Max-E/concalc_wrap.sh

## concalc_wrap.sh
#! /usr/bin/env bash

# DESCRIPTION

# concalc_wrap.sh - Turns Rainer Strobel's batch-mode concalc(1) utility into
# a useful interactive scientific and programming calculator.

# The script is also its own documentation.

# LICENSE

# Copyright (c) 2013 Max Eliaser
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and/or associated documentation files (the
# "Materials"), to deal in the Materials without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Materials, and to
# permit persons to whom the Materials are furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Materials.
#
# THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.

# INTRODUCTION

# I've been a loyal gcalctool user for many years now, even to the point of
# manually installing obsolete versions in order to keep the scientific mode.
# But recently I came to the conclusion that having a buttons for each number
# is completely stupid when I'm going to use the keyboard anyway, and that
# there's no reason I shouldn't get a multi-line display and command history.

# I set out looking for another calculator app that would allow me to use
# pretty much the same keystrokes and features I'd gotten used to from
# gcalctool, while taking up much less screen space and showing multiple lines
# and command history. bc was close, but wouldn't automatically remember
# previous answers and had some other minor differences I didn't want to get
# used to. I briefly considered forking gcalctool before I came to my senses.

# Finally, I found concalc, which was *almost* what I needed. And all its
# shortcomings were easily addressed with a little bit of shell-script
# plumbing.

# FEATURES

# * Permanently stored command line history and command line editing, provided
#   by rlwrap(1)
# * Permanent storage for concalc's settings (mode, base, angle, complex,
#   etc.)
# * Commands to set those settings
# * Automatically prepends "ans" if the first operand of a binary operator is
#   missing (NOTE: use parentheses or a space at the beginning to input a
#   literal -3 instead of ans-3)
# * Automatically juggles concalc's variables file so that multiple instances
#   of this script may be run at once without interfering with each other; the
#   last to exit will have its command history, variables, and settings stored
#   permanently
# * Additional commands for features not provided by Concalc itself (currently
#   just "factor.")
# * Commands for running a single line in a different number system (for
#   example, "hexrun F+F" will always display 1E as a result, regardless of
#   current mode.)
# * Commands for inputting a single line in a different number system (for
#   example, "hexin A+3" will display 13 as a result when in decimal mode.)
# * Commands for displaying the result of a single line in a different number
#   system (for example, "hexout 5+5" will display A when in decimal mode.)
# * User-friendly customization system (by editing this script)

# OTHER NOTES

# I recommend you create an XDG launcher (i.e. a .desktop file) for this
# script using whatever utility your desktop environment provides, and have it
# launch in a graphical terminal emulator window. No need to invoke it
# manually in a shell.

# DEPENDENCIES

# * GNU BASH
# * rlwrap(1)
# * concalc(1)
# * factor(1)
# * fold(1)
# * seq(1)
# * terminal emulator

# CHANGELOG

# * 1.00 - 04/02/13, 9:35 PM GMT-8  - Initial version
# * 1.01 - 04/02/13, 9:45 PM GMT-8  - Fix some comments
# * 1.02 - 04/06/13, 1:54 PM GMT-8  - Add a "factor" command
# * 1.03 - 04/06/13, 3:18 PM GMT-8  - Added "showargs" command to show current
#                                     mode.
#                                   - Unbreak angle setting.
# * 1.04 - 04/06/13, 3:35 PM GMT-8  - Have this script invoke itself, one
#                                     process for rlwrap and one for
#                                     everything else. I think that'll fix all
#                                     these timing issues.
#                                   - Retroactively rewrite the changelog to
#                                     get rid of all the failed past fixes,
#                                     since none of them are in the code now.
# * 1.05 - 04/07/13, 1:16 PM GMT-8  - Add binrun octrun, decrun, and hexrun.
#                                   - Add binin, octin, decin, and hexin.
#                                   - Add binout, octout, decout, and hexout.
#                                   - Validate user input
#                                   - Cleanup code and comments.


