maxmin.sh

#!/bin/bash
# Find the max and the min for each device in a day's log.
# Log the output to a summary file.
if [[ -n "$1" ]]; then
  file="/home/pi/templog/$1";
else
  file=$(date +"/home/pi/templog/%Y/%m/%d")
fi
maxmin=/home/pi/templog/maxmin
awk '
  {for (f=3; f <=NF; ++f) {
    n=split($f, A, ":");
    if (n!=2) {
        print "badfields",NR,$f,$0 > "/dev/stderr";
        continue;
        }
    dev=A[1];
    temp=A[2];
    if (temp==0) {
        print "temp zero "$f, NR > "/dev/stderr";
        continue;
        }
    sumt[dev] += temp; countt[dev] += 1;
    if (maxt[dev]=="" || maxt[dev] < temp) maxt[dev]=temp;
    if (dev in mint == 0 || mint[dev] > temp) {
      mint[dev]=temp;
      }
    }
   }
  END {
    f=FILENAME;
    gsub(".*log/", "", f);
    printf(f);
    for ( a in maxt) {
      printf(" %s:%.2f:%.2f:%.2f",
             a, mint[a], sumt[a]/countt[a], maxt[a]);
      } printf("\n");
    } ' $file >> ${maxmin}