Where the variable is stored has nothing to do with how it does pointer math. I can't see your code from here, but I'd venture they were all on the stack, with nothing in the heap. What type it's stored in does matter. Math on pointers is done in multiples of the base size, math on integers is just plain math.
So &a-&b is arithmetic on pointers themselves, and happens in multiples of the base size.
But if you convert them to integers first -- integers, not pointers to integers -- the compiler is no longer aware of any base size and does just plain arithmetic.
Try this:
This makes it more obvious what's going on.
When you do math on a pointer, it puts it in terms of it's base size. An integer pointer plus one, actually gets sizeof(int) added to it, in this case 4. For plain integers, it makes no adjustment.
Last edited by Corona688; 01-14-2011 at 06:44 PM..
Hi all,
Can anyone tell me a little about the datatype FILE, which represents stream. What does its structure look like, and in which header file is it defined and so on...
Ex :
FILE *fp ;
fp = fopen("filename", "w") ; (6 Replies)
I am writing some code to do analysis on the file system (HP-UX 11.11).
I am using stat(..) to get file information. My problem is that the file-size may exceed the data types defined in 'sys/stat.h' & 'sys/types.h' respectively.
Thus file-sizes in the Giga-byte range are not read correctly.... (2 Replies)
Hello,
I get this message : "Value too large to be stored in data type" when I try to open a 3Gb file.
Can someone helps me to resolve the problem.
Thank you very much (5 Replies)
I have seen it done at my job before, there is a command that will make a notepad and show the directorie path, subfolders, and size of the subfolders? But i dont want it to go lower than 2 levels for example:
folder_01 10 GB
subfolder_02 10 GB
subfolder_03 10 GB... (4 Replies)
I am using perl 5.8.0.
I need to check some values to see it they are floats. Our system does not have Data::Types so I can't use is_float. Is there something else that I can use? The only thing in Data is Dump.pm. I am not allowed to download anything to our system so I have to use what I have.... (3 Replies)
Dear All,
How internally memory allocated when we declare the float data type.
how many bytes allocated for decimal and how many bytes for fraction.
kindly help me in this regards. (2 Replies)
I'm not a unix guy so excuses my ignorance... I'm the database ETL guy.
I'm trying to be proactive and devise a plan B for a ETL process where I expect a file 10X larger than what I process daily for a recast job. The ETL may handle it but I just don't know.
This file may need to be split... (3 Replies)
Hi everybody,
I`m very new with PHP and Databases and I having the follow issue with prices data..
The original information is in CSV files.
The prices have formatted with commas and dots as follow:
12,300.99 -->(thousands separated by commas)
3,500.25 -->(thousands separated... (10 Replies)
This is from a program I wrote over in 1998 that I am trying to compile on a linux machine:
void write_line (FILE *fp, int rec_no, line_rec *arec)
{
fpos_t woffset;
woffset = (rec_no - 1) * sizeof(line_rec);
fsetpos(fp,&woffset);
fwrite(arec,sizeof(line_rec),1,fp);
}On the line... (2 Replies)
Discussion started by: wbport
2 Replies
LEARN ABOUT DEBIAN
xgsch2pcb
xgsch2pcb(1)xgsch2pcb(1)NAME
xgsch2pcb - gEDA/gaf gschem -> PCB workflow GUI
SYNOPSIS
xgsch2pcb [project]
DESCRIPTION
When designing a printed circuit board (PCB) it's often desirable to create a 'schematic' which shows the components to be used and their
connectivity in an abstract fashion. The connectivity information is then used to help when designing the actual circuit board.
gsch2pcb is a command-line tool, part of the gEDA suite, which is used to generate and update a PCB layout. It works with schematics cre-
ated by gschem, part of the gEDA suite, and layouts created by pcb, a PCB layout system commonly used with gEDA.
xgsch2pcb provides an intuitive, user-friendly graphical interface to gsch2pcb.
The main window is divided into three main areas:
o The toolbar at the top offers the usual options to quit the program and to load and save project files.
o The left hand 'Schematic' frame shows a list of schematic pages that the PCB layout will be based on. The 'Edit schematic' and 'Edit
attributes' buttons respectively launch gschem and gattrib to edit the selected schematic page.
o The right hand 'Layout' pane shows the name of the PCB layout file associated with the project. The 'Edit layout' button launches pcb to
edit a file, and will offer to update your PCB layout if necessary. The 'Update layout' button forces an update of the PCB layout even
if one isn't strictly necessary.
The update process will carry out the following actions to modify your layout, after launching pcb if isn't already running:
1. Remove any elements from the layout that are not in the schematic.
2. Find any elements that are in the schematic but not in the layout, and add them to the layout (in the top left corner). N.b. that it's
probably a good idea to leave this corner of your layout clear until the layout is more or less finalised, to avoid new elements inter-
fering with elements which have already been placed and routed.
3. Clear your rats and load a new rats nest.
4. Update the component pin names to match the pin names on the schematic symbol.
Note that the update process won't modify your PCB file on disk, and will take into account any changes you have made since you last saved.
02 January 2010 xgsch2pcb(1)