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: 0.0.2
   7 # Depends: bc 1.07.1
   8
   9 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  10 dief() { yell "$*"; return 111; } # same as yell() but non-zero return status
  11 must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  12 sum_float() {
  13     # Desc: Sums newline-delimited floats received on stdin
  14     # Usage: some_app | sum_float
  15     # Depends: bc 1.07.1, paste (GNU coreutils)
  16
  17     # Check dependencies
  18     command -v bc 1>/dev/random 2>&1 || { dief "FATAL:Missing:bc"; };
  19     [[ ! -t 0 ]] || { dief "FATAL:No stdin detected."; };
  20
  21     # Process lines
  22     local line re; local -a nums=();
  23     re='^[+-]?([0-9]+([.][0-9]*)?|[.][0-9]+)$';
  24     while IFS= read -r line; do
  25         [[ -z $line ]] && continue;
  26         [[ $line =~ $re ]] || { dief "FATAL:Not a float:${line}"; };
  27         nums+=("$line");
  28     done;
  29
  30     # Print output
  31     if (( ${#nums[@]} == 0 )); then printf '0.000000\n'; return 0; fi;
  32     LC_ALL=C printf '%.6f\n' "$(printf '%s\n' "${nums[@]}" | paste -sd+ - | bc -l)";
  33 } # sum stdin floats
  34
  35 # Author: Steven Baltakatei Sandoval
  36 # License: GPLv3+