// Read the GPS files
void ReadGPSFiles(gps_type *GPS, double StartMJD)
{
int i, Done;
FILE *IO;
char line[MaxChars];
float MJD, ClockOffset_read;
float MJD_prev=0, ClockOffset_read_prev;
float ClockOffset_Ref;
double ClockDrift_Ref;
Done = 0;
GPS->ClockDrift=0;
printf("Opening GPS file %s\n", GPS->filename);
IO = Sopen(GPS->filename, "r");
while (fgets(line, MaxChars, IO) && !Done) {
if (line[0] != '#') {
sscanf(line, "%f %f", &MJD, &ClockOffset_read);
if (StartMJD < MJD) {
GPS->ClockOffset = (ClockOffset_read - ClockOffset_read_prev) * (StartMJD-MJD_prev)/(MJD-MJD_prev) + ClockOffset_read_prev;
GPS->ClockDrift += (ClockOffset_read - ClockOffset_read_prev)/86400; // in us / s
Done = 1;
}
MJD_prev = MJD;
ClockOffset_read_prev = ClockOffset_read;
}
}
if (!Done) {fprintf(stderr, "Can't get clockoffset!\n"); GPS->ClockOffset = 0;}
if (GPS->ClockOffset == 0) {
fprintf(stderr, "Could not find Clockoffset with MJD=%f in %s\n", StartMJD, GPS->filename);
exit(0);
}
// Read the reference clock.
Done = 0;
ClockDrift_Ref=0;
IO = Sopen(GPS->filenameref, "r");
while (fgets(line, MaxChars, IO) && !Done) {
if (line[0] != '#') {
sscanf(line, "%f %f", &MJD, &ClockOffset_read);
if (StartMJD < MJD) {
ClockOffset_Ref = (ClockOffset_read-ClockOffset_read_prev) * (StartMJD-MJD_prev)/(MJD-MJD_prev) + ClockOffset_read_prev; // in us, gets converted to s
ClockDrift_Ref += (ClockOffset_read - ClockOffset_read_prev)/86400; // in us / s, gets converted to s / s
Done = 1;
}
MJD_prev = MJD;
ClockOffset_read_prev = ClockOffset_read;
}
}
if (!Done) {fprintf(stderr, "Can't get clockoffset!\n"); ClockOffset_Ref = 0;}
if (ClockOffset_Ref == 0) {
fprintf(stderr, "Could not find Clockoffset with MJD=%f in %s\n", StartMJD, GPS->filenameref);
exit(0);
}
// Move reference of clockoffset and clockdrift to telescope 0, so that telescope 0 has no offset and no drift
GPS->ClockOffset -= ClockOffset_Ref;
GPS->ClockDrift -= ClockDrift_Ref;
// Convert to seconds. Positive value means the telescope is early.
GPS->ClockOffset /= 1e6; // in s
GPS->ClockDrift /= 1e6; // in s/s
}
// Read Calc file
// The first time this is called, set SetCountCalcSteps to 1. This will then determine how far into the calc file to read.
// The next times this routine is called, CountCalcSteps should be increased by 1 before calling and SetCountCalcSteps should be 0
// Skipsamples contains the skipsamples from the input + skipsamples to skip to the starttime of the last telescope + clockdelays
// Samptime is in seconds
void ReadCalcfile(calc_type *Calc, double StartMJD, long Skipsamples, double SampTime, int SetCountCalcSteps)
{
int i, j, MJDint, MJDsec;
double Refdelay, RefTelPoly[NPOLYS];
FILE *IO;
char line[MaxChars], Dummy[MaxChars];
int RefTel = 0;
int NTelescopes = 2;
printf("Opening Calcfile %s\n", Calc->filename);
IO = Sopen(Calc->filename, "r");
for (i=0; i<18+NTelescopes; i++) fgets(line, MaxChars, IO); // Skip first lines
fgets(line, MaxChars, IO); // Get Calc MJDint
sscanf(line, "%18c %d\n", Dummy, &MJDint);
fgets(line, MaxChars, IO); // Get Calc MJDsec
sscanf(line, "%18c %d\n", Dummy, &MJDsec);
Calc->CalcMJD = MJDint + MJDsec/86400.;
// Calc offset (double) between start of calc and start of correlations in seconds with respect to reference telescope
if (SetCountCalcSteps) {
Calc->Offset = (Calc->CalcMJD - StartMJD)*86400 + Skipsamples*SampTime;
Calc->CountCalcSteps = (int)(Calc->Offset/CALCSTEPSIZE);
}
// Read polynomials. First for reftel.