# CUSTOMIZABLE CONSTANTS

# Window size in characters
CALC_COLUMNS=30
CALC_LINES=10

# These two lines might mess things up if not run in a graphical terminal
# emulator. You should comment them out entirely if you intend to run them in
# a non-resizable terminal (such as a text-mode VT.)
resize -s $CALC_LINES $CALC_COLUMNS 2>/dev/null 1>/dev/null # Set window size
echo -n $'\e'"]0;calculator"$'\a' # Set tindow title

# Text output gets piped through this
TEXT_FORMAT_CMD="fold -s -w $CALC_COLUMNS"

# Files used by this script
histfile=~/.concalc_wrap_history # Command history
cfgfile=~/.concalc_wrap_config # Configuration

# If the user inputs a command that starts with one of these characters, add
# ans before it
BINARY_OPERATORS='-+*/^%&|'

# This sed script is applied to every command before it is passed to concalc.
# It substitutes "ans" as the first argument if there is a binary operator
# with no first argument specified
SEDSCRIPT='s/^['$BINARY_OPERATORS']/ans&/'


# END customizable constants


#Settings -- they correspond to concalc's command line options
OUTPUT="18"
OUTPUT_VALID_VALS="`seq 1 18`"
MODE="std"
MODE_VALID_VALS="std base"
BASE="dec"
BASE_VALID_VALS="bin oct dec hex"
ANGLE="rad"
ANGLE_VALID_VALS="deg rad gra"
COMPLEX="off"
COMPLEX_VALID_VALS="off on"

# This is where concalc keeps its variables. Don't change this.
varfile=~/.concalcvariables

# This is the line number in $varfile where concalc keeps the "ans" variable
CONCALC_ANS_LINE=53

# This script invokes itself, creating two processes, which is how rlwrap
# likes to work. If you pipe rlwrap's output through another filter, that
# seems to confuse it and lines come out in the wrong order. Also, give rlwrap
# a bit longer than default before it tries to output a prompt.
if [ "x$1" = "x" ] ; then
    exec rlwrap -w 100 rlwrap -S "> " -H $histfile $0 innerloop
fi


# "INNER" PROCESS

# Create temporary files
tmpvarfile=`mktemp`
tmpcfgfile=`mktemp`

# Would be cleaner to write the cfg file directly in the trap without using a
# temporary file, but that doesn't seem to work. Despite every reference I've
# found suggesting that as long as I avoid quotes, the trap command should
# pick up on changed global variables, it doesn't actually seem to do so.
ARGS=""
function gen_concalc_args {
    # write to the temporary config file
    echo output $OUTPUT > $tmpcfgfile
    echo mode $MODE >> $tmpcfgfile
    echo base $BASE >> $tmpcfgfile
    echo angle $ANGLE >> $tmpcfgfile
    echo complex $COMPLEX >> $tmpcfgfile
    # build concalc's arguments
    ARGS="-m $MODE -o $OUTPUT -a $ANGLE"
    if [ "$MODE" = "base" ] ; then
        ARGS=$ARGS" -b $BASE"
    fi
    if [ "$complex" = "on" ] ; then
        ARGS=$ARGS" -c"
    fi
}

# Run a command temporarily in another number system
function tmp_base_cmd {
    old_mode=$MODE
    old_base=$BASE
    MODE=base
    BASE=$1
    gen_concalc_args
    eval "$2"
    BASE=$old_base
    MODE=$old_mode
    gen_concalc_args
}

# For validating whether a setting can be set to a certain value.
function validate_setting {
    new_value=$1
    valid_values="$2"
    found_value=`echo $valid_values | grep -w $new_value`
    if [ "$found_value" ] ; then
        return 0
    fi
    return 1
}

# For controlling one of concalc's settings.
function set_concalc_setting {
    setting_name=$1
    setting_var_name=`echo $1 | tr [a-z] [A-Z]`
    setting_cur_val=`eval "echo $"$setting_var_name`
    setting_valid_vals="`eval "echo $"$setting_var_name"_VALID_VALS"`"
    if [ "x$2" = "x" ] ; then
        echo "Current $setting_name is $setting_cur_val" | $TEXT_FORMAT_CMD
    elif validate_setting $2 "$setting_valid_vals" ; then
        eval "$setting_var_name=$2"
        gen_concalc_args
    else
        valid_vals_fmt="`echo $setting_valid_vals | sed "s/ /, /g"`"
        echo "Invalid $setting_name $2! Valid values are: $valid_vals_fmt." |
            $TEXT_FORMAT_CMD
        echo "Current $setting_name is $setting_cur_val" | $TEXT_FORMAT_CMD
    fi
}

