I'm trying to compile and run the app, which was created 4 years ago. It was developed for Windows in Embarcadero RAD Studio C++ builder. Now I try to compile and run it in Windows in VirtualBox using the latest version of RAD Studio. I have a system call to another app in my app:
system("dot.exe -Tjpg -o nfa.jpg NFA_graph.txt");
It keeps returning 1 and the file is not created. I also tried
system("Echo %CD% >> z:\log.txt");
and the file is not created. I also tried like this:
FILE *fpipe;
char *command = "Echo %CD% >> z:\log.txt";
char line[256];
if (0 == (fpipe = (FILE*)_popen(command, "r")))
{
perror("popen() failed.");
exit(1);
}
while (fread(line, sizeof line, 1, fpipe))
{
ShowMessage(line);
}
_pclose(fpipe);
And nothing I get. I wonder if the reason of such strange behaviour is that I'm running this all in VirtualBox?
You're not escaping your \ characters. You should use / in file paths, or \\ if you must. In addition, Windows 7 won't let you write to the root directory of a hard drive w/o administrator access.
To determine if a command environment is available, first do this:
if (!system(NULL)) {
// Can't make any system() calls
}
If your command environment is available, then you need to fully specify the path, making sure to escape the \'s like I mentioned above, and don't write anything to a drive's root directory. Also make note that opening files does not default create directories.
No, it's very unlikely. I see few issues with your code: you did not check errno if system() returns 1. It can help you to spot a real problem. Also, all backslashes must be Esc'ed.
I'm suggesting that dot.exe is not in PATH environment variable, that's the reason of the system() failure.
Related
Hello friendly people of stack overflow!
I am currently working on a project using an Arduino Uno. Because i create all my files and sketches using a c++ program, i want to eliminate the Arduino IDE from my workflow. For that i can very easily use avrdude (which the IDE uses anyway) and some windows console commands.
These are the commands that i am using:
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude" "-CC:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf" -v -patmega328p -carduino -PCOM4 -b115200 -D -Uflash:w:C:\Users\Jzargo\AppData\Local\Temp\arduino_build_766345/EPaper_TestDither.ino.hex:i
"EPaper_TestDither.ino" is the arduino Sketch i want to compile and upload. When using the console and manually inserting the above commands, everything works as expected.
And here comes the part I am struggeling with:
Because i also dont want the user to manually open the console and type in some gibberish code, i want to integrate this command into my c++ program using the system(); function:
system("\"C:\\Program Files(x86)\\Arduino\\hardware\\tools\\avr/bin/avrdude\" \" - CC:\\Program Files(x86)\\Arduino\\\hardware\\tools\\avr/etc/avrdude.conf\" -v -patmega328p -carduino -PCOM4 -b115200 -D -Uflash:w:C:\\Users\\Jzargo\\AppData\\Local\\Temp\\arduino_build_766345/EPaper_TestDither.ino.hex:i");
When executing this function, the command cannot be executed because "Der Befehl "C:\Program" ist entweder falsch geschrieben oder konnte nicht gefunden werden.", which roughly translates to "The Command "C:\Program" is not written correctly or cant be found".
I do not understand why the console accepts the command when manually inserting it, but not when using the system(); function.
I hope you can help me figure this out.
Edit: By using
subst H: "C:\Program Files(x86)\Arduino\hardware\tools\avr\bin" and
system("\"H:/avrdude \"-CC:/Program Files (x86)/Arduino/hardware/tools/avr/etc/avrdude.conf\"\" -v -patmega328p -carduino -PCOM4 -b115200 -D -Uflash:w:C:/Users/Jzargo/AppData/Local/Temp/arduino_build_833906/EPaper_TestDither.ino.hex:i");
I was able to upload my sketch. Note the changed Placement of \".
But for some reason, this does not work when using C:\Program Files(x86)\Arduino\hardware\tools\avr\bin instead of H:.
Kindest regards
J'zargo
The command looks messed up with respect to the parameters, although I don't see how exactly that triggers your specific error.
The beginning is OK. The path is properly quoted (double quotes, protected by backslashes from the C compiler). But why do you have slashes and backslashes mixed? In some online examples I saw that people use forward slashes in Windows paths (C:/whatever...) ; that seems to work and is easier than using double backslashes all the time (but it should not trigger your — or any — error).
