I've been unable to parse the executable with the build of the following code:
#include <iostream>
#include <fstream>
#include <string.h>
#include <windows.h>
using namespace std;
int main(int argc,char** argv)
{
if(argc==3)
{
if(strcmp(argv[1],"-i")==0)
{
string DueEXE, DueVER;
DueEXE = DueVER = "";
DueEXE += argv[2];
cout << endl << DueEXE;
DueVER += "\"" + DueEXE + "\" -ver > \"C:\\\\DueVER\"";
cout << endl << DueVER << endl << endl;
system(DueVER.c_str());
}
}
return 0;
}
Prerequisites: 1. DueEXE holds the file location to an *.exe that prints (in console) its version when used with -ver or --ver.
2. I use Windows XP SP3.
3. I use Code::Blocks with MinGW32, if that matters.
Problem encountered:When I execute my build using cmd as follows-1. build.exe -i "D:\OA 2\Due.exe" 2. build.exe -i "D:/OA 2/Due.exe", the result is something like-
D:/OA 2/Due.exe
D:/OA 2/Due.exe -ver > "C:\DueVER"
'D:/OA' is not recognized as an internal or external command,
operable program or batch file.
I know that I have to parse the 3rd argument with quotes.
Additionally, the result should be like-
"D:/OA 2/Due.exe"
"D:/OA 2/Due.exe" -ver > "C:\DueVER"
The entire Due.exe file location must be covered with quotes, but that doesn't happen.What's going wrong in the code?
Oh!
I forgot to call the system() function with the variable covered in quotes.
Replacing system(DueVER.c_str()) with system(("\""+DueVER+"\"").c_str()) did my work.
Related
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <cstdlib>
using namespace std;
int main() {
string line;
cout << "HW\n";
getline(cin,line);
cout << "Your line is - " << line << "\n";
system("pause");
return 0;
}
I want to do gui to factorio headless server by myself so i need to exec few bash scripts. I think i need function system() to that ?
I think I got problem with lib path. Please don't blame to wrong installed vcpkg. Paths is :
/opt/factorio/bin/x64/vcpkg/installed
/usr/include/c++/9/x86_64-redhat-linux
/usr/include/linux
/usr/include/c++/9/tr1
Command system() not found says Visual Studio.
system("pause"); is meant to be used only on Windows. It runs the Windows command-line "pause" program and waits for that to terminate before it continues execution of your program. That's why it's a bad practice to use it in your code, no matter if you are running your code on Windows or Linux.
Here is a better way you can achieve the same result:
#include <iostream>
using namespace std;
int main() {
do {
cout << '\n' << "Press the Enter key to continue.";
} while (cin.get() != '\n');
return 0;
}
instead of:
#include <iostream>
using namespace std;
int main() {
system("pause");
return 0;
}
I have this short program:
#include <cstdlib>
#include <iostream>
#include <fstream>
#include <string>
int main (int argc, char * argv[]) {
std::string homedir = std::getenv("HOME");
std::string filename = argc > 1 ? argv[1] : (homedir + "/" + "file");
std::cout << homedir << std::endl;
std::cout << filename << std::endl;
std::fstream file;
file.open(filename, std::ios::out);
file << "Yo yo waddup" << std::endl;
file.close();
return 0;
}
When I supply no arguments, it opens a file in the users home directory. That of course makes sense. But when I run it from a different directory like this:
$ ./folder/hometest examplefile
The program creates "examplefile" in my current directory instead of the directory where the program is.
Why exactly is this happening?
Why exactly is this happening?
The program is behaving just as expected.
The file is opened relative to the current work directory, not where the executable is located.
If it didn't work that way,
All your programs will have to work with absolute paths, or
The location of the program will be flooded with files. First, that might not be possible because of permissions issue. Second, in a multi-user system, users will end up trying to create the same file names/directories.
Neither of the above is desirable.
I am trying to use Gnuplot on Windows with gnuplot_i.hpp. When I type "gnuplot" into cmd everthing works, so the PATH variable should be set correctly. This is my code:
#include <iostream>
#include "gnuplot_i.hpp"
using std::cout;
using std::endl;
int main(int argc, char* argv[]) {
try {
Gnuplot g1("lines");
} catch (GnuplotException ge) {
cout << ge.what() << endl;
}
return 0;
}
The output is Can't find gnuplot neither in PATH nor in "C:/program files/gnuplot/bin" .
When I add the line
Gnuplot::set_GNUPlotPath("C:/gnuplot/bin/");
it just changes to Can't find gnuplot neither in PATH nor in "".
What am I doing wrong here?
Found the answer myself: For some reason gnuplot_i.hpp expects your exe to be called pgnuplot.exe instead of gnuplot.exe ... Now everything works.
I'm trying to read a text file but nothing is coming out. I feel like maybe It's not linking correctly in my Visual Studio Resources folder but if I double click it - it opens fine in visual studio and it doesn't run into any problems if I test to see if it opens or if it is good. The program compiles fine right now but there's not output. Nothing prints to my command prompt. Any suggestions?