# In addition to running concalc commands, this adds a few extra commands to
# control settings.
function run_command {

    case "x$1" in

        xoutput | xmode | xbase | xangle | xcomplex)
            set_concalc_setting $@
        ;;

        xshowargs)
            echo $ARGS
        ;;

        xbinrun | xoctrun | xdecrun | xhexrun )
            # Run the specified command temporarily in another number system
            tmp_base=`echo $1 | sed "s/run$//"`
            shift
            tmp_base_cmd $tmp_base "run_command $@"
        ;;

        xbinin | xoctin | xdecin | xhexin )
            # Run a command temporarily in another number system, but display
            # its result in the currently selected number system
            tmp_base=`echo $1 | sed "s/in$//"`
            shift
            tmp_base_cmd $tmp_base "run_command $@ 2>/dev/null >/dev/null"
            run_command
        ;;

        xbinout | xoctout | xdecout | xhexout )
            # Run a command in the currently selected number system, but
            # display its result another number system
            tmp_base=`echo $1 | sed "s/out$//"`
            shift
            run_command $@ 2>/dev/null >/dev/null
            tmp_base_cmd $tmp_base "run_command"
        ;;

        xfactor)
            # not provided by concalc but still handy
            if [ "$2" = "ans" ] ; then
                factor `sed -n "$CONCALC_ANS_LINE"p $varfile`
            elif [ "x$2" = "x" ] ; then
                factor `sed -n "$CONCALC_ANS_LINE"p $varfile`
            else
                factor $2
            fi
        ;;

        x)
            concalc $ARGS ans
        ;;

        *)
            concalc $ARGS "$@"
        ;;

    esac

}

# runs all commands piped to it
function loop {
    while read -r line; do
        cp $tmpvarfile $varfile #in case another instance is running
        run_command $line
        cp $varfile $tmpvarfile #save any changes that might have occurred
    done
}

# saves the variable file and config file; the history file is saved already
# by rlwrap
function cleanup {
    mv $tmpvarfile $varfile
    mv $tmpcfgfile $cfgfile
}
trap cleanup EXIT INT TERM


touch $varfile #in case concalc has never been run before
cp $varfile $tmpvarfile #save copy of concalc's variable file

touch $cfgfile #in case this script has never been run before

loop < $cfgfile  # read commands from the config file

gen_concalc_args # generate initial arguments string for concalc

sed -u "$SEDSCRIPT" | loop # read commands from stdin
	#! /usr/bin/env bash

	# DESCRIPTION

	# concalc_wrap.sh - Turns Rainer Strobel's batch-mode concalc(1) utility into
	# a useful interactive scientific and programming calculator.

	# The script is also its own documentation.

	# LICENSE

	# Copyright (c) 2013 Max Eliaser
	#
	# Permission is hereby granted, free of charge, to any person obtaining a
	# copy of this software and/or associated documentation files (the
	# "Materials"), to deal in the Materials without restriction, including
	# without limitation the rights to use, copy, modify, merge, publish,
	# distribute, sublicense, and/or sell copies of the Materials, and to
	# permit persons to whom the Materials are furnished to do so, subject to
	# the following conditions:
	#
	# The above copyright notice and this permission notice shall be included
	# in all copies or substantial portions of the Materials.
	#
	# THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
	# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
	# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	# MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.

	# INTRODUCTION

	# I've been a loyal gcalctool user for many years now, even to the point of
	# manually installing obsolete versions in order to keep the scientific mode.
	# But recently I came to the conclusion that having a buttons for each number
	# is completely stupid when I'm going to use the keyboard anyway, and that
	# there's no reason I shouldn't get a multi-line display and command history.

	# I set out looking for another calculator app that would allow me to use
	# pretty much the same keystrokes and features I'd gotten used to from
	# gcalctool, while taking up much less screen space and showing multiple lines
	# and command history. bc was close, but wouldn't automatically remember
	# previous answers and had some other minor differences I didn't want to get
	# used to. I briefly considered forking gcalctool before I came to my senses.

	# Finally, I found concalc, which was almost what I needed. And all its
	# shortcomings were easily addressed with a little bit of shell-script
	# plumbing.

	# FEATURES

	# * Permanently stored command line history and command line editing, provided
	# by rlwrap(1)
	# * Permanent storage for concalc's settings (mode, base, angle, complex,
	# etc.)
	# * Commands to set those settings
	# * Automatically prepends "ans" if the first operand of a binary operator is
	# missing (NOTE: use parentheses or a space at the beginning to input a
	# literal -3 instead of ans-3)
	# * Automatically juggles concalc's variables file so that multiple instances
	# of this script may be run at once without interfering with each other; the
	# last to exit will have its command history, variables, and settings stored
	# permanently
	# * Additional commands for features not provided by Concalc itself (currently
	# just "factor.")
	# * Commands for running a single line in a different number system (for
	# example, "hexrun F+F" will always display 1E as a result, regardless of
	# current mode.)
	# * Commands for inputting a single line in a different number system (for
	# example, "hexin A+3" will display 13 as a result when in decimal mode.)
	# * Commands for displaying the result of a single line in a different number
	# system (for example, "hexout 5+5" will display A when in decimal mode.)
	# * User-friendly customization system (by editing this script)

	# OTHER NOTES

	# I recommend you create an XDG launcher (i.e. a .desktop file) for this
	# script using whatever utility your desktop environment provides, and have it
	# launch in a graphical terminal emulator window. No need to invoke it
	# manually in a shell.

	# DEPENDENCIES

	# * GNU BASH
	# * rlwrap(1)
	# * concalc(1)
	# * factor(1)
	# * fold(1)
	# * seq(1)
	# * terminal emulator

	# CHANGELOG

	# * 1.00 - 04/02/13, 9:35 PM GMT-8 - Initial version
	# * 1.01 - 04/02/13, 9:45 PM GMT-8 - Fix some comments
	# * 1.02 - 04/06/13, 1:54 PM GMT-8 - Add a "factor" command
	# * 1.03 - 04/06/13, 3:18 PM GMT-8 - Added "showargs" command to show current
	# mode.
	# - Unbreak angle setting.
	# * 1.04 - 04/06/13, 3:35 PM GMT-8 - Have this script invoke itself, one
	# process for rlwrap and one for
	# everything else. I think that'll fix all
	# these timing issues.
	# - Retroactively rewrite the changelog to
	# get rid of all the failed past fixes,
	# since none of them are in the code now.
	# * 1.05 - 04/07/13, 1:16 PM GMT-8 - Add binrun octrun, decrun, and hexrun.
	# - Add binin, octin, decin, and hexin.
	# - Add binout, octout, decout, and hexout.
	# - Validate user input
	# - Cleanup code and comments.


	# CUSTOMIZABLE CONSTANTS

	# Window size in characters
	CALC_COLUMNS=30
	CALC_LINES=10

	# These two lines might mess things up if not run in a graphical terminal
	# emulator. You should comment them out entirely if you intend to run them in
	# a non-resizable terminal (such as a text-mode VT.)
	resize -s $CALC_LINES $CALC_COLUMNS 2>/dev/null 1>/dev/null # Set window size
	echo -n $'\e'"]0;calculator"$'\a' # Set tindow title

	# Text output gets piped through this
	TEXT_FORMAT_CMD="fold -s -w $CALC_COLUMNS"

	# Files used by this script
	histfile=~/.concalc_wrap_history # Command history
	cfgfile=~/.concalc_wrap_config # Configuration

	# If the user inputs a command that starts with one of these characters, add
	# ans before it
	BINARY_OPERATORS='-+*/^%&\|'

	# This sed script is applied to every command before it is passed to concalc.
	# It substitutes "ans" as the first argument if there is a binary operator
	# with no first argument specified
	SEDSCRIPT='s/^['$BINARY_OPERATORS']/ans&/'


	# END customizable constants


	#Settings -- they correspond to concalc's command line options
	OUTPUT="18"
	OUTPUT_VALID_VALS="`seq 1 18`"
	MODE="std"
	MODE_VALID_VALS="std base"
	BASE="dec"
	BASE_VALID_VALS="bin oct dec hex"
	ANGLE="rad"
	ANGLE_VALID_VALS="deg rad gra"
	COMPLEX="off"
	COMPLEX_VALID_VALS="off on"

	# This is where concalc keeps its variables. Don't change this.
	varfile=~/.concalcvariables

	# This is the line number in $varfile where concalc keeps the "ans" variable
	CONCALC_ANS_LINE=53

	# This script invokes itself, creating two processes, which is how rlwrap
	# likes to work. If you pipe rlwrap's output through another filter, that
	# seems to confuse it and lines come out in the wrong order. Also, give rlwrap
	# a bit longer than default before it tries to output a prompt.
	if [ "x$1" = "x" ] ; then
	exec rlwrap -w 100 rlwrap -S "> " -H $histfile $0 innerloop
	fi


	# "INNER" PROCESS

	# Create temporary files
	tmpvarfile=`mktemp`
	tmpcfgfile=`mktemp`

	# Would be cleaner to write the cfg file directly in the trap without using a
	# temporary file, but that doesn't seem to work. Despite every reference I've
	# found suggesting that as long as I avoid quotes, the trap command should
	# pick up on changed global variables, it doesn't actually seem to do so.
	ARGS=""
	function gen_concalc_args {
	# write to the temporary config file
	echo output $OUTPUT > $tmpcfgfile
	echo mode $MODE >> $tmpcfgfile
	echo base $BASE >> $tmpcfgfile
	echo angle $ANGLE >> $tmpcfgfile
	echo complex $COMPLEX >> $tmpcfgfile
	# build concalc's arguments
	ARGS="-m $MODE -o $OUTPUT -a $ANGLE"
	if [ "$MODE" = "base" ] ; then
	ARGS=$ARGS" -b $BASE"
	fi
	if [ "$complex" = "on" ] ; then
	ARGS=$ARGS" -c"
	fi
	}

