Below is my c++ code and my config file.
when I run spawn-fcgi -a120.0.0.1 -p9000 -n ./rtb.o
I get this error
spawn-fcgi: exec failed: Exec format error
Here is my c++ code that I complied as rtb.o
#include "fcgi_stdio.h"
#include <stdlib.h>
using namespace std;
int main()
{
int count = 1;
while(FCGI_Accept() >= 0)
printf("Content-type: text/html\r\n"
"\r\n"
"<title>FastCGI Hello!</title>"
"<h1>FastCGI Hello!</h1>"
"Request number %d running on host \n",
++count);
return 0;
}
So, what did I do wrong?
You're attempting to run a program called rtb.o? Is this an object file or an executable? You might want to show us how you compile your program. If you're doing something like
g++ -c rtb.cpp
Then you will get an object file and you need to link it to get a working program. Try to run it from your terminal using ./rtb.o. If it prints the same message, then you've got an object file and need to try something like this instead:
g++ -o rtb rtb.cpp
Remember to add a reference to the FCGI library when you link (use the -l option).
Related
This question already has answers here:
Why do I get no output for very simple Hello World program?
(7 answers)
Closed 6 months ago.
I am new to C++ and coded my first main.cpp but I got an error, not exactly an error, it is a logical error, I guess because I wrote the following code:
#include <iostream> // including the iostream
using namespace std; // using the std namespace
int main() { // starting the main function
cout << "Hello World!" << endl; // My favorite line of code in all the of languages
return 0; // returning 0 to stop the function execution
}
In the terminal I expected
C:\Users\DELL\Desktop> g++ main.cpp
Hello World!
C:\Users\DELL\Desktop>
But it is just showing:
C:\Users\DELL\Desktop> g++ main.cpp
C:\Users\DELL\Desktop>
No output is coming, but when I try in Code::Blocks, it is working just fine! In vscode terminal, the same problem but when I run the file, it is working again! Why is it not working? I tried it in Command Prompt, installed the Windows Terminal, and tried it in that also (keeping the terminal as Command Prompt, cause I don't know what PowerShell is and how to use it) but any method is not working.
Please tell me what to do, I am new to c++ and know only some things amount it.
The command g++ main.cpp creates the file a.out or a.exe. After that file is created you need to run it by the command ./a.out on Linux and Mac or a.exe on Windows.
It's pretty simple, after g++ "file.cpp", you get an output file in your current working directory, which is the executable. C++ is compiled, not interpreted.
That output file is the executable, which by default will be "a.out", with gcc/g++. You can use the option "-o" to specify the output directory.
g++ main.cpp will compile the file and produce a.exe, you just need to type a.exe in the terminal and it will print Hello World!.
I wanted to execute code in terminal not in debugger
After downloading all the c/c++ extension in vs-code.
code
#include<iostream>
using namespace std;
int main()
{ int UserInputOccur;
cout<<"helloworld";
cin>>UserInputOccur;
cout<<UserInputOccur;
return 0;
}
All the compilation and debugging done in debug console only till
( First user input i.e When first cin>>UserInputOccur; and then the code in terminated with helloworld1020=thread-exited,id="3",group-id="i1"
If you are using Linux you can write your code in a file, such as main.cpp.
Then you can open terminal -> go to the directory of the file -> run command g++ main.cpp -o main.
Now you can run your code on terminal with command ./main
i downloaded gsoap 2.8.14, configure and install with the following commands:
./configure --disable-ssl --enable-samples --enable-debug
make
make install
im tried to compile gsoap sample "hello". so i took the the wsdl file from the sample and did the following:
wsdl2h -s -o hello.h h.wsdl
soapcpp2 hello.h
i copied the generated files into a new eclipse c++ project and excluded soapClientLib.cpp and soapServerLib.cpp because i was receiving errors like
multiple definition of .....
i then created a helloserver.cpp and here is the content:
#include "soapH.h"
#include "Service.nsmap"
int main()
{
return soap_serve(soap_new);
}
int __ns1__hello(struct soap *soap, char* helloReq, char* &helloResponse)
{
return SOAP_OK;
}
when i build in eclipse, i receives an error:
...soapServer.cpp:77 undefined reference to __ns1__hello(soap*,_ns2_hello*, _ns__helloResponse*)
when i trace to soapServer.cpp, this line is getting the error:
soap->error=__ns1_hello(soap,soap_tmp___ns1_hello.ns2__hello,&ns2__helloResponse);
why am i getting this error? im using the sample hello wsdl from gsoap
Well as you can see from the error message (and the soapServer.cpp code) you are supposed to write a function
int __ns1__hello(struct soap *soap,
_ns2_hello* helloReq,
_ns__helloResponse* helloResponse)
{
return SOAP_OK;
}
not the function you wrote.
