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Comments:
<0> when you do a free() what really happen?, what happen if i do free(p+10); (i did p=malloc 20 before);
<1> usually something bad.
<0> doenst free the the las 10 bytes?
<1> no!
<0> then how it know how many bytes must free?
<0> got a table?
<1> it knows to free as much as was allocated. you cannot free part of an allocation.
<0> ok
<0> my code is geting dirty
<0> I read a file to fille a structure, the structure got a pointer, . so i m using my structure pointing to the bytes readed from the file.
<0> with that i just do 1 malloc.
<2> man this looks crappy http://www.rafb.net/paste/results/4lbjWm90.html
<0> int myint = (u_short)-1;
<2> HellMind thats just a place i stuff a number to test
<1> any particular reason you are avoiding sprintf?
<3> are pointers only used for arrays, dynamic memory allocation and p***ing by reference?
<1> the code ***umes that the letters are always adjacent, which isn't universally true.
<1> [aG]Sociopat: are int's only used to hold int's? why does it do so little!
<2> twkm well its all i can think of and i have no idea what EwIck was refering to
<0> :P
<0> c got any default hash function?
<1> nope.
<0> look mine http://www.rafb.net/paste/results/AAuvXJ26.html
<2> twkm so is there a macro for conversion incase there not adjacent?
<1> winkey: nope. most people make an array.
<3> why cant the memory allocation functions return a value instead of a memory address?
<1> they do return a value. a pointer value.
<3> why?
<1> why not?
<3> because if you wanna free or to expand you just do &varname instead of varname itself
<1> so?
<3> so its less confusing
<1> wrong.
<3> there is virtually no use for pointers
<3> at all
<3> I cant find anything i can do with pointers that I cant do without
<1> when i write code i *know* that foo(x) cannot possibly change x.
<1> i know that bar(&x) probably will.
<3> twkm : thats detached from anything I claimed or asked
<1> *shrug*
<1> c was designed in the days when type were mostly unknown, but were becoming of more importance.
<3> so?
<1> so it had a small number of types, each of which has specific applications.
<3> give me an example
<3> of something I can do with pointers
<3> and cant do without
<1> the standard increased the number of types.
<1> i already did. if f() didn't take a pointer to int it would not be possible to change i.
<3> thats it?
<3> why calling it pointer?
<1> because it sounds silly to call it a floop.
<3> ok
<3> then there is only one real use
<1> the value points at something else, hence a pointer.
<3> whats all the big noise about pointers then?
<1> isn't that sufficient?
<3> no
<1> oh well.
<3> iv'e heard people claiming
<3> pointers are used to create dynamic data structures
<3> and stuff
<3> but they arent vital for it
<1> they tend to be critical to it.
<3> nop
<2> [aG]Sociopat heres a use for you, does it take more resources to p*** to a function an array like int myarray[65535]; or would it take less with p***ing a pointer?
<3> they dont
<1> what if you don't know how long a string might be? you cannot use an array. you must use allocated storage, which depends on the notion of a pointer to the otherwise anonymous location of the storage.
<1> winkey: since array's are p***ed by value, and the value of an array is a pointer to the first element, that isn't likely to be a useful question.
<3> that depends on the notion of an address not of a pointer
<3> and you can get to the address with &address
<1> no, you think it is called address.
<2> twkm good point
<1> c calls it a pointer value.
<2> think first i guess
<3> lk
<1> you'll be happy to know that the unary & operator is also called the address of operator.
<2> twkm a structure then ;-)
<3> what about linked lists?
<1> pointers tend to be useful there too, though if the upper limit on the number of nodes is known and small enough you need not use pointers.
<1> most likely anywhere you want to say "address" you really mean "pointer value".
<2> twkm wouldn't that take up alot of space if your note using all the "nodes"?
<1> if you feel you mean address then you aren't thinking in c yet.
<3> why would i wanna save an address (in a pointer)?
<3> I can always do &bla to get the address...
<1> winkey: sure, which is why the upper limit would have to be known and "small enough".
<1> [aG]Sociopat: what if you cannot?
<3> when cant I?
<1> malloc's return value cannot be &'d.
<3> why not?
<1> if i p*** a pointer value to you, you no longer know the name of the thing.
<2> what about the math? http://www.rafb.net/paste/results/sGKU8Y98.html
<3> so thats the reason it returns the location?
<3> because it cant reference the value?
<3> in any other way?
<1> [aG]Sociopat: because how do you use & with the returned value? &p would be the address of the thing named p, not the value it holds.
<3> I didnt get your last sentence
<3> rephrase
<3> twkm?
<2> [aG]Sociopat remeber that for looped i pasted
<2> for (*dst++ = *src++);
<2> thats basicly strcpy() write up one without pointers then paste it here http://www.rafb.net/paste/ then paste us the url
<1> sorry, i've some family things to do. if you are still wondering when i get back i'll take it up again.
<3> let me do some thinking
<3> if the allocation function returns a value, what do I do with it?
<3> I cant put it anywhere
<3> because what I got is the value not the allocated memory
<3> and the allocated place is lost actually
<2> it returns void *
<3> I get it
<3> but im too stupid to soak it
<3> int x is a variable, that is a cell in memory, &x is the address (the pointer value)
<2> char *mystring = NULL; if (!(mystring = malloc(50)) {exit(EXIT_FAILURE);}
<3> and x is the value in that cell
<3> its all about referencing
<3> is it possible returning the composition of address and reference of a variable?
<2> you program in java?
<3> im leanring
<3> learning
<2> or some other similar lang?
<2> address and reference?
<3> yes
<3> int x
<3> &x is address x is value
<2> int x = 4;
<3> is it possible returning x
<2> int *y = &x;
<2> y is a pointer
<2> the pointer points at x
<2> because we told it to here int *y = &x;
<2> char test[] = "hi there"; char *x = test char *y = x + 3; printf ("%s\n", x); printf("%s\n", y);
<2> what does the first printf print?
<2> what does the second one print?
<3> it prints t
<3> dosent it?
<2> no
<2> the firts one prints hi there
<3> oho
<2> the second one prints there
<2> %s is a string
<3> but x points to test
<3> as a whole
<3> it prints hi there completley it dosent stop before there
<3> it prints hi there there
<2> x points to "hi there"
<2> so does test
<2> in a way thats nox exactly correct but close
<2> string literals are given a place in memory
<2> char *y = x + 3; and char *y = x[3]; have the same result
<2> erm no
<2> sorry i am wrong
<3> x[3] is a value tho
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