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#if 0
/*─────────────────────────────────────────────────────────────────╗
│ To the extent possible under law, Justine Tunney has waived │
│ all copyright and related or neighboring rights to this file, │
│ as it is written in the following disclaimers: │
│ • http://unlicense.org/ │
│ • http://creativecommons.org/publicdomain/zero/1.0/ │
╚─────────────────────────────────────────────────────────────────*/
#endif
#include "libc/bits/bits.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/itimerval.h"
#include "libc/fmt/conv.h"
#include "libc/limits.h"
#include "libc/log/check.h"
#include "libc/log/color.internal.h"
#include "libc/log/log.h"
#include "libc/math.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/sysv/consts/itimer.h"
#include "libc/sysv/consts/sig.h"
#include "libc/time/time.h"
static const struct itimerval kTimer = {{0, 10000}, {0, 10000}}; /* 10ms */
static volatile bool32 showprogress_;
static const char *magic_;
void OnInterrupt(int sig) {
showprogress_ = true;
}
void ShowProgress(uintmax_t i, uintmax_t j, uintmax_t n) {
fprintf(stderr, "%s%,40jd%,40jd%,40jd\r\n", magic_, i, j, n);
showprogress_ = false;
}
static bool IsPrime(uintmax_t i) {
uintmax_t j, n;
for (j = 3, n = (unsigned long)floorl(sqrtl(i)); j <= n; j += 2) {
if (showprogress_) ShowProgress(i, j, n);
if (i % j == 0) return false;
}
return true;
}
static void TryNumber(uintmax_t x, uintmax_t i) {
if (IsPrime(i)) {
printf("%s%,jd%s%,jd\n", "the prime nearest ", x, " is ", i);
exit(0);
}
}
int main(int argc, char **argv) {
uintmax_t x, i, j;
CHECK_EQ(2, argc);
signal(SIGALRM, OnInterrupt);
setitimer(ITIMER_REAL, &kTimer, NULL);
magic_ = cancolor() ? "\e[F\e[K" : "";
if ((x = strtoumax(argv[1], NULL, 0)) % 2 == 0) ++x;
TryNumber(x, x);
for (i = x, j = x;;) {
if (i < UINTMAX_MAX) TryNumber(x, i), i += 2;
if (j > 1) TryNumber(x, j), j -= 2;
}
}