So system("\"C:\\Program Files(x86)\\Arduino\\hardware\\tools\\avr/bin/avrdude\" ... should call the right executable. Why don't you try that on its own (without parameters) to see whether the error persists?
I suspect that \" - CC:\\Program Files(x86)\\ ... is not correct though. avrdude expects a parameter -C<path>, not - C<path> (note the badly placed spaces before and after the dash).
As an aside, it may not hurt to quote parameters that contain funny characters like colons which may have special meanings.
The general advice for this kind of trouble:
Work in and with paths that do not contain spaces, brackets, or other non-identifier characters. If you don't want to change the avrdude installation path you can use the DOS subst command to create a drive whose root is C:\Program Files(x86) or even C:\Program Files(x86)\Arduino\hardware\tools\avr\bin, e.g. subst H: "C:\Program Files(x86)\Arduino\hardware\tools\avr\bin". The command would then be H:/avrdude :-).
If confronted with a bug you don't understand, simplify the problem radically until a toy version works; then add complexity bit by bit until you encounter the error; that should make it easier to recognize what triggered it.
Edit: I'm not sure this example is valid because I used the msys2 development environment and ran the example in a bash shell; I'm not even sure cmd is called as the system shell by the syste call!
In order to check the system call semantics I wrote the following minimal example (which uses mixed slashes/backslashes as a test). The current directory has a sub directory called "some dir" containing a minimal program showargs which simply writes its command line parameters to stdout:
$ ls -l "some dir" && echo && cat cmdline.c && echo && gcc -o cmdline cmdline.c && ./cmdline.exe
total 56
-rwxr-xr-x 1 Peter None 56097 Apr 16 17:23 showargs.exe
#include <stdlib.h>
int main(int argc, char **argv)
{
system("\".\\some dir/showargs\" 1 2 3");
}
->.\some dir/showargs<-
->1<-
->2<-
->3<-
I recently decided to start teaching myself C++ and thought a simple encryption project would be a good place to start, since it covers most of the basics (cout, cin, opening files, etc). Is there a way to have the code open a terminal window similar to the one opened when I compile and run from sublime text?
I have tried this so far, but it hasn't changed anything.
string cmd = "gnome-terminal-x sh-c 'ls-l; exec bash'";
system(cmd.c_str());
Essentially, I would like to be able to run the program by clicking the .exe, and have the terminal where all of the input and output goes pop up.
You don't need to write any code, you just need to configure the shortcut to launch the program in a terminal. Here's a Gnome dialog that shows that option:
Problem seems to be gnome-terminal, or then just my failure to give it the right arguments. For example gnome-terminal -x sh -c 'ls -l ; exec bash' from command line in another terminal just opens an empty gnome-terminal and spits out a bunch of glib warnings to original terminal... (Note to readers: if you can give the right command that works for gnome-terminal, please let me know in comments or just edit this paragraph.)
However, using xterm works, for example xterm -e sh -c 'ls -l; exec bash', or a line for your code:
string cmd = "xterm -e sh -c 'ls -l; exec bash'";
As a side note, the command to open the default x terminal window of the DE is x-terminal-emulator, but it quite often has the practical problem of different terminals taking different arguments, so sadly you're probably better of using a specific terminal, like that xterm, and requiring that to be installed, or letting user to configure what terminal to use, with what arguments (though letting user to specify any command to be run can also be a security risk, if user is not always trusted).
Just be very careful with escaping. For example, when you test the command form command line, and then copy-paste it to C++ string literal, you need to escape every " and \ one more time for C++. If you have trouble with this, check out C++11 raw strings.
Escaping becomes extra important if you construct the command string at runtime, and especially if you accept user input and add that to the string. In that case, better search for and use some existing library like GLib, or sanitize the user input very carefully (ie. just paranoidically reject anything with chars, which may have a special meaning in shell in some context).
If you are actually asking, how can my program open a console window for itself similar to how Windows console programs behave, and redirect it's own stdin, stdout and stderr there, as if it was launched from command line, that that is not very easy from the same binary, and it is not commonly done like that in Unix.
If you want a behaviour like that, you could create a desktop shortcut, but more general way is to write a wrapper shell script, which starts your binary in a terminal. What kind of script exactly, depends on how you want it to behave exactly: what will it do with stdio, will it return or wait for program to exit, how do you want it to find the binary, how does it behave when run from command line instead of double-clicking from GUI, etc.
