
 					ignored.</para></listitem>
@@ -954,7 +954,7 @@ mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained</programlisting>
                     option to set their field width in a similar way to regular
                     printf style formats, i.e. this sets the minimum width when
                     printing this parameter. This applies to the options %A, %C,
-                    %E, %F, %I, %l, %m, %p, %R, %S, %t, %x, %X.
+                    %E, %F, %I, %l, %m, %p, %R, %S, %t, %f, %d, %x, %X.
                 </para>
 				<para>
 					For example <option>%10t</option> would set the minimum topic
@@ -977,6 +977,28 @@ mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained</programlisting>
 				</para>
 		</refsect2>
 
+		<refsect2>
+			<title>Floating point number printing consideration</title>
+				<para>
+					Mosquitto supports only IEEE754 floating point standard as
+					described in Annex F of ISO/IEC 9899:1999. Don't try to
+					use %f or %d if publisher's platform uses different
+					floating point representation standard than IEEE754 or you
+					will get invalid data. If you are unsure what floating
+					representation your platform is using, then it's most
+					likely IEEE754. If you get malformed and unexpected values,
+					check if float number in payload from publisher is encoded
+					in IEEE754.
+				</para>
+				<para>
+					If want to print floats, make sure you subscribe only
+					to topics that send only IEEE754 formatted floats.
+					Mosquitto is very strict about floats and if anything
+					that is not float is received, an error message will
+					be printed.
+				</para>
+		</refsect2>
+
 		<refsect2>
 			<title>MQTT related parameters</title>
 			<itemizedlist mark="circle">
@@ -1000,6 +1022,8 @@ mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained</programlisting>
 				<listitem><para><option>%t</option> the message topic.</para></listitem>
 				<listitem><para><option>%x</option> the payload with each byte as a hexadecimal number (lower case).</para></listitem>
 				<listitem><para><option>%X</option> the payload with each byte as a hexadecimal number (upper case).</para></listitem>
+				<listitem><para><option>%f</option> the payload is treated as 4byte IEEE754 float.</para></listitem>
+				<listitem><para><option>%d</option> the payload is treated as 8byte IEEE754 float (double).</para></listitem>
 			</itemizedlist>
 		</refsect2>