I know gdb has several means of exploring data, some of them quite convenient. However, I cannot combine them to get that I need/want. I would like to display some custom string based on the first n values of a big array starting at <PT_arr>, and the last m values of the same array at a distance (in this case) 4096. Looking something like this:
table beginning:
0x804cfe0 <PT_arr>: 0x00100300 0x00200300 0x00300300 0x00400300
table end:
0x804cfe0 <PT_arr+4064>: 0x00500300 0x00600300 0x00700300 0x00800300
printf let's me add custom text (like table beginning)
the examine x gives me that nice alignment, let's me read many elements and group them by byte, words, etc; and shows addresses at the left (which is ideal for my case).
x aligns the content of regions of memory in an easy to read manner with the size and unit parameters. (what I want)
display is constantly printing. (what I want).
The issue with display (manual), is that unlike examine x (manual) it doesn't have a size or unit parameter.
Is there a way to accomplish that?
Thanks.
If you have a statically allocated array, the Visual Studio debugger can easily display all of the array elements. However, if you have an array allocated dynamically and pointed to by a pointer, it will only display the first element of the array when you click the + to expand it. Is there an easy way to tell the debugger, show me this data as an array of type Foo and size X?
Yes, simple.
say you have
char *a = new char[10];
writing in the debugger:
a,10
would show you the content as if it were an array.
There are two methods to view data in an array m4x4:
float m4x4[16]={
1.f,0.f,0.f,0.f,
0.f,2.f,0.f,0.f,
0.f,0.f,3.f,0.f,
0.f,0.f,0.f,4.f
};
One way is with a Watch window (Debug/Windows/Watch). Add watch =
m4x4,16
This displays data in a list:
Another way is with a Memory window (Debug/Windows/Memory). Specify a memory start address =
m4x4
This displays data in a table, which is better for two and three dimensional matrices:
Right-click on the Memory window to determine how the binary data is visualized. Choices are limited to integers, floats and some text encodings.
In a watch window, add a comma after the name of the array, and the amount of items you want to be displayed.
a revisit:
let's assume you have a below pointer:
double ** a; // assume 5*10
then you can write below in Visual Studio debug watch:
(double(*)[10]) a[0],5
which will cast it into an array like below, and you can view all contents in one go.
double[5][10] a;
For,
int **a; //row x col
add this to watch
(int(**)[col])a,row
Yet another way to do this is specified here in MSDN.
In short, you can display a character array as several types of string. If you've got an array declared as:
char *a = new char[10];
You could print it as a unicode string in the watch window with the following:
a,su
See the tables on the MSDN page for all of the different conversions possible since there are quite a few. Many different string variants, variants to print individual items in the array, etc.
You can find a list of many things you can do with variables in the watch window in this gem in the docs:
https://msdn.microsoft.com/en-us/library/75w45ekt.aspx
For a variable a, there are the things already mentioned in other answers like
a,10
a,su
but there's a whole lot of other specifiers for format and size, like:
a,en (shows an enum value by name instead of the number)
a,mb (to show 1 line of 'memory' view right there in the watch window)
For MFC arrays (CArray, CStringArray, ...)
following the next link in its Tip #4
http://www.codeproject.com/Articles/469416/10-More-Visual-Studio-Debugging-Tips-for-Native-De
For example for "CArray pArray", add in the Watch windows
pArray.m_pData,5
to see the first 5 elements .
If pArray is a two dimensional CArray you can look at any of the elements of the second dimension using the next syntax:
pArray.m_pData[x].m_pData,y
I haven't found a way to use this with a multidimensional array. But you can at least (if you know the index of your desired entry) add a watch to a specific value. Simply use the index-operator.
For an Array named current, which has an Array named Attribs inside, which has an Array named Attrib inside, it should look like this if you like to have to position 26:
((*((*current).Attribs)).Attrib)[26]
You can also use an offset
((*((*current).Attribs)).Attrib)+25
will show ne "next" 25 elements.
(I'm using VS2008, this shows only 25 elements maximum).
I have a list of adjectives (found here), that I would like to be the basis for a "random_adjective(category)" method.
I'm really just taking a stab at this, as my first real attempt at a useful program.