I am MFC guy working on visual studio 2010 create some executables using visual studio!! but on linux and mac my executables are not working as usual windows!!.
So i decided to use "MinGW" compiler to create executables.
Note:-Please give me one suggestion is that," is minGW is best compiler for cross plateform working ??or any thing else is there??"
I successfully install WinGW compiler on my C drive and start working with following program..
#include <iostream>
using namespace std;
int main ()
{
cout << "Hello ";
return 0;
}
I compile it using following command,
g++ -static-libgcc -static-libstdc++ Main.cpp
I found one executable in same folder with name a.exe :).Working fine:)
But after some time i decide to modified same program in following manner like,
int main ()
{
return 0;
}
I compile it with same command but when i execute it using command line it show me error "Access is denied so i goto that folder and run same executable as "Run as Administrator" it show me one messagebox with the message windows cannot access the specified device path or file. you may not have appropriate permissions
---EDIT--
follwing code is NOT WORKING:-
int main ()
{
int k;
return 0;
}
but this program WORKING :-
int main()
{
int k;
k = 0;
return 0;
}
If you are getting this access denied error, then the most likely cause is that the executable file is open in another process, probably the linker or debugger. Try installing Process Explorer and hit Ctrl+F and type in the name of your .exe. This should show the processes that the .exe file open. Kill those processes (or if you are still debugging, then end debugging first). You then should be able to build again.
Note that this has nothing to do with Microsoft APIs, as in any case you're using gcc.
EDIT: If there are no processes holding the .exe then it may be that there is some other kind of permission problem. Does the .exe file exist? Can you delete the file and rebuild? Another thing to try is run Process Monitor and filter for the name of the .exe -- that may show a regular permission denied error, or perhaps another error such as a sharing conflict.
Note:-Please give me one suggestion is that," is minGW is best compiler for cross plateform working ??or any thing else is there??"
No. And there's nothing else out there.
Use whatever compiler is available on target platform, ensure your code compiles on all of them.
Avoid platform-specific and compiler-specific code at all costs (use cross-platform frameworks).
I successfully install WinGW
There are many different versions of mingw provided by different sites. If you install compiler from mingw.org using mingw-get, it'll probably work. If you install mingw from some other site, it may or may not work.
I compile it using following command,
Use a build systems. cmake, qmake or something similar.
it show me error "Access is denied
Launch process monitor and see after which system call it terminates. It is also possible that your antivirus software interferes with your program, or maybe there's some stray dll in your path or something like that.
Check the permissions for the entire folder in which the executable resides. Trying to 'Run as Administrator' doesn't have any effect if the folder doesn't allow the permissions.
It doesn't have anything to do with your code. This is an environmental problem, something is pretty messed up about the permissions your user account has for one or more of the directories on your hard disk. The generic diagnostic is that the default working directory for the program does not permit read or list access.
A possible starting point would be to use Explorer and right-click the directory where MinGW is installed. Use the Security tab and ensure that your user account has all permissions enabled. Further narrow it down to trying to run the program from the command prompt, using different directories as the default directory.
Linux seems to be easy: xdg-open <file/directory/URL>.
Apparently, Mac is similar: open should be used instead of xdg-open. I don't have access to a Mac so I couldn't test it.
For Windows, I found 4 different suggestions and those that I have tried failed.
Is there a non-java, cross platform way to launch the associated application for a certain file type?
suggests start
How to give focus to default program of shell-opened file, from Java? suggests
cmd /c start ...
How to open user system preferred editor for given file?
How to Find Out Default File Opener with Java?
suggest RUNDLL32.exe
What is the correct way to use ShellExecute() in C to open a .txt
Open file with Windows' native program within C++ code
How to use ShellExecute to open html files in Windows using C++? suggest
ShellExecute
I have tried the first 3 with system() and QProcess::startDetached() and "http://www.stackoverflow.com" as argument but they all failed; start works just fine from the command line though. I haven't tried ShellExecute yet.
What is the Windows equivalent of xdg-open? It seem to me, it is start but why did my attempts with start fail?
Is ShellExecute my only option?
EDIT I thought QDesktopServices::openUrl() was for web pages only because it did not work for files or directories.
After some debugging I figured out that if I replace \\ with / in the path on Windows, it works for files but the directories are still not opened. Any ideas what I am doing wrong?