for (i=0; i<(2*6*NTelescopes+2)*Calc->CountCalcSteps; i++) fgets(line, MaxChars, IO); // Skip to right timesection
fgets(line, MaxChars, IO);
sscanf(line, "%23c %lf %lf %lf %lf %lf %lf", Dummy, &RefTelPoly[0], &RefTelPoly[1], &RefTelPoly[2], &RefTelPoly[3], &RefTelPoly[4], &RefTelPoly[5]);
// printf("%e %e %e %e %e %e\n", RefTelPoly[0], RefTelPoly[1], RefTelPoly[2], RefTelPoly[3], RefTelPoly[4], RefTelPoly[5]);
for (j=0; j<5; j++) fgets(line, MaxChars, IO);
fgets(line, MaxChars, IO);
sscanf(line, "%23c %lf %lf %lf %lf %lf %lf", Dummy, &Calc->Poly[0], &Calc->Poly[1], &Calc->Poly[2], &Calc->Poly[3],
&Calc->Poly[4], &Calc->Poly[5]);
//printf("%e %e %e %e %e %e\n", Calc->Poly[0], Calc->Poly[1], Calc->Poly[2], Calc->Poly[3], Calc->Poly[4], Calc->Poly[5]);
for (j=0; j<5; j++) fgets(line, MaxChars, IO);
fclose(IO);
for (j=0; j<NPOLYS; j++)
Calc->Poly[j] -= RefTelPoly[j]; // Subtract reference
for (j=0; j<NPOLYS; j++)
Calc->Poly[j] /= 1e6; // Convert from us to seconds
}
/* main: */
int main(
int argc,
char **argv)
{
int sktcnt = 0;
int istat;
int ret;
Socket *srvr = NULL;
Socket *nskt = NULL;
if(argc <= 1) {
fprintf(stderr,"***usage*** sktfork srvrname\n");
exit(1);
}
srvr= Sopen(argv[1],"s");
if(!srvr) {
fprintf(stderr,"***error*** unable to open <%s> server\n",argv[1]);
exit(1);
}
/* install a SIGCHLD handler */
sigset(SIGCHLD,sigchld_handler);
while(1) {
printf("Wait for new socket to be accepted\n");
nskt= Saccept(srvr);
if(!nskt) { /* presumably I just got a SIGCHLD */
printf("WEXITSTATUS(childstat=%d)=%d\n",childstat,WEXITSTATUS(childstat));
if(WEXITSTATUS(childstat) == 1) break;
continue;
}
else {
++sktcnt;
printf("normal new skt: sktcnt=%d\n",sktcnt);
}
ret= fork();
if(ret == 0) {
/* child process */
char buf[BUFSIZE];
Socket *skt;
printf("child() skt<%s>",Sprtskt(nskt));
skt = nskt;
nskt= NULL;
if(!Sgets(buf,BUFSIZE,skt)) {
fprintf(stderr,"***error*** unable to Sgets\n");
_exit(0);
}
Sputs("goodbye!",skt);
printf("got <%s>, goodbye!\n",buf);
Sclose(skt);
skt= NULL;
if(!strcmp(buf,"Q")) {
printf("return: child 1");
_exit(1);
}
printf("return: child 0");
_exit(0);
}
else if(ret == -1) {
fprintf(stderr,"***error*** unable to fork\n");
if(nskt) Sclose(nskt);
if(srvr) Sclose(srvr);
srvr= nskt= NULL;
break;
}
}
printf("closing down server: sktcnt=%d\n",sktcnt);
if(srvr) Sclose(srvr);
srvr= NULL;
return 0;
}