Step 1: Open file, remove formatting. No problem.
list=File.read('adjectivelist')
list.gsub(/\n/, " ")
The next step is to break the string up by category..
list.split(" ")
Now I have an array of every word in the file. Neat. The ones with a tilde before them represent the category names.
Now I would like to break up this LARGE array into several smaller ones, based on category.
I need help with the syntax here, although the pseudocode for this would be something like
Scan the array for an element which begins with a tilde.
Now create a new array based on the name of that element sans the tilde, and ALSO place this "category name" into the "categories" array. Now pull all the elements from the main array, and pop them into the sub-array, until you meet another tilde. Then repeat the process until there are no more elements in the array.
Finally I would pull a random word from the category named in the parameter. If there was no category name matching the parameter, it would return false and exit (this is simply in case I want to add more categories later.)
Tips would be appreciated
You may want to go back and split first time around like this:
categories = list.split(" ~")
Then each list item will start with the category name. This will save you having to go back through your data structure as you suggest. Consider that a tip: sometimes it's better to re-think the start of a coding problem than to head inexorably forwards
The structure you are reaching towards is probably a Hash, where the keys are category names, and the values are arrays of all the matching adjectives. It might look like this:
{
'category' => [ 'word1', 'word2', 'word3' ]
}
So you might do this:
words_in_category = Hash.new
categories.each do |category_string|
cat_name, *words = category_string.split(" ")
words_in_category[cat_name] = words
end
Finally, to pick a random element from an array, Ruby provides a very useful method sample, so you can just do this
words_in_category[ chosen_category ].sample
. . . assuming chosen_category contains the string name of an actual category. I'll leave it to you to figure out how to put this all together and handle errors, bad input etc
Use slice_before:
categories = list.split(" ").slice_before(/~\w+/)
This will create an sub array for each word starting with ~, containing all words before the next matching word.
If this file format is your original and you have freedom to change it, then I recommend you save the data as yaml or json format and read it when needed. There are libraries to do this. That is all. No worry about the mess. Don't spend time reinventing the wheel.
I use libxmljs to parse some html.
I have a xpath query which has an "or" conjunction to retrieve basically the information of two queries
Example
doc.find("//div[contains(#class,'important') or contains(#class,'overdue')]")
this returns all the divs with either important or overdue...
Can I prefix or see within my result set which comes from which condition?
The result could be an array with an index for the match 0 for the first condition and 1 for the 2... Is this possible...
Or how can I find out which result comes from which query condition...
Thanks for any help...
P.S.: this is a simplified exampled of a sequence of elements which either have an important or an overdue item ... both, one or none of them... So I cannot go by looking for every second entry ... etc
This is the result I want to get...
message:{},
message:{
.....
important: "some immportant text",
overdue: "overdue date,
.....
}
There is no way to know which clause of an or XPath query caused a particular result to be included. It's simply not information that's kept around.
You'll either need to do entirely separate queries for important and overdue, or do one large query to get the entire result set (as you are now) and then further test each result's class to find out which one it is.
I'm trying to read files and create a hashmap of the contents, but I'm having trouble at the parsing step. An example of the text file is
put 3
returns 3
between
3
pargraphs 1
4
3
#foo 18
****** 2
The word becomes the key and the number is the value. Notice that the spacing is fairly erratic. The word isn't always a word (which doesn't get picked up by /\w+/) and the number associated with that word isn't always on the same line. This is why I'm calling it not well-formed. If there were one word and one number on one line, I could just split it, but unfortunately, this isn't the case. I'm trying to create a hashmap like this.
{"put"=>3, "#foo"=>18, "returns"=>3, "paragraphs"=>1, "******"=>2, "4"=>3, "between"=>3}
Coming from Java, it's fairly easy. Using Scanner I could just use scanner.next() for the next key and scanner.nextInt() for the number associated with it. I'm not quite sure how to do this in Ruby when it seems I have to use regular expressions for everything.
I'd recommend just using split, as in:
h = Hash[*s.split]
where s is your text (eg s = open('filename').read. Believe it or not, this will give you precisely what you're after.
EDIT: I realized you wanted the values as integers. You can add that as follows:
h.each{|k,v| h[k] = v.to_i}