QDir dir("C:/Documents and Settings/ali");
qDebug() << "Exists? " << dir.exists();
qDebug() << dir.absolutePath();
QDesktopServices::openUrl(QUrl(dir.absolutePath()));
qDebug() << "External app called";
Application Output:
Exists? true
"C:/Documents and Settings/ali"
External app called
But nothing happens, the directory is not opened. On Linux, directories are opened with the default file manager as expected.
SOLUTION: Due to the Qt bug and Windows quirks (malformed application window), I ended up using ShellExecute. That gives me enough flexibility to achieve exactly what I want at some expense...
Why don't you just use Qt's support for this? For example:
QDesktopServices::openUrl(QUrl("/home/realnc/test.pdf"));
This opens the document in Acrobat Reader. In general, it obeys the preferred application settings in my OS for all file types that have one or more applications associated with them. Best of all, it's platform-independent.
Edit:
The fact that it opens directories on Linux but not on Windows smells like a bug. It might be best to report this on Qt's bug tracker. In the meantime, you could have a workaround for Windows for when the file is a directory:
#ifdef Q_WS_WIN
if (QFileInfo(path).isDir())
QProcess::startDetached("explorer", QStringList(path));
else
#endif
QDesktopServices::openUrl(QUrl(path));
You can also do it with cmd.exe's start command, but you'll get an ugly terminal pop up for a few fractions of a second:
QProcess::startDetached("cmd", QStringList() << "/C" << "start"
<< QDir::toNativeSeparators(path));
I'm using VS2010 and I would like to call an exe file which I've created in another directory.
I've tried the following:
int main(){
system("C:\\Users\\Li\\Desktop\\Debug\\modelExample_4pcs.exe");
return 0;
};
but I get "The system could not find the file specified" error.
I've tried to run the exe file directly from the command line, and it only works when I'm inside its directory.
Could you please tell me how can I run it from a different directory?
(I'm using win7)
Thanks,
Li.
You should try using CreateProcess Windows API funcion: http://msdn.microsoft.com/en-us/library/ms682425%28VS.85%29.aspx
Try opening the file for reading, just to check that you have the path right:
char* filename = "C:\\Users\\Li\\Desktop\\Debug\\modelExample_4pcs.exe" ;
FILE* fp = fopen (filename, "rb") ; // Open for reading, binayr mode
if (fp == 0) {
printf ("Duh! File not found\n") ;
exit (0) ;
}
printf ("File found\n") ;
fclose (fp) ;
// Now try the system call, as before:
system(filename);
What happens?
You should be able to use ShellExecute like so: (adjusting the params sent to ShellExecute for your situation) http://msdn.microsoft.com/en-us/library/bb762153(VS.85).aspx?ppud=4
HINSTANCE hinst = ShellExecute( NULL, _T("open"), commandLine.c_str(), additionalParams.c_str(), NULL, SW_RESTORE );
if(hinst <= (HINSTANCE)SHELLEXERROR)// see: http://msdn2.microsoft.com/en-us/library/bb762153.aspx for further info on the return values
Now given that you are using Win7, you may be having a privilege issue and you need to run at an elevated level (i.e. administrator) you can test this by opening cmd as admin and running your exe from another directory
and as Steve mentioned above you can certainly use CreateProcess.
HTH,
EB
System() may not be able to find cmd.exe to open your environment.
Try using cmd.exe to execute your app via the /C option.
System("C:\\WINDOWS\\system32\cmd.exe /C \"C:\\Users\\Li\\Desktop\\Debug\\modelExample_4pcs.exe\"");
Try this using CreateProcess. Less (or at least different) environmental dependencies than using system(). At least you will get a nice Win32 error code if this still fails.
http://msdn.microsoft.com/en-us/library/ms682425(VS.85).aspx
Check your path, and make sure you escape all characters: C:\\Users\Li..
Is the error from running the main program, not from launching modelExample_4pcs.exe? Try commenting out the system() call and see if you get the same error.
Your main program is not on the path when you're outside its folder...
Is modelExample_4pcs.exe trying to load another file from the current working folder, and THAT's what's generating the error?
Maybe try chdir() before the call to system().
Just change to the directory first, like you would do from the command prompt:
system("C: && CD \\Users\\Li\\Desktop\\Debug\\ && modelExample_4pcs.exe");