MQTT disecting topic with sscanf, a little guidance needed

Projects Programming
1

Hi Folks

I have a MQQT received topic:

cmnd/20/Output/17 received by my a callback as I'm subscribed to cmnd/20/+ via broker

I can successfully extract the integers needed with: ie 20 and 17

sscanf(topic,"%[^/]/%d/%[^/]/%d",&tempInt,&OutputNumber);

tempInt = 20
OutputNumber = 17

What I want to do is also extract the text also into variables....

sscanf(topic,"%s[^/]/%d[^/]/%s[^/]/%d",tempStr,&tempInt,tempStr1,&OutputNumber);

regex should discard all "/"

this doesnt extract the data and screws up tempInt and OutputNumber...I've tried all different permutations here I can think of....

I'd appreciate a hint as to where I'm going wrong.....

Thankyou..pete

2

You could use strtok (see here and here) to break the string into substrings, then process each substring

3

Hi there, yes I could use a different command and not learn how to use sscanf properly. I'd prefer to persist with a little guidance on this specific command...

Thankyou...Pete

4

Sorry for my deleted reply

You have

sscanf(topic,"%s[^/]

try

sscanf(topic,"%[^/]s

5

Thanks for the reply

sscanf(topic,"%[^/]s/%d/%[^/]s/%d",tempStr,&tempInt,tempStr1,&OutputNumber)

parses out cmnd for tempStr so thats an improvement HOWEVER the rest of the values are not parsed correctly.

So you got me on the right track

sscanf(topic,"%[^/]/%d/%[^/]/%d",tempStr,&tempInt,tempStr1,&OutputNumber);

That works......I would have thought I needed a %s for the string however with it, fail.. Removing the s for string, it works....

Weired but thankyou !!!

Pete