mosquitto_sub now supports extra format specifiers.

These are for field width and precision for some parameters.

ChangeLog.txt

@@ -56,6 +56,8 @@ Clients:
   of received messages to be printed.
 - mosquitto_sub %j and %J timestamps are now in a ISO 8601 compatible format.
 - mosquitto_pub now sends 0 length files without an error when using `-f`.
+- mosquitto_sub now supports extra format specifiers for field width and
+  precision for some parameters.
 
 
 1.6.9 - 20200227

client/client_shared.c

@@ -55,6 +55,45 @@ static int check_format(const char *str)
 				fprintf(stderr, "Error: Incomplete format specifier.\n");
 				return 1;
 			}else{
+				if(str[i+1] == '0' || str[i+1] == '-'){
+					/* Flag characters */
+					i++;
+					if(i == len-1){
+						// error
+						fprintf(stderr, "Error: Incomplete format specifier.\n");
+						return 1;
+					}
+				}
+
+				/* Field width */
+				while(str[i+1] >= '0' && str[i+1] <= '9'){
+					i++;
+					if(i == len-1){
+						// error
+						fprintf(stderr, "Error: Incomplete format specifier.\n");
+						return 1;
+					}
+				}
+
+				if(str[i+1] == '.'){
+					/* Precision specifier */
+					i++;
+					if(i == len-1){
+						// error
+						fprintf(stderr, "Error: Incomplete format specifier.\n");
+						return 1;
+					}
+					/* Precision */
+					while(str[i+1] >= '0' && str[i+1] <= '9'){
+						i++;
+						if(i == len-1){
+							// error
+							fprintf(stderr, "Error: Incomplete format specifier.\n");
+							return 1;
+						}
+					}
+				}
+
 				if(str[i+1] == '%'){
 					// Print %, ignore
 				}else if(str[i+1] == 'A'){

client/sub_test_fixed_width

@@ -0,0 +1,59 @@
+LD_LIBRARY_PATH=../lib ./mosquitto_sub \
+	-h test.mosquitto.org \
+	--retained-only \
+	--remove-retained \
+	-t FW/# \
+	-W 1>/dev/null 2>/dev/null
+
+LD_LIBRARY_PATH=../lib ./mosquitto_pub \
+	-h test.mosquitto.org \
+	-D publish content-type "application/json" \
+	-D publish message-expiry-interval 360000 \
+	-D publish payload-format-indicator 1 \
+	-D publish response-topic response-topic \
+	-m ABCDEFGHIJKLMNOPQRSTUVWXYZ \
+	-q 2 \
+	-r \
+	-t FW/truncate \
+	-V 5
+
+LD_LIBRARY_PATH=../lib ./mosquitto_pub \
+	-h test.mosquitto.org \
+	-D publish content-type "null" \
+	-D publish message-expiry-interval 3600 \
+	-D publish payload-format-indicator 1 \
+	-D publish response-topic r-t \
+	-m Off \
+	-q 2 \
+	-r \
+	-t FW/expire \
+	-V 5
+
+LD_LIBRARY_PATH=../lib ./mosquitto_pub \
+	-h test.mosquitto.org \
+	-D publish payload-format-indicator 1 \
+	-D publish response-topic rt \
+	-m Offline \
+	-q 2 \
+	-r \
+	-t FW/1 \
+	-V 5
+
+LD_LIBRARY_PATH=../lib ./mosquitto_sub \
+	-h test.mosquitto.org \
+	-C 3 \
+	-F "| %10t | %-10t | %7x | %-7x | %08x | %7X | %-7X | %08X | %8p | %-8p | %3m | %-3m | %03m | %3l | %-3l | %03l | %2F | %-2F | %02F | %5C | %-5C | %5E | %-5E | %05E | %5A | %5R | %-5R |" \
+	-q 2 \
+	-t 'FW/#' \
+	-V 5
+
+echo
+
+LD_LIBRARY_PATH=../lib ./mosquitto_sub \
+	-h test.mosquitto.org \
+	-C 3 \
+	-F "| %10.10t | %.5t | %-10.10t | %7x | %-7x | %08x | %7X | %-7X | %08X | %8p | %-8p | %3m | %-3m | %03m | %3l | %-3l | %03l | %2F | %-2F | %02F | %5C | %-5C | %5E | %-5E | %05E | %5.5A | %5.5R | %-5.5R |" \
+	-q 2 \
+	-t 'FW/#' \
+	-V 5
+

man/Makefile

@@ -50,32 +50,32 @@ uninstall :
 	-rm -f "${DESTDIR}${mandir}/man7/mosquitto-tls.7"
 	-rm -f "${DESTDIR}${mandir}/man3/libmosquitto.3"
 
