Writing assignment for my class, I understand the portions completely, and I understand the body of the code that is given here.

I need someone to write the entire program and make sure it works. Paying up to 500 Forum Gold for this. It's very basic. This is a second tier intro course to C.

It is due Wednesday 10/16 at 11:59 Pm (midnight)



It's basically reading strings from a FILE, and publishing them to an output file, without using scanf. And properly allocating space to do so.

Using pointer in/pointer outs/malloc/free ONLY.

Very basic.






I have the PDF link, if you're interested in this PM me for it. It's a very detailed assignment cover.

I have written most of it, this is the part I need written

Basically the program uses a pointer to read in a string of unknown length, I have to determine the length of the string that is read-in by using the function below, to allocate space and create a string (array) out of it so I can send it to an out file pointer.
Not allowed to use strlen function of course.



#define DEFLEN 1 /* 1 is good number for testing */
#define CHUNSZ 1 /* 1 is good number for testing */
/*
* This function safely reads a complete line of unknown length from the
* open file pointed to by fpin. It returns a line that is at most CHUNKSZ-1
* characters longer than the minimum needed to hold the line.
* It initially allocates an array of DEFLEN characters to hold the string,
* and if this space is inadequate to hold the string, it will iteratively
* create a new string that is CHUNKSZ larger, copy the old string to it
* release the old string, and then read in more characters from the file,
* and continue this until the entire line of arbitrary length can be returned.

iirc a string terminates with a null. so just keep reading until you hit null.

I'm so new to programming

So...

char *ln;
ln = getStrFromFile(fpin);

while ( ln != NULL)
{
...
}


char getStringFromFile(FILE *fpin)
{
char *array[256]

fgets(array, 256, fpin);
return array;
}


It's imperative that I use the function provided, it's more for learning and the professor wants to see it to give credit for it. Basically increasing a string by 1 and copying it until I have sufficient length.

Should be "char* getStringFromFile(FILE *fpin)"

I'd advise against char *array[256]. use char *array = (char*)malloc(256); instead



that's your basic way to grab the null terminator, without bursting out of the predefined length

getStringFromFile is a little weak though. fgets won't read the full buffer size if it hits a null character. You're better off feeding the pointer to it as an argument and using it to return the amount of characters read, which will implicitly give you the string length. Also you should consider zeroing the buffer before reading to it, better practice when it comes to random size strings.

This post was edited by flyinggoat on Oct 18 2013 02:41pm

What about using sizeof?

Way to necro.

sizeof won't work - it'll either return the size of the buffer array or the size of a pointer, neither of which is what you want.

Here's an example: http://ideone.com/gPfBJI

Oh someone else necro'd before me. But you can size of a pointer. I had to do it in a project before.



Here's part of it. I don't want to post the whole thing because the programs big. But this is the general idea. There are multiple ways to do this.

No? 18 Oct to 20 Dec, you necromancer.

sizeof of a pointer will yield size of the pointer, not size of the value under it. sizeof of an array will yield the size of the array. Neither of which are suitable to tell length of a string: it may be shorter than the full length of the buffer and it's not very likely to match size of a pointer. All in all, even if it is occasionally right, it's a case of a broken clock being right twice a day.

In your example you use a classic array size macro idiom, but it won't work if size of your array size doesn't match the length of a string, or if there is no array to begin with - that is when you're dealing with a pointer. And I have already posted an example displaying both these cases giving incorrect results: http://ideone.com/gPfBJI