gmt-makemap/test/gmttest.cpp

#include <gmt.h>
#include <iostream>
#include <string>
#include <unistd.h>
#include <sys/wait.h>

int print_func(FILE* fd, const char* str)
{
 std::cout<<"PRINT: "<<str<<std::endl;
 return 0;
}

struct gmtworkthreadpars
{
 void* api;
 const char* module;
 void* opts;
 int fd;
 int ret;
};

void* gmtworkthread(void* x)
{
 struct gmtworkthreadpars* p=reinterpret_cast<struct gmtworkthreadpars*>(x);
 char c='\n';

 //unshare(CLONE_FILES);
 //dup2(p->fd,1);
 //write(p->fd,&c,1);
 GMT_Append_Option(p->api,GMT_Make_Option(p->api,'>',const_cast<char*>(("/dev/fd/"+std::to_string(p->fd)).c_str())),reinterpret_cast<struct GMT_OPTION*>(p->opts));
 //write(p->fd,&c,1); // Use this instead of mutex
 p->ret=GMT_Call_Module(p->api,p->module,GMT_MODULE_OPT,p->opts);
 //close(1);
 close(p->fd);
 return 0;
}

int callgmtmodule(void *api, const char *module, void *opts, std::string& res)
{
 int pipefd[2];
 ssize_t br;
 char buffer[4096];
 pthread_t wthr;
 struct gmtworkthreadpars p;

 pipe(pipefd);
 p.api=api;
 p.module=module;
 p.opts=opts;
 p.fd=pipefd[1];

 pthread_create(&wthr,0,&gmtworkthread,&p);

 res.erase();
 read(pipefd[0],buffer,1);
 close(pipefd[1]);
 do
 {
  br=read(pipefd[0],buffer,4096);
  std::cout<<res.length()<<" "<<br<<std::endl;
  res.append(buffer,br);
 } while(0!=br);
 res.shrink_to_fit();
 pthread_join(wthr,0);
 return p.ret;
}


int main()
{
 char* text="GMT";
 //void* out;
 void* gmtapi;
 std::string args="-R130/160/40/60 -JM12c -Xa2c -Ya2c -B5/5/swNE --GMT_HISTORY=f --FONT_ANNOT_PRIMARY=14p,Times-Bold,red";
 struct GMT_OPTION* opts;
 int io,ret;
 char fname[16];
 std::string out;

 gmtapi=GMT_Create_Session(text,2,0,print_func);
 io=GMT_Register_IO(gmtapi,GMT_IS_TEXTSET,GMT_IS_DUPLICATE,GMT_IS_NONE,GMT_OUT,0,0);
 GMT_Encode_ID(gmtapi,fname,io);
 opts=GMT_Create_Options(gmtapi,0,(void*)args.c_str());
 //ret=GMT_Init_IO(gmtapi,GMT_IS_TEXTSET,GMT_IS_NONE,GMT_OUT,5,0,opts);
 std::cout<<io<<" "<<GMT_NOTSET<<" "<<fname<<" "<<ret<<std::endl;

 callgmtmodule(gmtapi,"psbasemap",opts,out);

 std::cout<<out.max_size()<<" "<<out.capacity()<<" "<<out.size()<<std::endl;

 GMT_Destroy_Options(gmtapi,&opts);
 GMT_Destroy_Session(gmtapi);

 return 0;
}