C++ :: Combine Multiple Vector Containing Binary Data To String?
Mar 16, 2012
Two questions:
1. I have some vector<unsigned char> containing binary data. I would like to combine them into one std::string. How is the correct way to accomplish this?
This is my best guess for sample code:
Code:
vector<unsigned char> data; //conatins some data
vector<unsigned char> data2; //contains more data
string temp(data.begin(), data.end());
temp.append(data2.begin(), data2.end());
Will this code work with binary data, or will it null terminate?
2. A similar problem.. I have some unsigned char* variables, and I want to combine them into one std::string. How can I accomplish this? will the member append() work here? or will it null terminate? Something like:
Code:
unsigned char* data; //conatins some data
unsigned char* data2; //contains more data
string temp(reinterpret_cast<const char*>(data));
temp.append(string(reinterpret_cast<const char*>(data2)));
Will the above sample code work without null termination?
When you have to write data on a file in binary mode multiple times (without closing the file), is the put pointer left where you ended writing the last time, or do you have to use tellp() or seekp() again and again to make sure you write at the right place?
I would have the same question about the get pointer, does he stay in place after you're done reading something (without closing the file, of course), or do you have to set it back at the right place with seekg() ??
I am writing a program where I need to read a byte of char data and convert it into a text string of binary data that represents the hex value...
i.e. The char byte is 0x42 so I need a string that has 01000010 in it. I've written the following subroutine....
------------- My Subroutine ---------------------------------------------------------------------- void charbytetostring(char input, char *output){ int i, remainder; char BASE=0x2; int DIGITS=8; char digitsArray[3] = "01";
[Code] ....
When I submitted the byte 0x42 to the subroutine, the subroutine returned to the output variable 01000010... Life is good.
The next byte that came in was 0x91. When I submit this to the subroutine I get garbage out.
I am using a debugger and stepped through the subroutine a line at a time. When I feed it 0x42 I get what I expect for all variables at all points in the execution.
When I submit 0x91 When the line remainder = input % BASE; gets executed the remainder variable gets set to 0xFFFF (I expected 1). Also, when the next line gets executed..
input = input / BASE; I get C9 where I expected to get 48.
My question is, are there data limits on what can be used with the mod (%) operator? Or am I doing something more fundamentally incorrect?
So I've been working on this for awhile and FINALLY got it to work. This is my code
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text;
[Code] ....
As you can see I will have the Name and total right next to eachother.. Problem is I dont want to make a million MySQLCommands for each ID.. Is there a Way I can list all data in each label?
For instance the Select from Text will show all the text from each different ID and the Select from STOCK-USED as total will show all the total for each ID
Instead of having to list them individually.
Even if I leave it to this
"Select text FROM `parts`";
It selects the 2nd ID in my database and displays its text.. Forgets about the first one completely ...
I have a cpp app that reads in a number of files and writes revised output. The app doesn't seem to be able to open a file with a ' in the file name, such as,
N,N'-dimethylethylenediamine.mol
This is the function that opens the file :
Code: // opens mol file, reads in rows to string vector and returns vector vector<string> get_mol_file(string& filePath) { vector<string> mol_file; string new_mol_line; // create an input stream and open the mol file ifstream read_mol_input; read_mol_input.open( filePath.c_str() );
[Code] ....
The path to the file is passed as a cpp string and the c version is used to open the file. Do I need to handle this as a special case? It is possible that there could be " as well, parenthesis, etc.
I'm trying to make a 2d shooter with SDL and I got as far as having multiple bullets but they act as one when a bullet goes off screen. I shoot 1st bullet, then I shoot 2nd bullet. 1st bullet goes off screen (deletes) and 2nd bullet disappears. I shoot 3rd bullet, 2nd bullet reappears where it disappeared and repeat.
class Bullet { public: static const int BULLET_WIDTH = 15; static const int BULLET_HEIGHT = 25; static const int BULLET_VEL = 5;
Bullet(); //xFire, yFire - position relative to player
[Code] ....
