36.5. "Colorizing" Scripts

#!/bin/bash
# ex30a.sh: "Colorized" version of ex30.sh.
#            Crude address database


clear                                   # Clear the screen.

echo -n "          "
echo -e '\E[37;44m'"\033[1mContact List\033[0m"
                                        # White on blue background
echo; echo
echo -e "\033[1mChoose one of the following persons:\033[0m"
                                        # Bold
tput sgr0                               # Reset attributes.
echo "(Enter only the first letter of name.)"
echo
echo -en '\E[47;34m'"\033[1mE\033[0m"   # Blue
tput sgr0                               # Reset colors to "normal."
echo "vans, Roland"                     # "[E]vans, Roland"
echo -en '\E[47;35m'"\033[1mJ\033[0m"   # Magenta
tput sgr0
echo "ambalaya, Mildred"
echo -en '\E[47;32m'"\033[1mS\033[0m"   # Green
tput sgr0
echo "mith, Julie"
echo -en '\E[47;31m'"\033[1mZ\033[0m"   # Red
tput sgr0
echo "ane, Morris"
echo

read person

case "$person" in
# Note variable is quoted.

  "E" | "e" )
  # Accept upper or lowercase input.
  echo
  echo "Roland Evans"
  echo "4321 Flash Dr."
  echo "Hardscrabble, CO 80753"
  echo "(303) 734-9874"
  echo "(303) 734-9892 fax"
  echo "revans@zzy.net"
  echo "Business partner & old friend"
  ;;

  "J" | "j" )
  echo
  echo "Mildred Jambalaya"
  echo "249 E. 7th St., Apt. 19"
  echo "New York, NY 10009"
  echo "(212) 533-2814"
  echo "(212) 533-9972 fax"
  echo "milliej@loisaida.com"
  echo "Girlfriend"
  echo "Birthday: Feb. 11"
  ;;

# Add info for Smith & Zane later.

          * )
   # Default option.	  
   # Empty input (hitting RETURN) fits here, too.
   echo
   echo "Not yet in database."
  ;;

esac

tput sgr0                               # Reset colors to "normal."

echo

exit 0

#!/bin/bash
# Draw-box.sh: Drawing a box using ASCII characters.

# Script by Stefano Palmeri, with minor editing by document author.
# Minor edits suggested by Jim Angstadt.
# Used in the ABS Guide with permission.


######################################################################
###  draw_box function doc  ###

#  The "draw_box" function lets the user
#+ draw a box in a terminal.       
#
#  Usage: draw_box ROW COLUMN HEIGHT WIDTH [COLOR] 
#  ROW and COLUMN represent the position        
#+ of the upper left angle of the box you're going to draw.
#  ROW and COLUMN must be greater than 0
#+ and less than current terminal dimension.
#  HEIGHT is the number of rows of the box, and must be > 0. 
#  HEIGHT + ROW must be <= than current terminal height. 
#  WIDTH is the number of columns of the box and must be > 0.
#  WIDTH + COLUMN must be <= than current terminal width.
#
# E.g.: If your terminal dimension is 20x80,
#  draw_box 2 3 10 45 is good
#  draw_box 2 3 19 45 has bad HEIGHT value (19+2 > 20)
#  draw_box 2 3 18 78 has bad WIDTH value (78+3 > 80)
#
#  COLOR is the color of the box frame.
#  This is the 5th argument and is optional.
#  0=black 1=red 2=green 3=tan 4=blue 5=purple 6=cyan 7=white.
#  If you pass the function bad arguments,
#+ it will just exit with code 65,
#+ and no messages will be printed on stderr.
#
#  Clear the terminal before you start to draw a box.
#  The clear command is not contained within the function.
#  This allows the user to draw multiple boxes, even overlapping ones.

