unitproc/bkt-read_stdin_psarg

   1 #!/usr/bin/env bash
   2 # Desc: Reads stdin and positional arguments
   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 $*"; } # runs args as command, reports args if command fails
   7 read_stdin_psarg() {
   8     # Desc: Consumes stdin and reads arguments; outputs as stdout lines
   9     # Input: stdin (consumes)
  10     # Input: args
  11     # Output: stdout (newline delimited)
  12     # Example: read_stdin_psarg "$@"
  13     # Depends: GNU bash (version 5.1.16)
  14     # Version: 0.0.3
  15     local input_stdin input_psarg output;
  16
  17     # Store stdin
  18     if [[ -p /dev/stdin ]]; then
  19         input_stdin="$(cat -)";
  20     fi;
  21
  22     # Store arguments
  23     if [[ $# -gt 0 ]]; then
  24         input_psarg="$*";
  25     fi;
  26
  27     # Combine 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     fi;
  34     ## Read in positional arguments
  35     if [[ -n $input_psarg ]]; then
  36         for arg in "$@"; do
  37             output+=("$arg");
  38         done;
  39     fi;
  40
  41     # Print to stdout
  42     printf "%s\n" "${output[@]}";
  43 }; # read stdin and positional argument to stdout lines
  44 main() {
  45     read_stdin_psarg "$@";
  46 };
  47
  48 main "$@";