more string checking

[tomchesley]

I need a way to determine a text string if it is ok or not
examples
id's can be any hex number up to ffffffff
a = bad missing ^id
^0 = bad missing name before ^id
Tron^0 =0k valid name and id
John^48d7cf5 =ok valid name an id
Tonka^0^MAKIABDCCBOC/ZONA.SIT/circuit/+/4/1,8 = ok hosting game
Everett^48d7cf5^MJBFOLJFBILF//rally/+/1/1,8 =ok hosting game
Tonka^0^MJBFOLJFBILF =ok joined game

the pointer that contains this string is source_p->info
i can check for the len of this with

nlen = strlen(source_p->info);

but not sure how i can check for the ^ then the contents after or before

any hints?

 

[xwb]

Try

char *before, *after;

before = strtok (source_p->info, "^");
after  = strtok (NULL, "^");

before is the string before ^
after is the string after ^

 

[tomchesley]

that works but it changes the original value
I tried

char *before, *after, *hold;
hold = source_p->info;
before = strtok (hold, "^");
after  = strtok (NULL, "^");

and it still changes the contents of source_p->info

 

[xwb]

You didn't say that you didn't want the original value changed.

char* hold = malloc (strlen (source_p->info) + 1);
strcpy (hold, source_p->info);
before = strtok (hold, "^");
after  = strtok (NULL, "^");

 

[macd68]

xwb is sharp and I was going to let him ride, but...

BUGS
       Avoid using these functions.  If you do use them, note that:

              These functions modify their first argument.

              These functions cannot be used on constant strings.

              The identity of the delimiting character is lost.

              The strtok() function uses a static buffer while parsing, so it's not thread safe. Use strtok_r() if this matters to you.

There are better ways to deal with this but they'll not come cleanly from string.h and libc imho.

 

[tomchesley]

Thanks that did the trick

 

[tomchesley]

Well I thought it did the trick.
but if the string doesnt have a ^ it crashs

 

[trollacious]

Then you're going to have to check to see if before is NULL before proceeding.

Lee

 

[tomchesley]

DOH, didnt think of that thanks, but i checked both before and after for NULL
Now im set