sprog/sprog.c

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/select.h>
#include <sprog.h>

void sprog_process(const struct sprog_family *fam, void *arg, int nstdin, int nstdout);

void sprog_error(const char *text, ...) {
  va_list l;
  va_start(l, text);
  vfprintf(stderr, text, l);
  va_end(l);
}

void sprog_sleep(int msec) {
  usleep(msec * 1000);
}

void sprog_communicate(const struct sprog_family *fam, const char *port, int baud) {
  int pstdin[2];
  int pstdout[2];
  int pid;
  void *arg;
  struct serial_device dev;
  
  serial_open(&dev, port, baud);
  arg = fam->setup(&dev);
  pipe(pstdin);
  pipe(pstdout);
  pid = fork();
  if(pid<0)
    sprog_error("Unable to fork: %s\n", strerror(errno));
  else {
    if(pid==0) {
      close(pstdin[0]);
      close(pstdout[1]);
      serial_communicate(&dev, pstdout[0], pstdin[1]);
      fam->close(arg);
    } else {
      close(pstdin[1]);
      close(pstdout[0]);
      sprog_process(fam, arg, pstdin[0], pstdout[1]);
    }
  }
}

int sprog_waitdata(int timeout) {
  fd_set read_set;
  struct timeval tval;
  FD_ZERO(&read_set);
  FD_SET(1, &read_set);
  tval.tv_sec = timeout/1000;
  tval.tv_usec = (timeout%1000)*1000;
  if(select(1+1, &read_set, NULL, NULL, &tval)!=1)
    return 0;
  return 1;
}

void sprog_process(const struct sprog_family *fam, void *arg, int nstdin, int nstdout) {
  dup2(nstdin, 0);
  dup2(nstdout, 1);
  fam->init(arg);
  exit(0);
}