```/* nag_prob_students_t (g01ebc) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.1, 2017.
*
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <nagg01.h>

int main(void)
{
Integer exit_status = 0;
double df, prob, t;
int i;
static Nag_TailProbability tail[4] = { Nag_LowerTail, Nag_UpperTail,
Nag_TwoTailSignif, Nag_TwoTailConfid
};
static const char *tailmess[] = { "Nag_LowerTail", "Nag_UpperTail",
"Nag_TwoTailSignif",
"Nag_TwoTailConfid"
};
NagError fail;

INIT_FAIL(fail);

printf("nag_prob_students_t (g01ebc) Example Program Results\n\n");
/* Skip heading in data file */
scanf("%*[^\n]");
printf("    t      df     prob      tail\n\n");
while (scanf("%lf %lf %d\n", &t, &df, &i) != EOF)
{
/* nag_prob_students_t (g01ebc).
* Probabilities for Student's t-distribution
*/
prob = nag_prob_students_t(tail[i], t, df, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_prob_students_t (g01ebc).\n%s\n", fail.message);
exit_status = 1;
goto END;
}
printf(" %6.3f%8.3f%8.4f  %s\n", t, df, prob, tailmess[i]);
}

END:
return exit_status;
}
```