I'm trying to do file compression/decompression in C and I need to handle one bit at a time.
I currently try to do:
unsigned char byte = fgetc(fptr);
and later
byte >>= 1;
but the problem is that I have to use the first bit of the byte and then treat the next 8 bits as one byte. The byte usage keeps shifting over in this way. It's probably quite clear that I'm a bit lost.
I am trying to get the code to read from the txt file one bite at a time and then write this bite into the binary file but i cant seem to get it working.
FILE *fpcust, *fpcustbin; //<<<<<-----point to both sales and customers text files, and the new .bin files for both
char buffer;
int ch;
int ch1;
fpcust = fopen("c:customers.txt", "r"); //<<<<-----pointing to the file
fpcustbin = fopen("c:customers.bin", "wb"); //<<<<<-----pointing to the new binary file, opening in writing binary
[Code]...
I am trying to read enormous binary files (10-100GB) and parse their contents a bit at a time. As part of the process I need to get the size of the file in bytes. The simple solution
Code: fseek(file,0,SEEK_END);
size=ftell(file);
fails because the file size overflows the long int type returned by ftell. I need a long long int.
Is there a reasonably efficient way to do this? The good news is that it only needs to be done once. I suppose I could read it one character at a time until I hit the end and keep count, but that just seems inelegant...
I'm trying to read in one value at a time from a file with this function, but its giving me back junk.
javascript:tx(
void ReadValue (istream &inF, int & num, bool & success) {
inF.clear();
inF.seekg(0L, ios::beg);
inF >> num;
cout << num;
[Code] .....
I have a file called example.txt . In that file, the int 123456 is stored. How can I read one independent number from that int? Lets say, I have an int variable called "Weight." How do I set weight equal to the number 1 from the int 123456 in the file?
View 4 Replies View RelatedThe objective: Open and read a CSV file one line at a time using SQL commands.
The problem: I am getting an error that I have a feeling may not point to the "real" problem.
Where I may have syntax or other errors in code.
stInputConn = "Provider=Microsoft.jet.OLEDB.4.0;Data Source=V:\IT\RE\Exports\;Extended Properties="text;HDR=YES;Format=Delimited(,)"";
OleDbConnection cn = new OleDbConnection(stInputConn);
stInputFileName = ConfigurationManager.AppSettings.Get("InputFile");
// the input file name is CSV_DataExport.CSV
[Code] .....
The last line (ExecuteReader) is where I get the OleDb Exception.
When reading a binary .img why is it when you read it by slurping in the file, then save it to a string and cout, you don't see the binary but random garbage?
View 11 Replies View RelatedI use the following function to read doubles from a binary file:
Code:
int64_t read_current(FILE *input, double *current, uint64_t position, uint64_t length)
{
printf("asked for %" PRIu64" samples
",length);
printf("reading from %" PRIu64 " to %" PRIu64 "
",position,position+length);
union{
double d;
uint64_t i;
}
[code]...
As long as position+length doesn't exceed the end of the file, all is well. However, if it does, weird things start to happen. In particular, the apparent length of the file (that is, the value of "read" after the function has finished) becomes dependent on "length"). I know that "position" is never past the end of the file.
I have this file want to read it source code [URL] ....
View 10 Replies View RelatedTrying to write very simple code to read a 4 byte int from a file.
code:
int tester;
FILE *fp;
fp=fopen("/home/bdluser/skeleton.blx","rb");
fread(&tester,sizeof(int),1,fp);
printf("tested 1 byte read should be 1: %i",tester);
I have tried editing the binary file....it outputs similar large numbers
00000000000000000000000000000001 outputs 808464432
0x00000001 outputs 808482864
0x10000000 outputs 808548400
10000000000000000000000000000000 outputs 808464433
x01 x00 x00 x00 outputs 813183068
x00 x00 x00 x01 outputs 813183068 same....
etc.etc. It just keeps returning the same large integers. I thought they were memory addresses but its consistent output/input so I guess not.
I would like to read in binary files, then write them to another file.
I write a code, what works perfectly, if I would like to just copy the file to another. But I want to make it a little other.
If I open a file in hex-editor I also can see the ASCII values. But I would like get the ONLY the hex values to the other file.