###  end of draw_box function doc  ### 
######################################################################

draw_box(){

#=============#
HORZ="-"
VERT="|"
CORNER_CHAR="+"

MINARGS=4
E_BADARGS=65
#=============#


if [ $# -lt "$MINARGS" ]; then          # If args are less than 4, exit.
    exit $E_BADARGS
fi

# Looking for non digit chars in arguments.
# Probably it could be done better (exercise for the reader?).
if echo $@ | tr -d [:blank:] | tr -d [:digit:] | grep . &> /dev/null; then
   exit $E_BADARGS
fi

BOX_HEIGHT=`expr $3 - 1`   #  -1 correction needed because angle char "+"
BOX_WIDTH=`expr $4 - 1`    #+ is a part of both box height and width.
T_ROWS=`tput lines`        #  Define current terminal dimension 
T_COLS=`tput cols`         #+ in rows and columns.
         
if [ $1 -lt 1 ] || [ $1 -gt $T_ROWS ]; then    #  Start checking if arguments
   exit $E_BADARGS                             #+ are correct.
fi
if [ $2 -lt 1 ] || [ $2 -gt $T_COLS ]; then
   exit $E_BADARGS
fi
if [ `expr $1 + $BOX_HEIGHT + 1` -gt $T_ROWS ]; then
   exit $E_BADARGS
fi
if [ `expr $2 + $BOX_WIDTH + 1` -gt $T_COLS ]; then
   exit $E_BADARGS
fi
if [ $3 -lt 1 ] || [ $4 -lt 1 ]; then
   exit $E_BADARGS
fi                                 # End checking arguments.

plot_char(){                       # Function within a function.
   echo -e "\E[${1};${2}H"$3
}

echo -ne "\E[3${5}m"               # Set box frame color, if defined.

# start drawing the box

count=1                                         #  Draw vertical lines using
for (( r=$1; count<=$BOX_HEIGHT; r++)); do      #+ plot_char function.
  plot_char $r $2 $VERT
  let count=count+1
done 

count=1
c=`expr $2 + $BOX_WIDTH`
for (( r=$1; count<=$BOX_HEIGHT; r++)); do
  plot_char $r $c $VERT
  let count=count+1
done 

count=1                                        #  Draw horizontal lines using
for (( c=$2; count<=$BOX_WIDTH; c++)); do      #+ plot_char function.
  plot_char $1 $c $HORZ
  let count=count+1
done 

count=1
r=`expr $1 + $BOX_HEIGHT`
for (( c=$2; count<=$BOX_WIDTH; c++)); do
  plot_char $r $c $HORZ
  let count=count+1
done 

plot_char $1 $2 $CORNER_CHAR                   # Draw box angles.
plot_char $1 `expr $2 + $BOX_WIDTH` $CORNER_CHAR
plot_char `expr $1 + $BOX_HEIGHT` $2 $CORNER_CHAR
plot_char `expr $1 + $BOX_HEIGHT` `expr $2 + $BOX_WIDTH` $CORNER_CHAR

echo -ne "\E[0m"             #  Restore old colors.

P_ROWS=`expr $T_ROWS - 1`    #  Put the prompt at bottom of the terminal.

echo -e "\E[${P_ROWS};1H"
}      


# Now, let's try drawing a box.
clear                       # Clear the terminal.
R=2      # Row
C=3      # Column
H=10     # Height
W=45     # Width 
col=1    # Color (red)
draw_box $R $C $H $W $col   # Draw the box.

exit 0

# Exercise:
# --------
# Add the option of printing text within the drawn box.

#!/bin/bash
# color-echo.sh: Echoing text messages in color.

# Modify this script for your own purposes.
# It's easier than hand-coding color.

black='\E[30;47m'
red='\E[31;47m'
green='\E[32;47m'
yellow='\E[33;47m'
blue='\E[34;47m'
magenta='\E[35;47m'
cyan='\E[36;47m'
white='\E[37;47m'


alias Reset="tput sgr0"      #  Reset text attributes to normal
                             #+ without clearing screen.


cecho ()                     # Color-echo.
                             # Argument $1 = message
                             # Argument $2 = color
{
local default_msg="No message passed."
                             # Doesn't really need to be a local variable.

message=${1:-$default_msg}   # Defaults to default message.
color=${2:-$black}           # Defaults to black, if not specified.

  echo -e "$color"
  echo "$message"
  Reset                      # Reset to normal.

  return
}  


# Now, let's try it out.
# ----------------------------------------------------
cecho "Feeling blue..." $blue
cecho "Magenta looks more like purple." $magenta
cecho "Green with envy." $green
cecho "Seeing red?" $red
cecho "Cyan, more familiarly known as aqua." $cyan
cecho "No color passed (defaults to black)."
       # Missing $color argument.
cecho "\"Empty\" color passed (defaults to black)." ""
       # Empty $color argument.
cecho
       # Missing $message and $color arguments.
cecho "" ""
       # Empty $message and $color arguments.
# ----------------------------------------------------

echo

exit 0

# Exercises:
# ---------
# 1) Add the "bold" attribute to the 'cecho ()' function.
# 2) Add options for colored backgrounds.

