user-tools/pipeby

   1 #!/bin/bash
   2
   3 true <<'EOF'
   4 =pod
   5
   6 =head1 NAME
   7
   8 pipeby - Run a command and pipe its output to an other one
   9
  10 =head1 SYNOPSIS
  11
  12 pipeby I<CMD_2> [I<ARGS> --] I<CMD_1> [I<ARGS>]
  13
  14 =head1 DESCRIPTION
  15
  16 Equivalent to this shell command:
  17
  18  CMD_1 | CMD_2
  19
  20 =head1 RATIONALE
  21
  22 It is simetimes more convenient to skip shell involvement.
  23
  24 =head1 SEE ALSO
  25
  26 pipexec(1)
  27
  28 =cut
  29
  30 EOF
  31
  32
  33 set -e
  34 set -o pipefail
  35 set -u
  36
  37 if [ $# = 0 ]
  38 then
  39         pod2text "$0" >&2
  40         exit 1
  41 fi
  42 if [ "$1" = --help ]
  43 then
  44         pod2text "$0"
  45         exit 0
  46 fi
  47
  48 declare -a cmd_1=()
  49 declare -a cmd_2=()
  50
  51 cmd_2+=("$1")
  52 shift
  53
  54 while [ $# != 0 ]
  55 do
  56         case "$1" in
  57         --)
  58                 shift
  59                 cmd_2+=("${cmd_1[@]}")
  60                 cmd_1=()
  61                 break
  62                 ;;
  63         *)
  64                 cmd_1+=("$1")
  65                 ;;
  66         esac
  67         shift
  68 done
  69
  70 cmd_1+=("$@")
  71
  72 "${cmd_1[@]}" | "${cmd_2[@]}"