Is there any way to run a java (.jar) program from a C or C ++ program?

The most standard solution would be to use the system() function of the default library stdlib.h .

BUT , from the point of view of *nix systems, the use of system() should be avoided:

  

1 - The call of the system() function executes the command interpreter   (shell), which makes it much slower than calling a fork()   followed by exec() ;

     

2 - This is a potential security risk if you pass as a parameter   an untrusted source string;

     

3 - Can not be used asynchronously, ie the system is   blocked waiting for the child process to return;

     

4 - Double fork() and exec() give us much more control before and between your   calls.

The following example exemplifies running .jar using fork() , exec() , and waitpid() calls on a Linux system.

Note that the child process prepares the environment by redirecting the output streams ( exec() and STDERR ) to two output files: STDOUT and stderr.txt .

The parent process stream is purposely blocked with the stdout.txt call, but could be "working" on another task:

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#define MAX_CMD_TAM  (1024)

int main( int argc, char * argv[] )
{
    char cmd[ MAX_CMD_TAM + 1 ] = {0};

    /* Verifica se o nome de arquivo .jar foi passado como parametro na linha de comando */
    if( argc != 2 )
    {
        printf("Erro de sintaxe: %s [ARQUIVO_JAR]\n", argv[0] );
        return 1;
    }

    /* Processo pai cria uma copia de si mesmo (cria um processo filho) */
    pid_t child = fork();

    /* Monta a linha de comando que sera executada */
    snprintf( cmd, MAX_CMD_TAM, "java -jar %s", argv[1] );

    if( child == 0 ) /* Fluxo do processo filho */
    {
        /* Abre/Cria arquivos para substituirem as saidss padroes: STDOUT e STDERR */
        int fdout = open( "stdout.txt", O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR );
        int fderr = open( "stderr.txt", O_RDWR | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR );

        /* Redireciona o STDOUT e STDERR para os arquivos correspondentes */
        dup2( fdout, STDOUT_FILENO );
        dup2( fderr, STDERR_FILENO );

        /* Depois de duplicados, os descritores dos arquivos nao sao mais necessarios */
        close(fdout);
        close(fderr);

        /* Executa comando */
        execlp( cmd, NULL );
    }
    else if( child > 0 ) /* Fluxo do processo pai */
    {
        /* Processo pai aguarda a execucao do processo filho */
        printf( "Executando Comando: \"%s\"\n", cmd );

        printf( "Aguardando a execucao do processo filho...\n");
        waitpid(child);

        printf("Sucesso!\n");
    }
    else
    {
        printf("fork() falhou!\n");
        return 1;
    }

    return 0;
}

/* fim-de-arquivo */

I hope I have helped!

You can use the command line ( system() ):

 java -jar "arquivo.jar"

Depending on what you want to do, you can use JNI . It's pretty complicated.