Add missing file util.h to tree

Author: BatchDrake

util/units.h

@@ -0,0 +1,77 @@
+/*
+
+  Copyright (C) 2025 Gonzalo José Carracedo Carballal
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation, version 3.
+
+  This program is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this program.  If not, see
+  <http://www.gnu.org/licenses/>
+
+*/
+
+#ifndef _UTIL_UNITS_H
+#define _UTIL_UNITS_H
+
+#include <sigutils/types.h>
+#include <string.h>
+
+SUINLINE const char *
+suscan_units_format_frequency(SUFREQ freq, char *buf, size_t size)
+{
+  if (freq < 1e3)
+    snprintf(buf, size, "%.0lf Hz", freq);
+  else if (freq < 1e6)
+    snprintf(buf, size, "%.3lf kHz", freq * 1e-3);
+  else if (freq < 1e9)
+    snprintf(buf, size, "%.6lf MHz", freq * 1e-6);
+  else if (freq < 1e12)
+    snprintf(buf, size, "%.9lf GHz", freq * 1e-9);
+  else
+    snprintf(buf, size, "%.12lf THz", freq * 1e-12);
+
+  return buf;
+}
+
+
+SUINLINE const char *
+suscan_units_format_time(SUFLOAT delta, char *buf, size_t size)
+{
+  unsigned int hour, min, sec;
+  SUFLOAT decim;
+
+  if (delta > 1) {
+    sec = SU_FLOOR(delta);
+    decim = delta - sec;
+
+    hour = sec / 3600;
+    min  = (sec / 60) % 60;
+    sec %= 60;
+  }
+
+  if (delta < 1e-9)
+    snprintf(buf, size, "%.3g ps", delta * 1e12);
+  else if (delta < 1e-6)
+    snprintf(buf, size, "%.3g ns", delta * 1e9);
+  else if (delta < 1e-3)
+    snprintf(buf, size, "%.3g us", delta * 1e6);
+  else if (delta < 1)
+    snprintf(buf, size, "%.3g ms", delta * 1e3);
+  else if (delta < 60)
+    snprintf(buf, size, "%.3g s", delta);
+  else if (delta < 3600)
+    snprintf(buf, size, "00:%02d:%02d.%.3g", min, sec, decim);
+  else
+    snprintf(buf, size, "%02d:%02d:%02d", hour, min, sec);
+
+  return buf;
+}
+
+#endif /* _UTIL_UNITS_H */