sprintf %s not working as expected

[pmuldoon]

compliler v5.074
PIC 18F66K22

I seem to be having trouble with the %s format specifier. I am trying to fix the string length so not to overflow my tiny LCD display line memory of 20 characters. Using %5s should pad the string, %5.5s should truncate or pad as necessary to get 5 chars. Neither seem to work as expected. In all cases the entire length of the string is inserted as if it were just %s.

I've reduced the problem down to a simple snippet I've inserted into main() and have been testing with the PICSIM tool.

[Ttelmah]

It is a compiler limitation. Like -, which doesn't work either.
You just have to truncate the string before printing. Either just add a null terminator at character 6, or use strncpy to copy it into another array.

[pmuldoon]

Understandable.
I can work around it.
Thanks,

[pmuldoon]

I guess it would have been nice if the compiler could at least throw an error if there is anything between the '%' and 'S' since it doesn't support a standard feature. Even just a syntax error would have been helpful.

[Ttelmah]

Yes.

In fact given how close to fully working the compiler is now, these are both 'lacks' that CCS might like to consider correcting. Worth pointing this out to them.

[jeremiah]

I made a hack of an snprintf function if you want a general solution.

https://www.ccsinfo.com/forum/viewtopic.php?t=53652&highlight=snprintf

Note that it currently returns the number of characters it would have written had max not held it back (for debugging purposes). I did this since you can always call strlen on the result to see the actual number of chars written.

It should always append a null, so if you specify a max of 5, it will do 4 characters and a null character.