#!/bin/bash
# horserace.sh: Very simple horserace simulation.
# Author: Stefano Palmeri
# Used with permission.

################################################################
#  Goals of the script:
#  playing with escape sequences and terminal colors.
#
#  Exercise:
#  Edit the script to make it run less randomly,
#+ set up a fake betting shop . . .     
#  Um . . . um . . . it's starting to remind me of a movie . . .
#
#  The script gives each horse a random handicap.
#  The odds are calculated upon horse handicap
#+ and are expressed in European(?) style.
#  E.g., odds=3.75 means that if you bet $1 and win,
#+ you receive $3.75.
# 
#  The script has been tested with a GNU/Linux OS,
#+ using xterm and rxvt, and konsole.
#  On a machine with an AMD 900 MHz processor,
#+ the average race time is 75 seconds.    
#  On faster computers the race time would be lower.
#  So, if you want more suspense, reset the USLEEP_ARG variable.
#
#  Script by Stefano Palmeri.
################################################################

E_RUNERR=65

# Check if md5sum and bc are installed. 
if ! which bc &> /dev/null; then
   echo bc is not installed.  
   echo "Can\'t run . . . "
   exit $E_RUNERR
fi
if ! which md5sum &> /dev/null; then
   echo md5sum is not installed.  
   echo "Can\'t run . . . "
   exit $E_RUNERR
fi

#  Set the following variable to slow down script execution.
#  It will be passed as the argument for usleep (man usleep)  
#+ and is expressed in microseconds (500000 = half a second).
USLEEP_ARG=0  

#  Clean up the temp directory, restore terminal cursor and 
#+ terminal colors -- if script interrupted by Ctl-C.
trap 'echo -en "\E[?25h"; echo -en "\E[0m"; stty echo;\
tput cup 20 0; rm -fr  $HORSE_RACE_TMP_DIR'  TERM EXIT
#  See the chapter on debugging for an explanation of 'trap.'

# Set a unique (paranoid) name for the temp directory the script needs.
HORSE_RACE_TMP_DIR=$HOME/.horserace-`date +%s`-`head -c10 /dev/urandom \
| md5sum | head -c30`

# Create the temp directory and move right in.
mkdir $HORSE_RACE_TMP_DIR
cd $HORSE_RACE_TMP_DIR


#  This function moves the cursor to line $1 column $2 and then prints $3.
#  E.g.: "move_and_echo 5 10 linux" is equivalent to
#+ "tput cup 4 9; echo linux", but with one command instead of two.
#  Note: "tput cup" defines 0 0 the upper left angle of the terminal,
#+ echo defines 1 1 the upper left angle of the terminal.
move_and_echo() {
          echo -ne "\E[${1};${2}H""$3" 
}

# Function to generate a pseudo-random number between 1 and 9. 
random_1_9 ()
{
    head -c10 /dev/urandom | md5sum | tr -d [a-z] | tr -d 0 | cut -c1 
}

#  Two functions that simulate "movement," when drawing the horses. 
draw_horse_one() {
               echo -n " "//$MOVE_HORSE//
}
draw_horse_two(){
              echo -n " "\\\\$MOVE_HORSE\\\\ 
}   


# Define current terminal dimension.
N_COLS=`tput cols`
N_LINES=`tput lines`

# Need at least a 20-LINES X 80-COLUMNS terminal. Check it.
if [ $N_COLS -lt 80 ] || [ $N_LINES -lt 20 ]; then
   echo "`basename $0` needs a 80-cols X 20-lines terminal."
   echo "Your terminal is ${N_COLS}-cols X ${N_LINES}-lines."
   exit $E_RUNERR
fi


# Start drawing the race field.

# Need a string of 80 chars. See below.
BLANK80=`seq -s "" 100 | head -c80`

clear

# Set foreground and background colors to white.
echo -ne '\E[37;47m'

# Move the cursor on the upper left angle of the terminal.
tput cup 0 0 

# Draw six white lines.
for n in `seq 5`; do
      echo $BLANK80   # Use the 80 chars string to colorize the terminal.
done

