CCS's Non-Standard Functions

haxan7 · Joined: 27 Jul 2013 Posts: 79

Many of the standard C functions are implemented in a very non-standard way by CCS.
For example:
isspace() returns true for only ' ' and not for tabs and line feeds.
atoi does not skip the spaces in the string before parsing, etc etc.

I understand that it is implemented this way for optimizations for limited memory and processing capabilities of pic.

My questions is, how do power users deal with this without having to spend hours debugging the code only to find the problem is with ccs's implementation of functions?

Also is there a way to override these functions without changing the names of functions to keep code portable and easy to understand.

temtronic · Posted: Mon Jul 13, 2015 2:08 pm

re: isspace() function

Works correctly for me. 'tabs(0x9)' and 'linefeeds(0x0a)' are NOT 'spaces'( 0x40).
My 'old school' thinking is that if another implementation says a 'linefeed' is 'space' then that's wrong ! THAT would really screw up 'parsing' and 'flagging'!

As for 'custom' functions.... just cut your own and call them something like .. 'my_isspace() say if you want to include tabs and linefeeds as spaces.

By using the prefix of 'my_' it'll remind you that it's YOUR function not the CCS one.

Jay

Ttelmah · Joined: 11 Mar 2010 Posts: 19590

The 'correct' definition for isspace, is 'space', 'tab' or 'newline'.

CCS implements it as space only.

You can define your own versions for any of the character match macros using isamong. They are in ctype.h.
They are only convenience macros, not functions.

You can add white space skipping to atol if required, but generally since if you are looking for a number to convert you will be searching for the number first it makes no difference. It's properly documented in the CCS manual.

The definitions for atol etc., are all in stdlib, and if you want leading suppression just add:

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

Here is a quick way to replace the CCS isspace() with a macro.
Just fill in the isamong() parameter list with whatever characters
you want to consider as spaces. The expanded version of isspace()
is shown below, but you could edit the macro to use the traditional
characters as Ttelmah says.

The isspace() macro is the #define statement. Most of the code below
is a test program. It has the following output in MPLAB 8.92 simulator: