C++ :: Open File For Writing Relative Path Given On Runtime
May 18, 2014
How it make it work for my project. Runtime means I am going to have to give the path at the command line?
Here is how I have to run it, so I can test it against the example inputs and outputs they give us to test our program. I am using putty. Already crated the folders inside my project folder, but don't know how to implement it on my source code.
Is there a way to change what a relative path is referencing after runtime has started?
My specific issue is that I have several existing 100,000+ LOC lua projects. I am building a new back-end in C/C++ for this by wrapping a Lua C library. The lua scripts use io.open("./path/relative/to/project/file") which translates to fopen(...) in C. The project file which this is relative to is opened by the user after the application has started.
I see two solutions, neither are particularly good:
1) Change every io.open() function in every project to be relative to a static location. I lose all flexibility if I do this.
2) Modify the Lua library to prepend a custom path to opened files. Modifying 3rd party libraries suck because you can't update the library without tracking patches.
3?) Ask cplusplus forum if there is a way to change the relative directory.
I have my application database in the AppDataRoaming folder. I'm trying to create a connection string for Telerik reporting, up until now I've had a connection string in a settings class that is put together like this:
The path is:
data source=C:UsersSynlightAppDataRoamingAppNamedataAppDB.sqlite
I'm using Visual C++ 6.0 and I'm trying to use fstream to open and read a file that is created only during runtime. This file is written by another function running on another thread, and my program will keep trying to "open" the file until it can be opened, i.e. after it's created, then read 3 numbers from it and execute the rest of its code.
The file test.txt has the content
Code: 1 3 4
My program that polls and opens the file is as follows:
Code: ifstream fin; std::string tfile, snum1, snum2, snum3; long int num2, num3; tfile.assign(argv[1]); printf("Begin prog %s ", tfile.c_str());
[code]....
I executed the program by
Code: test_prog.exe "C: est.txt"
and waited about 3 seconds before putting the test.txt file into C:
My output was
Code: Begin prog C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt fin is open snum1 = num2 = 0 num3 = 0 End of prog
The test.txt file disappears after I refresh the C: folder.
So the values for snum1, num2 and num3 are all wrong, as if the file was not read correctly.
If I put a while fin.good() loop after printf("fin is open "); for that entire block (until printing the values of num2 and num3), then I get
Code: Begin prog C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt Cannot open file C: est.txt fin is open End of prog
How can I correctly read a file that is only created during runtime?
I am trying to open a file and print the contents of the file to the terminal window. It works when I put the file right in the directory with the Solution but not if the file is out on my desktop and I use the full path. Here is the code:
#include <iostream> #include <fstream> #include <string> using namespace std; int OpenFile(){ fstream SampleFile;
I'm doing a project. And I want to give the user the ability to write methods just like you would regularly in c# during runtime and then use them during runtime. Is such thing even possible? If so how?!
For a while, I have been running a Windows 7 Visual Studio 2012 CPP project fine. However, today, all of a sudden, it has stopped being able to read any header files that are in relative directories. I cannot think what I have done to make this happen.
It seems to be an issue with Visual Studio as a whole, rather than my individual project, because I have created a new simple project and I am having the same problem. So, I have a CPP project at `C:/Projects/TestProject`. Then, I have a header file called `test_header.hpp`, which is located at `C:/Headers`. In `TestProject`'s project settings, I have added the directory `../../Headers` to `Additional Include Directories`. Then, my main functions is as follows:
Code: #include "test_header.hpp" int main() { return 0; }
Which gives me the error:
Code: Error1error C1083: Cannot open include file: 'test.hpp': No such file or directoryc:projects estprojectmain.cpp11TestProject
Is there some global Visual Studio setting that is responsible for setting up these relative directories? Just in case the relative directory was not correct, I also tried a load of others, such as `../Headers` and `../../../Headers`, but these gave the same errors.
I wanted to make my program read the file "input.txt". I did it successfully, but now I want to get the full path of the file "input.txt". Is there any way to do it?
I am trying to iterate through a file path to extract the file name. since the . separating the name from the extension is a unique character, i thought i would reverse iterate from the . to the first separating directories. however, when trying to reference the memory location of the position of the . in the string, i am getting an i-value error:
for (std::string::reverse_iterator iter = &(songPath.find('.')); iter != songPath.rend(); ++iter) { if (*iter == '') break; else songName.push_back(*iter); }
I've come to a point where I want to manipulate an image file at run time or with pre-determine sizes and have to be applied when the windows is moved or through in program options.
I know I can do the applying part. However I am a little unsure of how to tackle the image manipulation. I want to make it so that it is not os dependant. So I know I can not rely on any os functions. The only other thought that came to mind was to deal with the video card itself.
So the main question after all of that is said and done. How is c++ able to interact with the video card directly for images? Or if there are existing function I can use. How do they do that? If I can use existing function I would like to be able to manipulate it myself.
I need to open a text file game_scores.txt and i can not figure out a way to.
#include <iostream> #include <string> #include <fstream> using namespace std; int main() {
[Code] ....
the code is used to read the text and take the first 4 pieces of info but i do not know how to do it. i have already created the text file and moved it into the source. i am using visual studios 2012. In 2010 the text file would show a relative path, it doesn't in 2012
I need to append file path for some particular program. But the problem is when I append it like below, it gets error whether filepath seems to be C:/Users/My/Desktop/C++/1.txt
int i=1; stringstream str; str<<"C:/Users/My/Desktop/C++/"<<i<<".txt"; string filepath=str.str(); cout<<filepath; ifstream ipf(filepath); if(ipf) { do some thing...}
But if it was like this no error, program work as desired.
int i=1; stringstream str; str<<"C:/Users/My/Desktop/C++/"<<i<<".txt"; string filepath=str.str(); cout<<filepath; ifstream ipf("C:/Users/My/Desktop/C++/1.txt"); if(ipf) { do some thing...}
Suppose there are two cpp programs and we want the user to put the complete path of the first cpp file into second cpp file while it(second file) is running and compile and show the output there, so how can this be done?
Basically, this function purpose is to make a backup of source in folder every X minutes (depending on user's input).
The problem is the second call to open():
This call attempts to open the file for writing, and creates it if it is not already exist.
It also truncates it before writing to it - and that's my concern:
Let's say this is the second time this function runs, so copy is already exist. open() will then truncate it, and then one of the system calls in the while loop fails.
In this situation, I might be left with no backup file.
The problem also arises for when source is a read-only file:
If source is a read-only file, and copy is not already exist (meaning - it's the first backup attempt), then everything's fine, but, if source is a read-only file and copy is already exist, then I have to first remove copy altogather, and make a fresh copy of source.
Making a backup with new name for copy every time copy_file() runs, will solve this problem, and how can this be accomplished?
I should say that I'd really prefer that copy and source will have the same names when copy_file() returns...
How can I take in a path name like "C:myfolderfile.txt" where the user enters exactly that? I've tried putting the arg into a string, then looping through the string to find the '\', but by that time it is too late as c++ considers the '' as a escape character.
Is this even possible? I've googled it and everyone just says to make the user input the path with double \ or with a /.
Is there any way in sfml version 2 that I can get objects in a graphics window to retain there relative positions and sizes when the window is resized? I have tried looking in the documentation for version 2 but with no luck.
As an example suppose the window is 800x600 and there is a line running right across the window at 3/4 of the way down (i.e at y=450). If the window is then made larger say 1280x1024 how would I keep the line in the same relative position (i.e all the way across 1280 and 3/4 of the y setting down).
How to get relative memory address of members of Class or Structure ? I want to auto scan the members of Class/Struct, and show the address/value like the "watch window" in debug mode of popular C/C++ IDE software.
I have an application which is used for calibration for electrical components. Here I want to set a rootpath for this application. I did some research and I found out that I can get the rootpath of the application (that is where the exe is stored) But what I am really looking for is once I start the application the root path should be what I assign. For instance currently the root path is "C:UsersPublicDocumentsABC.ToolsProjects" but I would like the root path to be "E:New ABC" Is this possible? I wrote some code where I call the exe of the application and it opens the file in a folder that I specify :
Is it possible to create a program like Robocode, a game controlled at runtime by an external source file in visual c ++? For example create a checkers game where there would be an external source file, read at runtime, which would play automatically, with artificial intelligence. You can? If yes, how?
Compilation is success full ,but i am observing that some junk value is there in the path variable. After Reaching If statement cursor went to final return statement ...