For example:
d5 57 4f ad 30 33 0b 4e 49 a7 05 18 c4 90 66 d8 45 ac 39 3e 7d f1 a8 02 80
14 20 90 6e 20 12 38 0c 65 4a 28 d2 80 72 04 20 a9 4a 82 84 60 6a 0b 25
59 4c 30 c8 69 c0 ec fa 36 ed 3a da b1 9a 82 02 e0 bb 7e 41 87 02 f6 10 34
eb 95 93 63 01 6b 8d e1 d7 43 c3 df 92 5d 8a ed 57 61 4e 36 07 2a d7 56 2b
b5 0e 55 83 b4 76 8c b7 61 77 0e c9 76 0c 81 1b 01 63 0c 8b 73 57 d5 6d 4c
0c c2 0d 52 45 18
How could I make it?
I want to read a binary file using as line separator "ff77" in order to parse further each line one by one with some regex since the file is big. I have a small ruby code shown below, but I'm new in C++, and I don't know how to replicate in C++ what this ruby code does.
Code:
#!/usr/bin/env ruby
BEGIN{ $/="xffx77" } # Line separator = FF77
File.open(ARGV[0],"rb") # Open in binary mode
[Code].....
I run with debugger and appear this file referring the error to line 142 (in red):
Code:
/***
*xtoa.c - convert integers/longs to ASCII string
*
* The module has code to convert integers/longs to ASCII strings. See
*
*******************************************************************************/
#include <cruntime.h>
#include <stdlib.h>
#include <limits.h>
#include <tchar.h>
#include <internal.h>
#include <internal_securecrt.h>
#ifdef _UNICODE
#define xtox_s xtow_s
[Code] ...
In the calls stack window appears this
Code:
=>msvcr110d.dll!xtoa_s(unsigned long val, char * buf, unsigned int sizeInTChars, unsigned int radix, int is_neg) Line 142C
msvcr110d.dll!_itoa_s(int val, char * buf, unsigned int sizeInTChars, int radix) Line 176C
Get_Blocks.exe!main(int argc, char * * argv) Line 224C++
Get_Blocks.exe!__tmainCRTStartup() Line 536C
Get_Blocks.exe!mainCRTStartup() Line 377C
kernel32.dll!7695336a()Unknown
[Frames below may be incorrect and/or missing, no symbols loaded for kernel32.dll]
ntdll.dll!76f19f72()Unknown
ntdll.dll!76f19f45()Unknown
It seems could be becuase to _itoa_s(), I'm using like this:
Code:
_itoa_s(CONVDEC(i), num, 10, 10);
sub += num;
I have a binary tree, and I want to store all information its leaves stores into a binary file and then read it.
What I tried:
A function that reads the tree, and whenever it finds a leaf, it writes in the binary file:
Code:
[...]
if(tree->right == NULL && tree->left == NULL){
fwrite(tree, sizeof(tree), 1, output);
}
[...] a
And in the main function:
Code:
[...]
for(i=0;i<5;i++){
fread(tree, sizeof(tree), 1, output);
printf("This is the leaf number %d", tree->num);
}
[...]
I'm trying to read 5 nodes just to see if its working but it isn't. The output shows the first node of the tree everytime.
So as a learning exercise, I am trying to read and write a binary tree to a file. After googling around, I decided to use a preorder traversal (including null nodes) to write the binary tree to the file. I got stuck trying to read a tree from a file. I can't figure out how to create an unknown number of nodes when they are needed. I could use an array, but that just seems bulky - plus it could run out of space. Is that what I have to do? I've heard of vectors before, but not very much.
View 5 Replies View Relatedif i have 2 variables for which values are given by the user,then,does the information get stored into the file in the name of the variable,or just like packs of information.....if the former is true,how to extract the information of a particular variable alone from the whole file?
View 4 Replies View RelatedI'm reading a binary file and I want to read all of the letters, but I have noticed that it doesn't read all of the letters and I think it is because of appears as data.
View 11 Replies View RelatedObjective of this program is to read binary data from a file and print it.
Code:
#include <stdio.h>
void readFile(void);
int main(){
readFile();
return 0;
[Code] .....
But When I Run This Code First It Print "Error." Then Rest Of The File.Say In My File I Have "I AM HUMAN", It Prints "Error. HUMAN"!!
