How to execute extreme long command with C++? - c++

Question

I am trying to execute quite long external command (curl with long parameters) in my C++ program.
Works fine on Linux, but Windows (under Cygwin) always shows "System cannot execute specified program" if "cmd" is longer than 127 chars.
Linux accepts with same code almost unlimited size.
Tried changing size of buffer, no change.
Used this code:
#include <string>
#include <iostream>
#include <stdio.h>
std::string exec(char* cmd) {
FILE* pipe = _popen(cmd, "r");
if (!pipe)
return "ERROR";
char buffer[128];
std::string result = "";
while(!feof(pipe)) {
if(fgets(buffer, 128, pipe) != NULL)
result += buffer;
}
_pclose(pipe);
return result;
}
Is that Windows specific limitation, or is possible somehow to extend the cmd buffer?
Added how is created char* which I am trying to send:
string message="This is message to send.";
std::string send="";
std::string curl_header="curl -s -F \"token=aE71iieVt8G1RWdJb59qmAa3hbxxxx\" -F \"user=uPKYQyNgGURbH1g56nBnjn9jNsxxxxx\" -F \"message=";
send.append(curl_header);
send.append(message);
send.append("\" https://api.pushover.net/1/messages.json");
cout << "\n";
cout << "FULL STRING WITH PARAMS TO EXECUTE:";
std::cout << send << '\n';
char *cstr = new char[send.length() + 1];
strcpy(cstr, send.c_str());
cout << "FULL CHAR ARRAY WITH PARAMS TO EXECUTE:";
std::cout << cstr << '\n';//this returns correct string, even longer than 127 chars
cout << exec(cstr);// this returns error, same with system() if cstr is longer than 127 chars
delete [] cstr;

Answer 1

Have you tried using system?
#include <iostream>
using namespace std;
int main(int argc,char** args){
if(argc<2){
system("run run run run run run run run run run runr urn runrunrunru unr unrunr urn run runr unr urn run runrun runr unr urnrun runr urnurnrunrunrunrunrunrurn urnurnunrunrunrunrunrunrn u unru ru runr ur urn ru run rururnunrunrunr");
}else{
printf("argc: %d",argc);
}
system("pause");
}
This seems to work fine to me. The program is named run, so it runs itself with that huge argument and then prints out the number of arguments it sees. Is this what you are trying to do?