Unclear pointer and array Post: 302884194

Sponsored Content

Top Forums Programming Unclear pointer and array Post 302884194 by Don Cragun on Saturday 18th of January 2014 09:12:53 AM

01-18-2014

Registered User

It wastes exactly the same amount of space your code wasted. My changes to your code just made changes to keep you from overwriting data following the space pointed to by text if your input string is longer than the space you allocated for your buffer.

Are you going to keep 100 millions of lines of data in memory at once, or are you going to process a line at a time? If you are processing a line at a time, wasting something less than 100 bytes is absolutely nothing to worry about.

If you're going to try to malloc() 100 million buffers for your output substrings, you need to reconsider lots of issues as you design code to deal with that much data. (Note that you're talking about 800,000,000 bytes just to hold the pointers to your buffers!) Obviously, you could allocate space for your output buffer in your substring() function based on the length of the string it is actually going to store into that buffer.

This User Gave Thanks to Don Cragun For This Post:

Don Cragun

View Public Profile for Don Cragun

Find all posts by Don Cragun

9 More Discussions You Might Find Interesting

1. Programming

pointer

void main() { int a={1,2,3,4,5,6,7,8,9,10}; int *p=a; int *q=&a; cout<<q-p+1<<endl; } The output is 10, how? if we give cout<<q it will print the address, value won't print.... if we give cout<<p it will print the address, value won't print.... p has the base addr; q...

2. UNIX for Dummies Questions & Answers

Storing pointer array in C

All .. I am having a pointer array . And trying to store the addess into that pointer array . please see below the problem i faced code: int cnt1; char *t_array; char *f_array; for(cnt1=0; cnt1<1000; cnt1++) { t_array =...

3. Programming

pass a pointer-to-pointer, or return a pointer?

If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it: (1) one is to pass a pointer-to-pointer parameter, like: int my_malloc(int size, char **pmem) { *pmem=(char *)malloc(size); if(*pmem==NULL)...

4. Programming

C pointer/array duality confusion

Hi all, Can anyone provide help with getting the right syntax regarding array/pointers in C in the following code? Can't locate a specific example which clarifies this... Say I declare a typedef to an array of pointers to some type... /** * An array of ptrs to sections */ typedef...

5. Programming

help with char pointer array in C

i have an array like #define NUM 8 .... new_socket_fd = accept(socket_fd, (struct sockaddr *) &cli_addr, &client_length); char *items = {"one", "two", "three", "four", "five", "six", "seven", "eight"}; char *item_name_length = {"3", "3", "5", "4", "4", "3", "5", "5"}; ...

6. Programming

structure pointer array as function parameters

if i create an array of pointers to a structure "struct node" as: struct node *r; and create "n" number of "linked lists" and assign it to the various struct pointers r using some function with a return type as structure pointer as: r=multiplty(.......) /*some parameters*/ is...

7. Shell Programming and Scripting

best practises for scripting + a few unclear points

Hi guys, Besides the points bellow, what would best practices for scripting be ? 1) set the PATH 2) unset the current environment (set -u ?) 3) (re)set the IFS to default value - space (IFS="" <- is this correct ?) 4) check the return code for each action inside the script (cd, rsync,...

8. Programming

Character pointer to Character array

how to copy content of character pointer to character array in c programming.. char *num; char name=num;

9. Programming

Pointer for 2D array seems to be 3D in C

I am struggling with the pointer to 2D-array (cf: 2D array of pointers). Can anybody help me elaborate how the pointer x moves in the memory to access the individual of y, especially the high lighted lines? I have talked to one of the curators of the forum, but I am still not quite clear. Here...

LEARN ABOUT DEBIAN

graphics::primitive::insets

Graphics::Primitive::Insets(3pm)			User Contributed Perl Documentation			  Graphics::Primitive::Insets(3pm)

NAME

       Graphics::Primitive::Insets - Space between things

DESCRIPTION

       Graphics::Primitive::Insets represents the amount of space that surrounds something.  This object can be used to represent either padding
       or margins (in the CSS sense, one being inside the bounding box, the other being outside)

SYNOPSIS

	 use Graphics::Primitive::Insets;

	 my $insets = Graphics::Primitive::Insets->new({
	   top	   => 5,
	   bottom  => 5,
	   left    => 5,
	   right   => 5
	 });

METHODS

   Constructor
       new Creates a new Graphics::Primitive::Insets.

   Instance Methods
       as_array
	   Return these insets as an array in the form of top, right, bottom and left.

       bottom
	   Set/Get the inset from the bottom.

       equal_to
	   Determine if these Insets are equal to another.

       left
	   Set/Get the inset from the left.

       right
	   Set/Get the inset from the right.

       top Set/Get the inset from the top.

       zero
	   Sets all the insets (top, left, bottom, right) to 0.

AUTHOR

       Cory Watson, "<gphat@cpan.org>"

SEE ALSO

       perl(1)

COPYRIGHT &; LICENSE
       Copyright 2008-2010 by Cory G Watson.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.12.3							    2010-08-21					  Graphics::Primitive::Insets(3pm)