I Cant Figure Out Whats Wrong In The readFile() Function.It seems right to me.
I would like to write a complete structure array to a file and read it back, recovering all the data. I have tried the following:
Code:
#include <stdio.h>
#include <string.h>
#define NUM 256
const char *fname="binary.bin";
typedef struct foo_s {
int intA;
int intB;
char string[20];
[Code]...
//---------------------------------------------------- but the mac field is reading back some random value repeatedly. Why is that? And how do I fix this?
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");
[Code] .....
My table:
Code:
Database name: test & Table name : Profilemaster
+-----+--------+
| PID | PNAME |
+-----+--------+
| 1 | APPLE1 |
| 2 | APPLE2 |
| 3 | APPLE3 |
| 4 | APPLE4 |
| 5 | APPLE5 |
| 6 | APPLE6 |
| 7 | APPLE7 |
| 8 | APPLE8 |
| 9 | APPLE9 |
| 10| APPLE10 |
+-----+--------+
I like to read the table and get the all PNAME into the combo box.
Using the below code i can read the table, but while loop takes 2 seconds to read 10 records in the Profilemaster table.
How can i reduce the reading time?
My Code is
void MainScreen::OnreadProfileName() {
CDatabase database;
CString SqlString;
CString sDsn;
CString pname;
sDsn.Format("Driver={MySQL ODBC 5.2 ANSI Driver};Server=localhost;Database=test;User=root;Password=client;Option=4;");
[Code] ....
Is any other way to reduce the query execution time?
I'm trying read a binary file. A binary files is continued with bytes(ascci characters). and the 1st position is the position 0(zero).
I'm trying read just some values from ICO file:
- the 3rd value is in 4th-1 position(number of icons); (See the table: [URL] .... )
- the with is the (numberoficons*16) + 4 (the 16 is the Entries structure size) position;
- the height is the (numberoficons*16) + 4 + 4 (the 16 is the Entries structure size) position.
now see the code:
int iconwidth;
int iconheight;
int iconcount;
FILE *iconfile = fopen(filename.c_str(), "rb");//open the file
fseek(iconfile,4-1,SEEK_SET); //put the file in position 6(the position starts from 0)
fread(&iconcount,sizeof(char),2,iconfile);//get 2 blocks with char size(2 bytes).. i'm getting the number of icons
[Code] ....
so what i'm doing wrong with block positions?
I have a structure stored in a binary file, now I want to read each string from it (or line), can I do that using fgets?
View 12 Replies View RelatedI am planning to use this mostly to copy binary files, but why won't this work with text???
input.txt
int main(int argc, char* argv[]) {
// open file
std::ifstream ifs;
ifs.open("./input.txt", std::ios::binary);
[Code] ....
output.txt
310^?z^@^@^@^@^@300367346^A^@
Will this method always work to copy a file?
#include <stdio.h>
#include <stdlib.h>
int main () {
FILE * pFile;
long lSize;
char * buffer;
size_t result;
pFile = fopen ( "myfile.bin" , "rb" );
[Code] .....
How to open binary for read and write? Why the buffer is char * buffer? i mean in binary u cant read chars . How can it be? how the data is represented? just like txt file? What the buffer will contain how to print this buffer???
I am writing an MFC app in Visual Studio 2012 that will open a JPG file as binary and read all the contents to a CString.
I am able to read it to a std::Vector, but that doesn't work much as i need to pass all the binary content as a MFC CString to another function.
More Update:
Let me explain the problem a little more deeper.
I am trying to call a JavaScript (JS) function in a HTML page and then want to pass the binary date. The C++ function that calls the JS is given below.
bool CallJavaScript(const CString strFunc,CComVariant* pVarResult);
The 1st argument is the JS Function Name and 2nd is the one to pass the Binary Data. 1st argument works fine as i am able to call the JS fucntion called "LoadImage" without any problem. Problem is with 2nd argument that's supposed to take the Binary data of the JPG file.
If i try to pass a std::Vector or std::string then it will give me an error.
But it's happy if i pass CString. But then with CString there's a problem with NULL characters.
Actually my plan is to pass the binary of a JPG to a JS function and let it display the JPG in the HTML page.
Can i typecast a Vector or std::string to a CComVariant*?