colorizing.html

Shall高级编程

  56 # Set a unique (paranoid) name for the temp directory the script needs.
  57 HORSE_RACE_TMP_DIR=$HOME/.horserace-`date +%s`-`head -c10 /dev/urandom \
  58 | md5sum | head -c30`
  59 
  60 # Create the temp directory and move right in.
  61 mkdir $HORSE_RACE_TMP_DIR
  62 cd $HORSE_RACE_TMP_DIR
  63 
  64 
  65 #  This function moves the cursor to line $1 column $2 and then prints $3.
  66 #  E.g.: "move_and_echo 5 10 linux" is equivalent to
  67 #+ "tput cup 4 9; echo linux", but with one command instead of two.
  68 #  Note: "tput cup" defines 0 0 the upper left angle of the terminal,
  69 #+ echo defines 1 1 the upper left angle of the terminal.
  70 move_and_echo() {
  71           echo -ne "\E[${1};${2}H""$3" 
  72 }
  73 
  74 # Function to generate a pseudo-random number between 1 and 9. 
  75 random_1_9 ()
  76 {
  77     head -c10 /dev/urandom | md5sum | tr -d [a-z] | tr -d 0 | cut -c1 
  78 }
  79 
  80 #  Two functions that simulate "movement," when drawing the horses. 
  81 draw_horse_one() {
  82                echo -n " "//$MOVE_HORSE//
  83 }
  84 draw_horse_two(){
  85               echo -n " "\\\\$MOVE_HORSE\\\\ 
  86 }   
  87 
  88 
  89 # Define current terminal dimension.
  90 N_COLS=`tput cols`
  91 N_LINES=`tput lines`
  92 
  93 # Need at least a 20-LINES X 80-COLUMNS terminal. Check it.
  94 if [ $N_COLS -lt 80 ] || [ $N_LINES -lt 20 ]; then
  95    echo "`basename $0` needs a 80-cols X 20-lines terminal."
  96    echo "Your terminal is ${N_COLS}-cols X ${N_LINES}-lines."
  97    exit $E_RUNERR
  98 fi
  99 
 100 
 101 # Start drawing the race field.
 102 
 103 # Need a string of 80 chars. See below.
 104 BLANK80=`seq -s "" 100 | head -c80`
 105 
 106 clear
 107 
 108 # Set foreground and background colors to white.
 109 echo -ne '\E[37;47m'
 110 
 111 # Move the cursor on the upper left angle of the terminal.
 112 tput cup 0 0 
 113 
 114 # Draw six white lines.
 115 for n in `seq 5`; do
 116       echo $BLANK80   # Use the 80 chars string to colorize the terminal.
 117 done
 118 
 119 # Sets foreground color to black. 
 120 echo -ne '\E[30m'
 121 
 122 move_and_echo 3 1 "START  1"            
 123 move_and_echo 3 75 FINISH
 124 move_and_echo 1 5 "|"
 125 move_and_echo 1 80 "|"
 126 move_and_echo 2 5 "|"
 127 move_and_echo 2 80 "|"
 128 move_and_echo 4 5 "|  2"
 129 move_and_echo 4 80 "|"
 130 move_and_echo 5 5 "V  3"
 131 move_and_echo 5 80 "V"
 132 
 133 # Set foreground color to red. 
 134 echo -ne '\E[31m'
 135 
 136 # Some ASCII art.
 137 move_and_echo 1 8 "..@@@..@@@@@...@@@@@.@...@..@@@@..."
 138 move_and_echo 2 8 ".@...@...@.......@...@...@.@......."
 139 move_and_echo 3 8 ".@@@@@...@.......@...@@@@@.@@@@...."
 140 move_and_echo 4 8 ".@...@...@.......@...@...@.@......."
 141 move_and_echo 5 8 ".@...@...@.......@...@...@..@@@@..."
 142 move_and_echo 1 43 "@@@@...@@@...@@@@..@@@@..@@@@."