	# Run a command temporarily in another number system
	function tmp_base_cmd {
	old_mode=$MODE
	old_base=$BASE
	MODE=base
	BASE=$1
	gen_concalc_args
	eval "$2"
	BASE=$old_base
	MODE=$old_mode
	gen_concalc_args
	}

	# For validating whether a setting can be set to a certain value.
	function validate_setting {
	new_value=$1
	valid_values="$2"
	found_value=`echo $valid_values \| grep -w $new_value`
	if [ "$found_value" ] ; then
	return 0
	fi
	return 1
	}

	# For controlling one of concalc's settings.
	function set_concalc_setting {
	setting_name=$1
	setting_var_name=`echo $1 \| tr [a-z] [A-Z]`
	setting_cur_val=`eval "echo $"$setting_var_name`
	setting_valid_vals="`eval "echo $"$setting_var_name"_VALID_VALS"`"
	if [ "x$2" = "x" ] ; then
	echo "Current $setting_name is $setting_cur_val" \| $TEXT_FORMAT_CMD
	elif validate_setting $2 "$setting_valid_vals" ; then
	eval "$setting_var_name=$2"
	gen_concalc_args
	else
	valid_vals_fmt="`echo $setting_valid_vals \| sed "s/ /, /g"`"
	echo "Invalid $setting_name $2! Valid values are: $valid_vals_fmt." \|
	$TEXT_FORMAT_CMD
	echo "Current $setting_name is $setting_cur_val" \| $TEXT_FORMAT_CMD
	fi
	}

	# In addition to running concalc commands, this adds a few extra commands to
	# control settings.
	function run_command {

	case "x$1" in

	xoutput \| xmode \| xbase \| xangle \| xcomplex)
	set_concalc_setting $@
	;;

	xshowargs)
	echo $ARGS
	;;

	xbinrun \| xoctrun \| xdecrun \| xhexrun )
	# Run the specified command temporarily in another number system
	tmp_base=`echo $1 \| sed "s/run$//"`
	shift
	tmp_base_cmd $tmp_base "run_command $@"
	;;

	xbinin \| xoctin \| xdecin \| xhexin )
	# Run a command temporarily in another number system, but display
	# its result in the currently selected number system
	tmp_base=`echo $1 \| sed "s/in$//"`
	shift
	tmp_base_cmd $tmp_base "run_command $@ 2>/dev/null >/dev/null"
	run_command
	;;

	xbinout \| xoctout \| xdecout \| xhexout )
	# Run a command in the currently selected number system, but
	# display its result another number system
	tmp_base=`echo $1 \| sed "s/out$//"`
	shift
	run_command $@ 2>/dev/null >/dev/null
	tmp_base_cmd $tmp_base "run_command"
	;;

	xfactor)
	# not provided by concalc but still handy
	if [ "$2" = "ans" ] ; then
	factor `sed -n "$CONCALC_ANS_LINE"p $varfile`
	elif [ "x$2" = "x" ] ; then
	factor `sed -n "$CONCALC_ANS_LINE"p $varfile`
	else
	factor $2
	fi
	;;

	x)
	concalc $ARGS ans
	;;

	*)
	concalc $ARGS "$@"
	;;

	esac

	}

	# runs all commands piped to it
	function loop {
	while read -r line; do
	cp $tmpvarfile $varfile #in case another instance is running
	run_command $line
	cp $varfile $tmpvarfile #save any changes that might have occurred
	done
	}

	# saves the variable file and config file; the history file is saved already
	# by rlwrap
	function cleanup {
	mv $tmpvarfile $varfile
	mv $tmpcfgfile $cfgfile
	}
	trap cleanup EXIT INT TERM


	touch $varfile #in case concalc has never been run before
	cp $varfile $tmpvarfile #save copy of concalc's variable file

	touch $cfgfile #in case this script has never been run before

	loop < $cfgfile # read commands from the config file

	gen_concalc_args # generate initial arguments string for concalc

	sed -u "$SEDSCRIPT" \| loop # read commands from stdin