-mosquitto.8 : mosquitto.8.xml
-	$(XSLTPROC) $^
+mosquitto.8 : mosquitto.8.xml manpage.xsl
+	$(XSLTPROC) $<
 
 mosquitto.conf.5 : mosquitto.conf.5.xml manpage.xsl
 	$(XSLTPROC) $<
 
-mosquitto_passwd.1 : mosquitto_passwd.1.xml
-	$(XSLTPROC) $^
+mosquitto_passwd.1 : mosquitto_passwd.1.xml manpage.xsl
+	$(XSLTPROC) $<
 
-mosquitto_pub.1 : mosquitto_pub.1.xml
-	$(XSLTPROC) $^
+mosquitto_pub.1 : mosquitto_pub.1.xml manpage.xsl
+	$(XSLTPROC) $<
 
-mosquitto_sub.1 : mosquitto_sub.1.xml
-	$(XSLTPROC) $^
+mosquitto_sub.1 : mosquitto_sub.1.xml manpage.xsl
+	$(XSLTPROC) $<
 
-mosquitto_rr.1 : mosquitto_rr.1.xml
-	$(XSLTPROC) $^
+mosquitto_rr.1 : mosquitto_rr.1.xml manpage.xsl
+	$(XSLTPROC) $<
 
-mqtt.7 : mqtt.7.xml
-	$(XSLTPROC) $^
+mqtt.7 : mqtt.7.xml manpage.xsl
+	$(XSLTPROC) $<
 
-mosquitto-tls.7 : mosquitto-tls.7.xml
-	$(XSLTPROC) $^
+mosquitto-tls.7 : mosquitto-tls.7.xml manpage.xsl
+	$(XSLTPROC) $<
 
-libmosquitto.3 : libmosquitto.3.xml
-	$(XSLTPROC) $^
+libmosquitto.3 : libmosquitto.3.xml manpage.xsl
+	$(XSLTPROC) $<
 
 html : *.xml
 	set -e; for m in *.xml; \

man/mosquitto_sub.1.xml

@@ -790,7 +790,7 @@ mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained</programlisting>
 	</refsect1>
 
 	<refsect1 id='outputformat'>
-		<title>Output format</title>
+		<title>Output Format</title>
 		<para>There are three ways of formatting the output from mosquitto_sub.
 			In all cases a new-line character is appended for each message
 			received unless the <option>-N</option> argument is passed to
@@ -824,6 +824,58 @@ mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained</programlisting>
 			character is <option>\</option>, which is used to input some
 			characters that would otherwise be difficult to enter.</para>
 
+		<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>
+			<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.
+					It will be ignored for other parameters. If used with the
+				<option>-</option> flag, the <option>0</option> flag will be
+					ignored.</para></listitem>
+				</varlistentry>
+
+				<varlistentry>
+					<term><option>-</option></term>
+					<listitem><para>The value will be left aligned to the field width,
+						padded with blanks. The default is right alignment, with either 0
+						or blank padding.</para></listitem>
+				</varlistentry>
+			</variablelist>
+		</refsect2>
+
+		<refsect2>
+			<title>Field width</title>
+                <para>
+                    Some of the MQTT related parameters can be formatted with an
+                    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.
+                </para>
+				<para>
+					For example <option>%10t</option> would set the minimum topic
+					field width to 10 characters.
+				</para>
+		</refsect2>
+
+		<refsect2>
+			<title>Maximum width</title>
+                <para>
+                    Some of the MQTT related parameters can be formatted with an
+                    option to set a maximum field width in a similar way to regular
+                    printf style formats. This applies to the options %C, %I, %R, %t.
+                </para>
+				<para>
+					For example <option>%10.10t</option> would set the minimum topic
+					field width to 10 characters, and the maximum topic width to 
+                    10 characters, i.e. the field will always be exactly 10
+                    characters long.
+				</para>
+		</refsect2>
+
 		<refsect2>
 			<title>MQTT related parameters</title>
 			<itemizedlist mark="circle">