 143 move_and_echo 2 43 "@...@.@...@.@.....@.....@....."
 144 move_and_echo 3 43 "@@@@..@@@@@.@.....@@@@...@@@.."
 145 move_and_echo 4 43 "@..@..@...@.@.....@.........@."
 146 move_and_echo 5 43 "@...@.@...@..@@@@..@@@@.@@@@.."
 147 
 148 
 149 # Set foreground and background colors to green.
 150 echo -ne '\E[32;42m'
 151 
 152 # Draw  eleven green lines.
 153 tput cup 5 0
 154 for n in `seq 11`; do
 155       echo $BLANK80
 156 done
 157 
 158 # Set foreground color to black. 
 159 echo -ne '\E[30m'
 160 tput cup 5 0
 161 
 162 # Draw the fences. 
 163 echo "++++++++++++++++++++++++++++++++++++++\
 164 ++++++++++++++++++++++++++++++++++++++++++"
 165 
 166 tput cup 15 0
 167 echo "++++++++++++++++++++++++++++++++++++++\
 168 ++++++++++++++++++++++++++++++++++++++++++"
 169 
 170 # Set foreground and background colors to white.
 171 echo -ne '\E[37;47m'
 172 
 173 # Draw three white lines.
 174 for n in `seq 3`; do
 175       echo $BLANK80
 176 done
 177 
 178 # Set foreground color to black.
 179 echo -ne '\E[30m'
 180 
 181 # Create 9 files to stores handicaps.
 182 for n in `seq 10 7 68`; do
 183       touch $n
 184 done  
 185 
 186 # Set the first type of "horse" the script will draw.
 187 HORSE_TYPE=2
 188 
 189 #  Create position-file and odds-file for every "horse".
 190 #+ In these files, store the current position of the horse,
 191 #+ the type and the odds.
 192 for HN in `seq 9`; do
 193       touch horse_${HN}_position
 194       touch odds_${HN}
 195       echo \-1 > horse_${HN}_position
 196       echo $HORSE_TYPE >>  horse_${HN}_position
 197       # Define a random handicap for horse.
 198        HANDICAP=`random_1_9`
 199       # Check if the random_1_9 function returned a good value.
 200       while ! echo $HANDICAP | grep [1-9] &> /dev/null; do
 201                 HANDICAP=`random_1_9`
 202       done
 203       # Define last handicap position for horse. 
 204       LHP=`expr $HANDICAP \* 7 + 3`
 205       for FILE in `seq 10 7 $LHP`; do
 206             echo $HN >> $FILE
 207       done   
 208      
 209       # Calculate odds.
 210       case $HANDICAP in 
 211               1) ODDS=`echo $HANDICAP \* 0.25 + 1.25 | bc`
 212                                  echo $ODDS > odds_${HN}
 213               ;;
 214               2 | 3) ODDS=`echo $HANDICAP \* 0.40 + 1.25 | bc`
 215                                        echo $ODDS > odds_${HN}
 216               ;;
 217               4 | 5 | 6) ODDS=`echo $HANDICAP \* 0.55 + 1.25 | bc`
 218                                              echo $ODDS > odds_${HN}
 219               ;; 
 220               7 | 8) ODDS=`echo $HANDICAP \* 0.75 + 1.25 | bc`
 221                                        echo $ODDS > odds_${HN}
 222               ;; 
 223               9) ODDS=`echo $HANDICAP \* 0.90 + 1.25 | bc`
 224                                   echo $ODDS > odds_${HN}
 225       esac
 226 
 227 
 228 done
 229 
 230 
 231 # Print odds.
 232 print_odds() {
 233 tput cup 6 0
 234 echo -ne '\E[30;42m'
 235 for HN in `seq 9`; do
 236       echo "#$HN odds->" `cat odds_${HN}`
 237 done
 238 }
 239 
 240 # Draw the horses at starting line.
