unitproc/bkt-sum_float

   1 #!/bin/bash
   2 # Desc: Sums newline-delimited floats received from stdin
   3 # Usage: some_app | sumFloat
   4 # Example: printf -- "-3\n0.14" | sumFloat
   5 #   Result: -2.860000
   6 # Version: 0.0.1
   7 # Depends: bc 1.07.1
   8
   9 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  10 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
  11 must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  12 sum_float() {
  13     # Check dependencies
  14     if ! command -v bc 1>/dev/random 2>&1; then die "FATAL:Missing:bc"; fi;
  15
  16     # Store stdin
  17     if [[ -p /dev/stdin ]]; then
  18         input_stdin="$(cat -)" || {
  19             die "FATAL:Error reading stdin."; };
  20     else
  21         die "FATAL:No stdin detected.";
  22     fi;
  23
  24     # Process lines
  25     local sum="0.0";
  26     local re;
  27     re='^[+-]?([0-9]+([.][0-9]*)?|[.][0-9]+)$';
  28     if [[ -n $input_stdin ]]; then
  29         while read -r line; do
  30             if ! [[ "$line" =~ $re ]]; then die "FATAL:Not a float:${line}"; fi;
  31             sum="$(printf -- "%f + %f\n" "$sum" "$line" | bc -l;)";
  32         done < <(printf "%s\n" "$input_stdin") || {
  33             die "FATAL:Error parsing stdin."; };
  34     fi;
  35
  36     # Print result
  37     printf "%f\n" "$sum";
  38 }; # sum stdin floats
  39
  40 # Author: Steven Baltakatei Sandoval
  41 # License: GPLv3+