Here is the code I have- not sure why I am getting this error message:
$ ./main.cpp "hello" "is"
./main.cpp: line 4: syntax error near unexpected token `('
./main.cpp: line 4: `int main(int argc, char *argv[]){'
It compiles fine in g++, but when I run it, I get the above error. Any idea why? Here is my complete code..
#include <iostream>
#include <fstream>
int main(int argc, char *argv[]){
for(int i = 0; i < argc; i++){
std::cout << argc << " : " << argv[i] << '\n';
}
if (argc != 2){
std::cout << "\nUSAGE: 2 command line arguments please." << std::endl;
std::cout << "\n (1) Input file with raw event scores.\n (2) Output file to write into.";
}
// open the font file for reading
std::string in_file = argv[1];
std::ifstream istr(in_file.c_str());
if (!istr) {
std::cerr << "ERROR: Cannot open input file " << in_file << std::endl;
}
return 0;
}
You have to run the compiled program, not the source code:
$ g++ -o main main.cpp
$ ./main "hello" "is"
3 : ./main
3 : hello
3 : is
USAGE: 2 command line arguments please.
(1) Input file with raw event scores.
(2) Output file to write into.ERROR: Cannot open input file hello
Your example is trying to execute C++ code as a shell script, which isn't going to work. As you can see from the output of my test run of your program here, you still have some bugs to work out.
As both the other answers say, you're running it as a shell script, implicitly using /bin/sh.
The first two lines starting with # are treated by the shell as comments. The third line is blank, and does nothing. The fourth line is interpreted as a command int, but parentheses are special to the shell, and are not being use correctly here. There probably isn't an int command in your $PATH, but the shell doesn't get a chance to report that because it chokes on the syntax error.
None of these details are particularly important; the problem is that you're executing the program incorrectly. But it might be interesting to see why those specific error messages are printed.
And it appears that you've done something like chmod +x main.cpp; otherwise the shell would have refused to try to execute it in the first place. Making a C++ source file executable isn't going to cause any real harm (as long as it's readable and writable), but it's not at all useful, and as you've seen it delayed the detection of your error. If you do chmod -x main.cpp, and then try ./main.cpp again, you'll get a "Permission denied" error instead.
As Carl's answer says, you need to execute the executable file generated by the compiler, not the C++ source file. That's why there's a compiler. The compiler (well, actually the linker) will automatically do the equivalent of chmod +x on the executable file it generates.
The file command will tell you what kind of file something is, which affects what you can do with it. For example, using your code on my system, after running g++ main.cpp -o main:
$ file main.cpp
main.cpp: ASCII C program text
$ file main
main: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0xacee0dfd9ded7aacefd679947e106b500c2cf75b, not stripped
$
(The file command should have recognized main.cpp as C++ rather than as C, but sometimes it guesses wrong.)
"ELF" is the executable format used by my system; the file contains executable machine code plus some other information. The pre-installed commands on the system use the same format.
The details may differ on your system -- and will differ substantially on non-Unix-like systems such as MS Windows. For example, on Windows executable files are normally named with a .exe extension.
The compiler, by default, creates an executable called "a.out", so you want to do:
$ a.out "hello" "is"
Typing "./main.cpp" is trying to execute the C++ source file, probably as a shell script
hi every body i have a strange problem i write a code in c++ complied it successfully and run it successfully. i compiled with following command
g++ 1.c -o abc
to run program i use ./abc
now my problem is that i write a another code in c++ like
#include <fstream>
#include<iostream>
using namespace std;
int main()
{
ofstream SaveFile("/home/hadoop/project/hadoop-0.20.0/conf/core-site2.xml");
SaveFile <<"<configuration>";
SaveFile<<endl;
SaveFile<<"<property>";
SaveFile<<endl;
savefile.close();
return 0;
}
now i want to run abc in this code how to do this ?
how to use or run abc in this file?
how to use ./abc in this program ?
Actually, your question title ("... using system ...") says it all. Use:
system ("./abc");
to run the ./abc program.
There are other ways to run programs from within a program (which usually depend on platform-specific features) but this is the most portable.
A full sample program, testprog.cpp, to show what I mean:
#include <cstdlib>
int main (void) {
std::system ("ls -ald m*");
return 0;
}
Compiling this with:
g++ -Wall -Wextra -pedantic -o testprog testprog.cpp
and running the resultant executable testprog, this outputs (on my Ubuntu 10.04 box):
drwxr-xr-x 2 pax pax 4096 2010-12-14 09:33 myfolder
In other words, it runs the ls -ald m* command from within the program itself.