helpmselect

   1 #!/bin/sh
   2 # Copyright © 2014 Géraud Meyer <graud@gmx.com>
   3 #
   4 # This program is free software; you can redistribute it and/or modify it under
   5 # the terms of the GNU General Public License version 2 as published by the
   6 # Free Software Foundation.
   7 #
   8 # This program is distributed in the hope that it will be useful, but WITHOUT
   9 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  10 # FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  11 # details.
  12 #
  13 # You should have received a copy of the GNU General Public License along with
  14 # this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 PROGRAM_NAME="helpmselect"
  17 PROGRAM_VERSION="0.1"
  18 # <<"HelpMessage"
  19 #NAME
  20 #       helpmselect - filter out sections from a HelpMessage
  21 #SYNOPSIS
  22 #       helpmselect [<options>] [--] <format>[-] [<file>]
  23 #HelpMessage
  24
  25 GETOPT_OPT=r:k:HV
  26 GETOPT_LOPT=remove:,keep:,no-header,version
  27 if getopt -T >/dev/null
  28 then CL=`getopt $GETOPT_OPT $*`
  29 else CL=`getopt -o $GETOPT_OPT -l $GETOPT_LOPT -- "$@"`
  30 fi
  31 if [ $? -ne 0 ]
  32 then echo >&2 "$PROGRAM_NAME: syntax error"; exit 255
  33 fi
  34 if getopt -T >/dev/null
  35 then set -- $CL
  36 else eval set -- "$CL"
  37 fi
  38 REMOVE=''; _REMOVE=
  39 KEEP=''
  40 HEADER=1
  41 while [ $# -gt 0 ]
  42 do
  43         case $1 in
  44         -V|--version) echo "$PROGRAM_NAME version $PROGRAM_VERSION"; exit ;;
  45         -r|--remove) shift; REMOVE="$REMOVE${_REMOVE:+ }$1"; _REMOVE=set ;;
  46         -k|--keep) shift; KEEP="$KEEP$1" ;;
  47         -H|--no-header) HEADER=0 ;;
  48         --) shift; break ;;
  49         *) break ;;
  50         esac
  51         shift
  52 done
  53 [ -z "$_REMOVE" ] && REMOVE='^$'
  54 if [ $# -gt 1 ]
  55 then echo >&2 "$PROGRAM_NAME: error: too many arguments"; exit 255
  56 fi
  57 if [ $# -gt 0 ] && expr "$1" : '[a-zA-Z_][a-zA-Z_0-9]*=' >/dev/null
  58 then set -- ./"$1"
  59 fi
  60
  61 awk -v KEEP="$KEEP" -v REMOVE="$REMOVE" '
  62 BEGIN {
  63         keep = '$HEADER' # keep or not the header
  64 }
  65 # section title
  66 /^([^ \t#\/]|\/[^\/])/ {
  67         if ($0 ~ KEEP) keep = 1
  68         else keep = 0
  69         if ($0 ~ REMOVE) keep = 0
  70 }
  71 # keep
  72 keep {
  73         print
  74 }' "${1--}"
  75
  76 # <<"HelpMessage"
  77 #DESCRIPTION
  78 #       helpmselect removes some sections from a HelpMessage read from <file> or
  79 #       from the standard input.  By default all the sections are kept, and none
  80 #       are removed.
  81 #
  82 #       If a section matches the ERE (awk Extended Regular Expression) given to
  83 #       --remove, it is removed.  Otherwise if it does not match the ERE given to
  84 #       --keep, it is removed.  The remaining sections are kept in the standard
  85 #       output.  If several identical options are found, the value used is the
  86 #       concatenation of the options separated by spaces.
  87 #
  88 #       If --no-header is given, anything that comes before the first section is
  89 #       removed.
  90 #OPTIONS
  91 #       The options are parsed by getopt(1).
  92 #       -k, --keep <regex>
  93 #       -r, --remove <regex>
  94 #       -H, --no-header
  95 #EXIT STATUS
  96 #       A non zero exit status would indicate an error for awk itself.
  97 #EXAMPLES
  98 #       In a shell script, make a usage message from the embedded HelpMessage:
  99 #         $ helpm4sh $0 2>/dev/null |
 100 #           helpmselect --no-header --keep 'SYNOPSIS|OPTIONS' |
 101 #           helpm2text
 102 #AUTHOR
 103 #       helpmselect was written by G.raud Meyer.
 104 #SEE ALSO
 105 #       helpmessage(5), helpm2pod(1), helpm2text(1)
 106 #HelpMessage