how to find out if a string is full?

[Tiago]

Hi,

Is it possible to find out if a chars string is full or half full?

I want to use realloc after a malloc, but only if the chars string is almost full...

TY

[laserlight]

What exactly does it mean for a string to be full or half full?

EDIT:

I want to use realloc after a malloc, but only if the chars string is almost full...

Keep track of the number of characters in use (size) and the number of characters for which space is allocated (capacity). When the size is close enough to the capacity, increase the capacity.

[Tiago]

What exactly does it mean for a string to be full or half full?

The size of a string is static, unless we change it... what I mean by full is with all the spaces or almost all the spaces occupied by non '\0' chars ...

[KBriggs]

Count characters until \0 is reached, and compare the count to the size of the string?

[Tiago]

Count characters until \0 is reached, and compare the count to the size of the string?

I believe it will spend too much time... is there any other way to get, for example, the penultimate character of a string faster?

[laserlight]

I believe it will spend too much time... is there any other way to get, for example, the penultimate character of a string faster?

As I said: keep track of the size and capacity.

[KBriggs]

Well yes, you can reference it directly, but then you are ignoring the possibility that there is a \0 in the array somewhere before that character and that the one you are looking at is garbage.

Or just do like laserlight said and keep track of any changes you make to the string as you go.

[Tiago]

As I said: keep track of the size and capacity.

I had already thought of that, just wanted to see if there was an alternative... I'll do it that way...

thank you both...

[iMalc]

If you're not tracking the size already then there's a good chance that you're already in danger of a buffer overflow, or data truncation.
It may go from 40% full to 10% overflowing in a single concatenation. To make sure that doesn't happen, you have to check that the initial length plus the length to concatenate is less than the current size. If not, you need to grow first.
You can't just rely on checking the length after each concatenation.