# Sets foreground color to black. 
echo -ne '\E[30m'

move_and_echo 3 1 "START  1"            
move_and_echo 3 75 FINISH
move_and_echo 1 5 "|"
move_and_echo 1 80 "|"
move_and_echo 2 5 "|"
move_and_echo 2 80 "|"
move_and_echo 4 5 "|  2"
move_and_echo 4 80 "|"
move_and_echo 5 5 "V  3"
move_and_echo 5 80 "V"

# Set foreground color to red. 
echo -ne '\E[31m'

# Some ASCII art.
move_and_echo 1 8 "..@@@..@@@@@...@@@@@.@...@..@@@@..."
move_and_echo 2 8 ".@...@...@.......@...@...@.@......."
move_and_echo 3 8 ".@@@@@...@.......@...@@@@@.@@@@...."
move_and_echo 4 8 ".@...@...@.......@...@...@.@......."
move_and_echo 5 8 ".@...@...@.......@...@...@..@@@@..."
move_and_echo 1 43 "@@@@...@@@...@@@@..@@@@..@@@@."
move_and_echo 2 43 "@...@.@...@.@.....@.....@....."
move_and_echo 3 43 "@@@@..@@@@@.@.....@@@@...@@@.."
move_and_echo 4 43 "@..@..@...@.@.....@.........@."
move_and_echo 5 43 "@...@.@...@..@@@@..@@@@.@@@@.."


# Set foreground and background colors to green.
echo -ne '\E[32;42m'

# Draw  eleven green lines.
tput cup 5 0
for n in `seq 11`; do
      echo $BLANK80
done

# Set foreground color to black. 
echo -ne '\E[30m'
tput cup 5 0

# Draw the fences. 
echo "++++++++++++++++++++++++++++++++++++++\
++++++++++++++++++++++++++++++++++++++++++"

tput cup 15 0
echo "++++++++++++++++++++++++++++++++++++++\
++++++++++++++++++++++++++++++++++++++++++"

# Set foreground and background colors to white.
echo -ne '\E[37;47m'

# Draw three white lines.
for n in `seq 3`; do
      echo $BLANK80
done

# Set foreground color to black.
echo -ne '\E[30m'

# Create 9 files to stores handicaps.
for n in `seq 10 7 68`; do
      touch $n
done  

# Set the first type of "horse" the script will draw.
HORSE_TYPE=2

#  Create position-file and odds-file for every "horse".
#+ In these files, store the current position of the horse,
#+ the type and the odds.
for HN in `seq 9`; do
      touch horse_${HN}_position
      touch odds_${HN}
      echo \-1 > horse_${HN}_position
      echo $HORSE_TYPE >>  horse_${HN}_position
      # Define a random handicap for horse.
       HANDICAP=`random_1_9`
      # Check if the random_1_9 function returned a good value.
      while ! echo $HANDICAP | grep [1-9] &> /dev/null; do
                HANDICAP=`random_1_9`
      done
      # Define last handicap position for horse. 
      LHP=`expr $HANDICAP \* 7 + 3`
      for FILE in `seq 10 7 $LHP`; do
            echo $HN >> $FILE
      done   
     
      # Calculate odds.
      case $HANDICAP in 
              1) ODDS=`echo $HANDICAP \* 0.25 + 1.25 | bc`
                                 echo $ODDS > odds_${HN}
              ;;
              2 | 3) ODDS=`echo $HANDICAP \* 0.40 + 1.25 | bc`
                                       echo $ODDS > odds_${HN}
              ;;
              4 | 5 | 6) ODDS=`echo $HANDICAP \* 0.55 + 1.25 | bc`
                                             echo $ODDS > odds_${HN}
              ;; 
              7 | 8) ODDS=`echo $HANDICAP \* 0.75 + 1.25 | bc`
                                       echo $ODDS > odds_${HN}
              ;; 
              9) ODDS=`echo $HANDICAP \* 0.90 + 1.25 | bc`
                                  echo $ODDS > odds_${HN}
      esac


done


# Print odds.
print_odds() {
tput cup 6 0
echo -ne '\E[30;42m'
for HN in `seq 9`; do
      echo "#$HN odds->" `cat odds_${HN}`
done
}

# Draw the horses at starting line.
draw_horses() {
tput cup 6 0
echo -ne '\E[30;42m'
for HN in `seq 9`; do
      echo /\\$HN/\\"                               "
done
}

print_odds

echo -ne '\E[47m'
# Wait for a enter key press to start the race.
# The escape sequence '\E[?25l' disables the cursor.
tput cup 17 0
echo -e '\E[?25l'Press [enter] key to start the race...
read -s

