unitproc/bkt-read_stdin

   1 #!/usr/bin/env bash
   2 # Desc: Reads stdin
   3
   4 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
   5 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
   6 must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
   7 read_stdin() {
   8     # Desc: Consumes stdin; outputs as stdout lines
   9     # Input: stdin (consumes)
  10     # Output: stdout  (newline delimited)
  11     #         return  0  stdin read
  12     #         return  1  stdin not present
  13     # Example: printf "foo\nbar\n" | read_stdin
  14     # Depends: GNU bash (version 5.1.16), GNU Coreutils 8.32 (cat)
  15     # Version: 0.1.1
  16     # Attrib: Steven Baltakatei Sandoval (2024-01-29). reboil.com
  17     local input_stdin output;
  18
  19     # Store stdin
  20     if [[ -p /dev/stdin ]]; then
  21         input_stdin="$(cat -)" || {
  22             echo "FATAL:Error reading stdin." 1>&2; return 1; };
  23     else
  24         return 1;
  25     fi;
  26
  27     # Store as output array elements
  28     ## Read in stdin
  29     if [[ -n $input_stdin ]]; then
  30         while read -r line; do
  31             output+=("$line");
  32         done < <(printf "%s\n" "$input_stdin") || {
  33             echo "FATAL:Error parsing stdin."; return 1; };
  34     fi;
  35
  36     # Print to stdout
  37     printf "%s\n" "${output[@]}";
  38
  39     return 0;
  40 }; # read stdin to stdout lines
  41
  42 yell "WARNING:This is a Bash function definition for read_stdin.";