Code
#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;
int main()
{
char str[100];
ifstream test;
test.open("test.txt");
while(test.getline(str, 100, '#'))
{
cout << str << endl;
}
test.close();
return 0;
}
Text File
This is a test Textfile#Read more lines here#and here
You try to open file by name without path, this means the file shall be in current working directory of your program.
The problem is with current directory when you run your program from VS IDE. VS by default sets current working directory for runnning program to project directory $(ProjectDir). But your test file resides in resources directory. So open() function could not find it and getline() immediately fails.
Solution is simple - copy your test file to project directory. Or copy it to target directory (where your program .exe file is created, typically $(ProjectDir)\Debug or $(ProjectDir)\Release) and change working directory setting in VS IDE: Project->Properties->Debugging->Working Directory, set to $(TargetDir). In this case it will work both from IDE and command line/Windows Explorer.
Another possible solution - set correct path to file in your open() call. For testing/education purposes you could hardcode it, but actually this is not good style of software development.
Not sure if this will help but I wanted to simply open a text file for output and then read it back in. Visual Studio (2012) seems to make this difficult. My solution is demonstrated below:
#include <iostream>
#include <fstream>
using namespace std;
string getFilePath(const string& fileName) {
string path = __FILE__; //gets source code path, include file name
path = path.substr(0, 1 + path.find_last_of('\\')); //removes file name
path += fileName; //adds input file to path
path = "\\" + path;
return path;
}
void writeFile(const string& path) {
ofstream os{ path };
if (!os) cout << "file create error" << endl;
for (int i = 0; i < 15; ++i) {
os << i << endl;
}
os.close();
}
void readFile(const string& path) {
ifstream is{ path };
if (!is) cout << "file open error" << endl;
int val = -1;
while (is >> val) {
cout << val << endl;
}
is.close();
}
int main(int argc, char* argv[]) {
string path = getFilePath("file.txt");
cout << "Writing file..." << endl;
writeFile(path);
cout << "Reading file..." << endl;
readFile(path);
return 0;
}
I've got a pretty basic console program here, to determine if a folder or file exists or not using stat:
#include <iostream>
#include <sys/stat.h>
using namespace std;
int main() {
char path[] = "myfolder/";
struct stat status;
if(stat(path,&status)==0) { cout << "Folder found." << endl; }
else { cout << "Can't find folder." << endl; } //Doesn't exist
cin.get();
return 0;
}
I have also tried the access version:
#include <iostream>
#include <io.h>
using namespace std;
int main() {
char path[] = "myfolder/";
if(access(path,0)==0) { cout << "Folder found." << endl; }
else { cout << "Can't find folder." << endl; } //Doesn't exist
cin.get();
return 0;
}
Neither of them find my folder (which is right there in the same directory as the program). These worked on my last compiler (the default one with DevCpp). I switched to CodeBlocks and am compiling with Gnu GCC now, if that helps. I'm sure it's a quick fix - can someone help out?
(Obviously I'm a noob at this so if you need any other information I've left out please let me know).
UPDATE
The problem was with the base directory. The updated, working program is as follows:
#include <iostream>
#include <sys/stat.h>
using namespace std;
int main() {
cout << "Current directory: " << system("cd") << endl;
char path[] = "./bin/Release/myfolder";
struct stat status;
if(stat(path,&status)==0) { cout << "Directory found." << endl; }
else { cout << "Can't find directory." << endl; } //Doesn't exist
cin.get();
return 0;
}
ANOTHER UPDATE
Turns out that a trailing backslash on the path is big trouble.
Right before your stat call, insert the code:
system("pwd"); // for UNIXy systems
system("cd"); // for Windowsy systems
(or equivalent) to check your current directory. I think you'll find it's not what you think.
Alternatively, run the executable from the command line where you know what directory you're in. IDEs will frequently run your executable from a directory you may not expect.
Or, use the full path name so that it doesn't matter which directory you're in.
For what it's worth, your first code segment works perfectly (gcc under Ubuntu 10):
pax$ ls my*
ls: cannot access my*: No such file or directory
pax$ ./qq
Cannot find folder.
pax$ mkdir myfolder
pax$ ll -d my*
drwxr-xr-x 2 pax pax 4096 2010-12-14 09:33 myfolder/
pax$ ./qq
Folder found.
Are you sure that the current directory of your running program is what you expect it to be? Try changing path to an absolute pathname to see if that helps.
Check your PWD when you running your program. This problem is not caused by compiler. You DevCpp may set a working directory for your program automatically.
You can find out why stat() failed (which is a C function, not C++, by the way), by checking errno:
#include <cerrno>
...
if (stat(path,&status) != 0)
{
std::cout << "stat() failed:" << std::strerror(errno) << endl;
}