I'm guessing the problem is in the bullet_move function, but I just don't know what to do.
I have a vector that I would like to access and work with from multiple threads. I have created an example below to illustrate the functionality that I would like to accomplish.
The goals are to be (1) high speed, (2) thread safe, and (3) *if possible* continue to use vectors as my larger project uses vectors all over the place and as such I would like to maintain that.
However, if I need to switch from vectors to something else then I am open to that as well.
The following example below compiles but crashes rather quickly because it is not thread safe.
How I can fix the example below which I can then apply to my larger project?
Following is the program I wrote it basically takes 9 inputs and then save them into binary file. then print out the data stored in binary data and find inverse of it then print the inverse out. but its stuck in a loop somewhere.
Code: #include <stdio.h> int main() { int a[3][3],i,j; float determinant=0; int x; FILE *fp = fopen ("file.bin", "wb");
My program writes a vector to a file in binary. I want to erase the vector, then read the file to repopulate the vector then display.
Basically I want to erase the RAM memory and be able to use the file as memory. This is my current code but it is not reading the file correctly. I have checked the file to see that the writing part is working.
void read_from_file(vector<Info> &vector) {fstream file; file.open("info.dat", ios::binary | ios::in); if (file.fail()) { cout<<" FILE DOES NOT EXIST "; system("pause");
I have a buffer which has a virtual width of 1024 pixels with virtual height 768 pixels (actual width stored in GPU.GPU_screenxsize, height in GPU.GPU_screenysize (both uint_32)).
I currently use the following function to plot the pixels to the screen:
inline void GPU_defaultRenderer() //Default renderer { uint_32 pixel; int bufferx; //Buffer's x! int buffery; //Buffer's y! int bufferxstart; //Buffer's x start! int bufferystart; //Buffer's y start! int pspx;
[Code] ...
How to combine the pixels together (blend them into one goal pixel) to get a better view? (Currently it takes the bottom right pixel of the area that represents the goal pixel).
So (x1,y1,x2,y2)->(pspx,pspy) = (bufferystart,bufferxstart,buffery,bufferx)->(pspx,pspy). Atm this is (x2,y2)->(pspx,pspy)
Btw the pixel format is uint_32 RGBA (only RGB used atm). The psp_graphics_putpixel draws it onto the real VRAM. PSP_SCREEN_ROWS and PSP_SCREEN_COLUMNS represent the destination screen (the real screen)'s height and width in pixels.
update Tag_Master set flag='Inactive' where Tag_no=10;
update Tag_Master set flag='Assigned' where Tag_no=12;
I had these two queries, I just want both of these will fire on same event. Is any other way to write both queries in single query instead of writing two different queries ....
I have problem with string compare. I want to compare the string user input with a string in binary. And I don't know how to do it. Problem in function login();Here is the code: And you also can download file in attachment too..
I am making a multiple quiz program. So everything is working fine, except for the part where i'm trying to add a highscore for each user which is being stored in a binary file. I have added a sample of the program containing the error. This isn't the actual program, which is very long.
class user { //The collection of all info pertaining to the users char user_id[50]; public: int hscore1; user() { strcpy(user_id,"NULL"); hscore=0;
I wrote a program that reads a list from a file and stores it in a string type vector. Now, I want the user to input a word so that the program can search the vector to see if that word already exists. I have used every possible way of reading input from the console and storing it in order to compare with the vector but it never results in a match. When I print the input string and the vector string they are exactly the same thing (or at least print to the console as if they were). I've tried using getline; using cin direct to a string var; using cin to a char array and then casting to string using string str(arr); I even added a newline at the end just in case and STILL I cannot get a match.
vector <string> currentSet; //read a list in from a file and has 9 items in it cin.ignore(); string line; getline(cin, line); if(line == vector[0]){//if printed to console line is HEAT and vector[0] is HEAT cout<<"match"<<endl; }
