#!/bin/bash
#
# Copyright (C) 2007-2008 Eric Shubert <ejs@shubes.net>
#
########################################################################
#
# script for listing/selecting man pages for a package
#
########################################################################
#
# change log
# 04/04/08 shubes - changed `` to $()
# 02/15/07 shubes - created
#
########################################################################
## if dialog is not installed, offer to install it if yum is available
#
a2_check_dialog(){

which rpm >/dev/null 2>&1

if [ $? != "0" ]; then
  echo "$me only runs on rpm based distros, sorry."
  exit 1
fi

which dialog >/dev/null 2>&1

if [ $? != "0" ]; then
  which yum >/dev/null 2>&1
  if [ $? != "0" ]; then
    echo "dialog is not installed and neither is yum, so I can't install it."
    echo "Please install dialog manually and try again."
    exit 1
  else
    echo -n "dialog is not installed, would you like to install it? [y]|n : "
    read REPLY
    case $REPLY in
      "y" | "yes" | "" )
        sudo yum -y install dialog
        if [ $? != "0" ]; then
          echo "$me - installation of dialog failed, exiting."
          exit 1
        fi
        ;;
      * )
        echo "I can't do my thing without dialog installed, sorry."
        exit 1
        ;;
    esac
  fi
fi
}

########################################################################
## get package names into a sorted list
#
a3_get_package_list(){

if [ ! -z "$sregex" ]; then
  pkgs="$(rpm -qa | grep \"$sregex\")"
fi

for pkg in $pkg $pkgs; do
  echo $pkg >> $tempdial
done
}

########################################################################
## package(s) found, so process the request
#
a5_process_request(){

pkglist=`sort <$tempdial`
captpkgs="Packages: "
items=0

if [ -z "$sect" ]; then
  sectexp="."
else
  sectexp="[$sect]"
fi

for pkg in $pkglist; do
  manfiles=$(rpm -ql $pkg | grep man/man$sectexp/)
  if [ $? == "0" ]; then
    b54_process_each_package
  fi
done

if [ -s $tempmenu ]; then
  b56_show_the_menu
else
  echo "There are no man pages available for $pkglist $msgsect $sect"
fi
}

########################################################################
## build the man pages for the package into the menu list
#
b54_process_each_package(){

if (($W_MENU_HEIGHT > 5 )); then
  W_MENU_HEIGHT=$(($W_MENU_HEIGHT - 1))
  CAPTION="${CAPTION}${captpkgs}${pkg} "
  captpkgs="\n          "
else
  CAPTION="${CAPTION}."
fi

for manfilename in $manfiles; do
  c545_each_package_manpage
done
}

########################################################################
## build a menu entry for the man page
#
c545_each_package_manpage(){

items=$(($items + 1))
manfile=${manfilename##/[^/]*/man/man[$MANSECTS]/}
mantemp=${manfile%.[^.]*}
manname=${mantemp%.[$MANSECTS]}
mansect=${mantemp#$manname.}
found=""

while read whatpage whatsect whatdash whatdesc; do
  whatsect=$(echo $whatsect | tr -d "()")
  if [ "$whatpage" == "$manname" ] \
        && [ "$whatsect" == "$mansect" ]; then
    found=0
    break
  fi
done <<!EOF!
$(whatis $manname)
!EOF!

if [ "$found" ]; then
  echo "\"${whatpage} $whatsect\" \"$whatdesc\"" >>$tempmenu
else
  echo "\"${manname} $mansect\" \"-- No Description Available --\"" >>$tempmenu
fi
}

########################################################################
## there's something to show, so show the menu
#
b56_show_the_menu(){

CAPTION="$CAPTION\n manpage Sec#        Description\n"

if (($items < $W_MENU_HEIGHT )); then
  W_HEIGHT=$(($W_HEIGHT - $W_MENU_HEIGHT + $items ))
  W_MENU_HEIGHT=$items
fi

while true; do
  c565_process_menu
done
}

########################################################################
## invoke the dialog command to display the menu, then check selection
#
c565_process_menu(){

${DIALOG:=dialog} --clear \
      --help-button \
      --help-label Sections \
      --ok-label Man \
      --title "Menu of man pages" \
      --menu "$CAPTION" \
            $W_HEIGHT $W_WIDTH $W_MENU_HEIGHT \
      --file $tempmenu \
      2>$tempdial

case $? in
  0 )
    read manpage section <$tempdial
    man $section $manpage
    ;;
  1 )
#   No or Cancel button was pressed
    break
    ;;
  2 )
#   Help button was pressed, if present
    d5656_show_sections
    ;;
  3 )
#   Extra button was pressed, if present
    break
    ;;
  -1 )
#   errors occured, or exited via the ESC key
    break
    ;;
  * )
#   undefined return code
    break
    ;;
esac
}

########################################################################
## show help screen with section descriptions
#
d5656_show_sections(){

if [ ! -f $temphelp ]; then
  echo "#   Topic" >$temphelp
  echo "1   Commands available to users" >>$temphelp
  echo "2   Unix and C system calls" >>$temphelp
  echo "3   C library routines for C programs" >>$temphelp
  echo "4   Special file names" >>$temphelp
  echo "5   File formats and conventions for Linux" >>$temphelp
  echo "6   Games" >>$temphelp
  echo "7   Word processing packages" >>$temphelp
  echo -n "8   System administration commands, processes" >>$temphelp
fi

$DIALOG --clear  \
      --exit-label Back \
      --title "man Sections" \
      --textbox $temphelp 13 49 \
      2>$tempdial
}

########################################################################
## show usage and exit
#
q01_usage_exit(){

echo "usage: $me [section] ... {-s regex | package_name} [package_name] ..."
exit 1
}

########################################################################
## main execution begins here
#

me=$(basename $0)
myver=v0.3
MANSECTS="1-8"
sect=""
pkg=""
msgnf=""
msgsect=""
CAPTION=""
W_HEIGHT=$((${LINES:-24} - 3))
W_WIDTH=$((${COLUMNS:-80} - 4))
W_MENU_HEIGHT=$(($W_HEIGHT - 7))

if [ -z "$1" ]; then
  q01_usage_exit
else
  while (( "$#" )); do
    case $1 in
      "-h" )
        q01_usage_exit
        ;;
      [$MANSECTS] )
        sect="$sect$1"
        msgsect=" in section(s)"
        shift
        ;;
      "-s" )
        if [ -z "$2" ]; then
          echo "$me - regex parameter not supplied"
          q01_usage_exit
        else
          sregex="$2"
          msgmatch="matching"
          CAPTION="Matching: ${2}\n"
          W_MENU_HEIGHT=$(($W_MENU_HEIGHT - 1))
          shift 2
        fi
        ;;
      * )
        pkgver=`rpm -q $1 2>/dev/null`
        if [ $? == "0" ]; then
          pkg="$pkg $pkgver"
          shift
        else
          echo "Package $1 is not installed"
          exit 1
        fi
        ;;
    esac
  done
fi

a2_check_dialog

# set a temp file for the working scratch, menu and help
tempdial=`tempfile 2>/dev/null` || tempdial=/tmp/$me.dial.$$
tempmenu=`tempfile 2>/dev/null` || tempmenu=/tmp/$me.menu.$$
temphelp=`tempfile 2>/dev/null` || temphelp=/tmp/$me.help.$$

# make sure the temp files are deleted when we're done
trap "rm -f $tempdial $tempmenu $temphelp" 0 1 2 5 15

a3_get_package_list

if [ -s $tempdial ]; then
  a5_process_request
else
  echo "No package(s)$pkg found $msgmatch $sregex"
fi

exit 0