#!/bin/sh
##
## SCRIPT: xpg
##
##############################################################################
## PURPOSE: This shell script starts up a GUI utility, nicknamed 'xpg', to
##          browse AND/OR search AND/OR extract-match-lines AND/OR
##          print a text file.
##
##############################################################################
## FURTHER DESCRIPTION:
##          This script calls Tcl-Tk script 'shofil.tk' to present the GUI
##          and to do browse actions on the text file --- per user actions on
##          the widgets of the GUI.
##
##          By default, this script starts 'shofil.tk' in the BACKGROUND.
##          (Uses an '&' with 'shofil.tk' for BACKGROUND execution.)
##          But the user can supply a '-f' parameter to this script, to
##          force FOREGROUND execution of 'shofil.tk'.
##
## 'shofil.tk' is basically an X-GUI-version of the Unix (SGI-IRIX)
## 'pg' command. The 'pg' command offered a way to 'page' back and forth
## through a text file in a Unix virtual terminal. The 'pg' command
## was similar to the 'more' and 'less' command --- a big step up from
## using the 'cat' command to browse a text file. 'cat' did not have an
## option to page back (or forward) in the text.
##
## 'shofil.tk' adds a unique extract-matching-lines facility as well as
## built-in print function --- in addition to browse & search functions
## similar to those of the non-GUI 'pg' command (which is like 'less')
## --- but the 'xpg/'shofil.tk' browse & search options are much nicer
## (easier to use, faster, feature-rich).
##############################################################################
## CALLED BY:  Can be called  manually at a Unix shell prompt.
##             Example:   xpg <text-filename>
##
## Also could be called from within shell or Tcl-Tk scripts.
##
## One of many ways the 'xpg' script could be implemented on Linux/Unix/BSD:
##
##     Each user could implement 'xpg' via a shortname alias
##     put in their $HOME/.bashrc or $HOME/.bash_aliases
##     or $HOME/.kshrc or $HOME/.profile (or whatever) file, like
##
##         alias xpg='$DIRxpg/scripts/xpg'
##
##     where $DIRxpg represents the install directory of the 'xpg'
##     system files:
##        Tk scripts:
##                    shofil.tk
##                    sho_colorvals_via_sliders3rgb.tk
##                    select_font.tk
##     Shell scripts:
##                    xpg
##                    findANDshow_NOTstringsINfile.sh
##                    findANDshow_stringsINfile_plusminusNlines.sh
##                    set_localoutlist.sh
##         Help file:
##                    shofil.hlp  (plain text)
##
##     The directory DIRxpg could be a subdirectory of the user's
##     home directory --- example:
##          $HOME/apps/xpg
##
##     Alternatively, a link to that 'xpg' script could be used.
##     Example: $HOME/apps/bin/xpg
##############################################################################
## This 'xpg' script was adapted from the 'xpg' script of the 'FE xpg'
## subsystem, which is provided, along with other FE subsystems, at
## www.freedomenv.com.  FE = Freedom Environment
## FE system Copyright 2006+ by Blaise Montandon
##############################################################################
## MAINTENANCE HISTORY of this 'xpg' script for posting at wiki.tcl.tk:
##
## Written by: Blaise Montandon 2013aug05 Started based on the 'xpg' script
##                                        of the 'FE xpg' subsystem which is
##                                        packaged at www.freedomenv.com.
## Updated by: Blaise Montandon 20.......
##############################################################################

#############################################################
## Set the installation directory of the set of 'xpg' files.
#############################################################

# DIRxpg="$HOME/apps/xpg"
  DIRxpg="."


######################
## Set USAGE_TEXT var.
######################

SCRIPTBASENAME=`basename $0`

USAGE_TEXT="Usage:  $SCRIPTBASENAME  [-h] [-f] file1 [ file2 ... file8 ]
-h - gives this help
-f - to execute this utility in the foreground, rather than background."


###########################################################
## If this script was not executed on the command line and
## if no vars (filenames) were passed, pop a msg (using
## the 'zenity' utility) and exit.
###########################################################

## FOR TESTING:
#  env > $HOME/env.lis

if test "$_" = "" -a "$1" = ""
then
   zenity --info --title "xpg: Need filename." \
      --text "\
No filename was passed to the 'xpg' script.

$USAGE_TEXT

Exiting."
    exit
fi

####################################################################
## Otherwise, if this script IS executed on the command line
## and if no vars (esp. filenames) were passed, echo a msg and exit.
####################################################################

# if test $# -eq 0
if test "$1" = ""
then
   echo "
$USAGE_TEXT
"
   exit
fi


##############################################################################
## Process 'xpg' command options with 'getopts'.
##############################################################################
## '-q' (for QUIET) is not used for now. Maybe someday.
##############################################################################

QUIET=false
FOREGROUND=false
while getopts qhf OPTION
do
   ## FOR TESTING
   # echo "OPTION: $OPTION"

   case $OPTION in
   q)
      QUIET=true
      ;;

   f)
      FOREGROUND=true
      ;;


    h|?)
      echo "
$USAGE_TEXT
"
      exit
      ;;

   esac
done
shift `expr $OPTIND - 1`


##############################################################################
## STARTUP THE 'xpg' GUI --- using a loop.
## A max of 8 files is accepted --- to prevent
## starting up a huge bunch of instances. Who hasn't done that?
##############################################################################
## NOTE: We are using a 'for' loop --- WITHOUT 'in' --- to handle getting
##       filenames --- even filenames with embedded spaces. Ref: man bash
##############################################################################

## FOR TESTING:
#   set -x


#########################################################
## These vars can be changed to set the initial location
## and size of the shofil.tk window(s).
##   USERS MIGHT WANT TO RESET THESE TO SUIT THEIR OWN
##   PREFERENCES.
#########################################################

# export WINLOCX="80"
# export WINLOCY="80"
# export WINSIZEX="750"
# export WINSIZEY="450"


#############################################################
## CNT is used in the loop below to delay starting subsquent
## instances of shofil.tk.
## CNT is also used to limit input filenames to 8.
#############################################################

CNT=0

###############################################################
## The LOOP to display the files, with shofil.tk, for the
## filenames passed to this 'xpg' script. (max of 8 files used)
###############################################################

for FILE
do

   ## FOR TESTING:
   # echo "
   # FILE = $FILE"

   if test $CNT = 0
   then
      CNT=`expr $CNT + 1`
   else
      ## Pause before starting subsequent instances,
      ## to make sure they are noticed.
      sleep 1
      CNT=`expr $CNT + 1`
   fi


   ## FOR TESTING:
   # set -x

   if test "$FOREGROUND" = "false"
   then
      $DIRxpg/shofil.tk "$FILE" &
   else
      $DIRxpg/shofil.tk "$FILE"
   fi

   ## FOR TESTING:
   # set -

   if test $CNT -ge 8
   then
      exit
   fi

done