 241 draw_horses() {
 242 tput cup 6 0
 243 echo -ne '\E[30;42m'
 244 for HN in `seq 9`; do
 245       echo /\\$HN/\\"                               "
 246 done
 247 }
 248 
 249 print_odds
 250 
 251 echo -ne '\E[47m'
 252 # Wait for a enter key press to start the race.
 253 # The escape sequence '\E[?25l' disables the cursor.
 254 tput cup 17 0
 255 echo -e '\E[?25l'Press [enter] key to start the race...
 256 read -s
 257 
 258 #  Disable normal echoing in the terminal.
 259 #  This avoids key presses that might "contaminate" the screen
 260 #+ during the race.  
 261 stty -echo
 262 
 263 # --------------------------------------------------------
 264 # Start the race.
 265 
 266 draw_horses
 267 echo -ne '\E[37;47m'
 268 move_and_echo 18 1 $BLANK80
 269 echo -ne '\E[30m'
 270 move_and_echo 18 1 Starting...
 271 sleep 1
 272 
 273 # Set the column of the finish line.
 274 WINNING_POS=74
 275 
 276 # Define the time the race started.
 277 START_TIME=`date +%s`
 278 
 279 # COL variable needed by following "while" construct.
 280 COL=0    
 281 
 282 while [ $COL -lt $WINNING_POS ]; do
 283                    
 284           MOVE_HORSE=0     
 285           
 286           # Check if the random_1_9 function has returned a good value.
 287           while ! echo $MOVE_HORSE | grep [1-9] &> /dev/null; do
 288                 MOVE_HORSE=`random_1_9`
 289           done
 290           
 291           # Define old type and position of the "randomized horse".
 292           HORSE_TYPE=`cat  horse_${MOVE_HORSE}_position | tail -n 1`
 293           COL=$(expr `cat  horse_${MOVE_HORSE}_position | head -n 1`)
 294           
 295           ADD_POS=1
 296           # Check if the current position is an handicap position. 
 297           if seq 10 7 68 | grep -w $COL &> /dev/null; then
 298                 if grep -w $MOVE_HORSE $COL &> /dev/null; then
 299                       ADD_POS=0
 300                       grep -v -w  $MOVE_HORSE $COL > ${COL}_new
 301                       rm -f $COL
 302                       mv -f ${COL}_new $COL
 303                       else ADD_POS=1
 304                 fi 
 305           else ADD_POS=1
 306           fi
 307           COL=`expr $COL + $ADD_POS`
 308           echo $COL >  horse_${MOVE_HORSE}_position  # Store new position.
 309                             
 310          # Choose the type of horse to draw.         
 311           case $HORSE_TYPE in 
 312                 1) HORSE_TYPE=2; DRAW_HORSE=draw_horse_two
 313                 ;;
 314                 2) HORSE_TYPE=1; DRAW_HORSE=draw_horse_one 
 315           esac       
 316           echo $HORSE_TYPE >>  horse_${MOVE_HORSE}_position
 317           # Store current type.
 318          
 319           # Set foreground color to black and background to green.
 320           echo -ne '\E[30;42m'
 321           
 322           # Move the cursor to new horse position.
 323           tput cup `expr $MOVE_HORSE + 5` \
 324 	  `cat  horse_${MOVE_HORSE}_position | head -n 1` 
 325           
 326           # Draw the horse.
 327           $DRAW_HORSE
 328            usleep $USLEEP_ARG
 329           
 330            # When all horses have gone beyond field line 15, reprint odds.
 331            touch fieldline15
 332            if [ $COL = 15 ]; then
 333              echo $MOVE_HORSE >> fieldline15  
 334            fi
 335            if [ `wc -l fieldline15 | cut -f1 -d " "` = 9 ]; then
 336                print_odds
 337                : > fieldline15
 338            fi           
 339           
 340           # Define the leading horse.
 341           HIGHEST_POS=`cat *position | sort -n | tail -1`          
 342           
 343           # Set background color to white.
