Error in elbot.c

[v0id]

I'm not sure if this is the correct place to post this, and it may be frowned upon, but for those of you that have created a bot with redknight...

 

I've ran into this problem while compiling in DEV-C++ 4.9.9.2

 

in elbot.c

 

elbot.c: In function `process_text_message':

elbot.c:250: error: assignment of read-only location

 

Line250

data = tolower(data);

 

ERROR : assignment of read-only location

 

data is declared like this:

 

Line240

void process_text_message(const char *data, int PM) {

 

---------------

 

If anyone could shed some light, I would appreciate it -- otherwise, I'm sure I'll figure it out in a few. But a quickfix from someone that has done it before would be great!!

 

Thanks in advance!

[Bongo]

You can't change a variable that's declared with the "const" keyword. Either remove it or create a pointer to data like so:

 

char *p = data;

 

then...

 

p[i] = tolower(p[i])

 

would not cause an error.

[v0id]

You can't change a variable that's declared with the "const" keyword. Either remove it or create a pointer to data like so:

 

char *p = data;

 

then...

 

p[i] = tolower(p[i])

 

would not cause an error.

 

 

Yep! that worked. ...among fixing other things... lol. well, at least this gives me a template to work from. now the real fun begins. Thanks for the pointer (no pun intended)!

Edited April 24, 2006 by v0id

[crusadingknight]

I'm not sure if this is the correct place to post this, and it may be frowned upon, but for those of you that have created a bot with redknight...

 

I wouldn't recommend it, unless you need a guard bot. The source is a bit of a mess, though I'm slowly tacking on some proper architecture, and deadheading the worst of it (ie. I have, though not yet committed, the code to move from the weird old hacked lists architecture to a proper hash list format.) Still, in the interim... storebot may be the better choice. (Which, I believe, is based almost entirely off of Bongo's work.).

Edited April 25, 2006 by crusadingknight

[Bongo]

Which, I believe, is based almost entirely off of Bongo's work.

 

No need to give me credit for that monstrosity :-). I abandoned that project shortly after starting it. If you're looking for a decent store bot, look no further than somewhere else.

[trollson]

You can't change a variable that's declared with the "const" keyword. Either remove it or create a pointer to data like so:

char *p = data;

then...

p[i] = tolower(p[i])

would not cause an error.

 

However it may cause a SEGV later.

 

You don't know where 'data' came from, and cannot make presumptions. It may point to read-only memory, such as a string literal. eg:

const char *data = "Hello World";

These are now placed in read-only memory, and attempting to change them will result in a runtime error/crash/SEGV.

 

You cannot cast away your problems, you are just hiding the bug for later.

Options are:

1. Change the function declaration. This is bad because it requires all users to re-evaluate their use of it, but is necessary if the side-effect of calling this function is to lower-case the contents of 'data'.
   
2. Or take a local mutable copy of the data and use that instead. In which case the case changes will not be passed out of the function.