#  Disable normal echoing in the terminal.
#  This avoids key presses that might "contaminate" the screen
#+ during the race.  
stty -echo

# --------------------------------------------------------
# Start the race.

draw_horses
echo -ne '\E[37;47m'
move_and_echo 18 1 $BLANK80
echo -ne '\E[30m'
move_and_echo 18 1 Starting...
sleep 1

# Set the column of the finish line.
WINNING_POS=74

# Define the time the race started.
START_TIME=`date +%s`

# COL variable needed by following "while" construct.
COL=0    

while [ $COL -lt $WINNING_POS ]; do
                   
          MOVE_HORSE=0     
          
          # Check if the random_1_9 function has returned a good value.
          while ! echo $MOVE_HORSE | grep [1-9] &> /dev/null; do
                MOVE_HORSE=`random_1_9`
          done
          
          # Define old type and position of the "randomized horse".
          HORSE_TYPE=`cat  horse_${MOVE_HORSE}_position | tail -n 1`
          COL=$(expr `cat  horse_${MOVE_HORSE}_position | head -n 1`)
          
          ADD_POS=1
          # Check if the current position is an handicap position. 
          if seq 10 7 68 | grep -w $COL &> /dev/null; then
                if grep -w $MOVE_HORSE $COL &> /dev/null; then
                      ADD_POS=0
                      grep -v -w  $MOVE_HORSE $COL > ${COL}_new
                      rm -f $COL
                      mv -f ${COL}_new $COL
                      else ADD_POS=1
                fi 
          else ADD_POS=1
          fi
          COL=`expr $COL + $ADD_POS`
          echo $COL >  horse_${MOVE_HORSE}_position  # Store new position.
                            
         # Choose the type of horse to draw.         
          case $HORSE_TYPE in 
                1) HORSE_TYPE=2; DRAW_HORSE=draw_horse_two
                ;;
                2) HORSE_TYPE=1; DRAW_HORSE=draw_horse_one 
          esac       
          echo $HORSE_TYPE >>  horse_${MOVE_HORSE}_position
          # Store current type.
         
          # Set foreground color to black and background to green.
          echo -ne '\E[30;42m'
          
          # Move the cursor to new horse position.
          tput cup `expr $MOVE_HORSE + 5` \
	  `cat  horse_${MOVE_HORSE}_position | head -n 1` 
          
          # Draw the horse.
          $DRAW_HORSE
           usleep $USLEEP_ARG
          
           # When all horses have gone beyond field line 15, reprint odds.
           touch fieldline15
           if [ $COL = 15 ]; then
             echo $MOVE_HORSE >> fieldline15  
           fi
           if [ `wc -l fieldline15 | cut -f1 -d " "` = 9 ]; then
               print_odds
               : > fieldline15
           fi           
          
          # Define the leading horse.
          HIGHEST_POS=`cat *position | sort -n | tail -1`          
          
          # Set background color to white.
          echo -ne '\E[47m'
          tput cup 17 0
          echo -n Current leader: `grep -w $HIGHEST_POS *position | cut -c7`\
	  "                              "

done  

# Define the time the race finished.
FINISH_TIME=`date +%s`

# Set background color to green and enable blinking text.
echo -ne '\E[30;42m'
echo -en '\E[5m'

# Make the winning horse blink.
tput cup `expr $MOVE_HORSE + 5` \
`cat  horse_${MOVE_HORSE}_position | head -n 1`
$DRAW_HORSE

# Disable blinking text.
echo -en '\E[25m'

# Set foreground and background color to white.
echo -ne '\E[37;47m'
move_and_echo 18 1 $BLANK80

# Set foreground color to black.
echo -ne '\E[30m'

# Make winner blink.
tput cup 17 0
echo -e "\E[5mWINNER: $MOVE_HORSE\E[25m""  Odds: `cat odds_${MOVE_HORSE}`"\
"  Race time: `expr $FINISH_TIME - $START_TIME` secs"

# Restore cursor and old colors.
echo -en "\E[?25h"
echo -en "\E[0m"

# Restore echoing.
stty echo

# Remove race temp directory.
rm -rf $HORSE_RACE_TMP_DIR

tput cup 19 0

exit 0