 344           echo -ne '\E[47m'
 345           tput cup 17 0
 346           echo -n Current leader: `grep -w $HIGHEST_POS *position | cut -c7`\
 347 	  "                              "
 348 
 349 done  
 350 
 351 # Define the time the race finished.
 352 FINISH_TIME=`date +%s`
 353 
 354 # Set background color to green and enable blinking text.
 355 echo -ne '\E[30;42m'
 356 echo -en '\E[5m'
 357 
 358 # Make the winning horse blink.
 359 tput cup `expr $MOVE_HORSE + 5` \
 360 `cat  horse_${MOVE_HORSE}_position | head -n 1`
 361 $DRAW_HORSE
 362 
 363 # Disable blinking text.
 364 echo -en '\E[25m'
 365 
 366 # Set foreground and background color to white.
 367 echo -ne '\E[37;47m'
 368 move_and_echo 18 1 $BLANK80
 369 
 370 # Set foreground color to black.
 371 echo -ne '\E[30m'
 372 
 373 # Make winner blink.
 374 tput cup 17 0
 375 echo -e "\E[5mWINNER: $MOVE_HORSE\E[25m""  Odds: `cat odds_${MOVE_HORSE}`"\
 376 "  Race time: `expr $FINISH_TIME - $START_TIME` secs"
 377 
 378 # Restore cursor and old colors.
 379 echo -en "\E[?25h"
 380 echo -en "\E[0m"
 381 
 382 # Restore echoing.
 383 stty echo
 384 
 385 # Remove race temp directory.
 386 rm -rf $HORSE_RACE_TMP_DIR
 387 
 388 tput cup 19 0
 389 
 390&nbsp;exit 0</PRE
></TD
></TR
></TABLE
><HR></DIV
><P
>See also <A
HREF="contributed-scripts.html#HASHEXAMPLE"
>Example A-23</A
> and <A
HREF="contributed-scripts.html#HOMEWORK"
>Example A-40</A
>.</P
><DIV
CLASS="CAUTION"
><TABLE
CLASS="CAUTION"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="common/caution.png"
HSPACE="5"
ALT="Caution"></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>There is, however, a major problem with all
	  this. <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>ANSI escape sequences are emphatically
	  non-portable.</I
></SPAN
> What works fine on some terminal
	  emulators (or the console) may work differently, or not
	  at all, on others. A <SPAN
CLASS="QUOTE"
>"colorized"</SPAN
> script that
	  looks stunning on the script author's machine may produce
	  unreadable output on someone else's. This greatly compromises
	  the usefulness of <SPAN
CLASS="QUOTE"
>"colorizing"</SPAN
> scripts, and
	  possibly relegates this technique to the status of a gimmick
	  or even a <SPAN
CLASS="QUOTE"
>"toy"</SPAN
>.</P
></TD
></TR
></TABLE
></DIV
><P
>Moshe Jacobson's <B
CLASS="COMMAND"
>color</B
> utility  
	  (<A
HREF="http://runslinux.net/projects.html#color"
TARGET="_top"
>http://runslinux.net/projects.html#color</A
>)
	  considerably simplifies using ANSI escape sequences. It
	  substitutes a clean and logical syntax for the clumsy constructs
	  just discussed.</P
><P
>Henry/teikedvl has likewise created a utility (<A
HREF="http://scriptechocolor.sourceforge.net/"
TARGET="_top"
>http://scriptechocolor.sourceforge.net/</A
>) to simplify creation of colorized scripts.</P
></DIV
><H3
CLASS="FOOTNOTES"
>Notes</H3
><TABLE
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CLASS="FOOTNOTES"
WIDTH="100%"
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.AEN18700"
HREF="colorizing.html#AEN18700"
>[1]</A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
><SPAN
CLASS="ACRONYM"
>ANSI</SPAN
> is, of course, the
	     acronym for the American National Standards
	     Institute. This august body establishes and maintains
	     various technical and industrial standards.</P
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