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/* Code to extract elements for high-flying artsats. Give */
/* it the name of the input file of TLEs and a cutoff of */
/* the mean motion, and only TLEs with a lower motion */
/* will be output. */
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include "norad.h"
int main( const int argc, const char **argv)
{
FILE *ifile = fopen((argc > 1 ? argv[1] : "all_tle.txt"), "rb");
FILE *ofile;
char line0[200], line1[200], line2[200];
const double cutoff = (argc > 2 ? atof( argv[2]) : .6);
const time_t t0 = time( NULL);
if( !ifile)
perror( "Input file not opened");
ofile = (argc > 3 ? fopen( argv[3], "a") : stdout);
if( !ofile)
perror( "Output file not opened");
if( !ifile || !ofile)
return( -1);
*line0 = *line1 = '\0';
fprintf( ofile, "# Added %s\n", ctime( &t0));
while( fgets( line2, sizeof( line2), ifile))
{
if( *line2 == '2' && *line1 == '1'
&& !tle_checksum( line1) && !tle_checksum( line2)
&& atof( line2 + 52) < cutoff)
fprintf( ofile, "%s%s%s", line0, line1, line2);
strcpy( line0, line1);
strcpy( line1, line2);
}
fclose( ifile);
return( 0);
}
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