colorizing.html

Shall高级编程

><PRE
CLASS="SCREEN"
> <TT
CLASS="PROMPT"
>bash$ </TT
><TT
CLASS="USERINPUT"
><B
>echo -e '\E[34;47mThis prints in blue.'; tput sgr0</B
></TT
>
 
 
 <TT
CLASS="PROMPT"
>bash$ </TT
><TT
CLASS="USERINPUT"
><B
>echo -e '\E[33;44m'"yellow text on blue background"; tput sgr0</B
></TT
>
 
 
 <TT
CLASS="PROMPT"
>bash$ </TT
><TT
CLASS="USERINPUT"
><B
>echo -e '\E[1;33;44m'"BOLD yellow text on blue background"; tput sgr0</B
></TT
>
 	      </PRE
></TD
></TR
></TABLE
>
	      </P
><DIV
CLASS="NOTE"
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="common/note.png"
HSPACE="5"
ALT="Note"></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>It's usually advisable to set the
	  <I
CLASS="FIRSTTERM"
>bold</I
> attribute for light-colored foreground
	  text.</P
></TD
></TR
></TABLE
></DIV
><P
>The <B
CLASS="COMMAND"
>tput sgr0</B
> restores the
		terminal settings to normal. Omitting this lets all
	        subsequent output from that particular terminal remain
	        blue.</P
><DIV
CLASS="NOTE"
><TABLE
CLASS="NOTE"
WIDTH="100%"
BORDER="0"
><TR
><TD
WIDTH="25"
ALIGN="CENTER"
VALIGN="TOP"
><IMG
SRC="common/note.png"
HSPACE="5"
ALT="Note"></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><P
>Since <B
CLASS="COMMAND"
>tput sgr0</B
> fails to restore
	        terminal settings under certain circumstances,
		<B
CLASS="COMMAND"
>echo -ne \E[0m</B
> may be a better choice.</P
></TD
></TR
></TABLE
></DIV
><P
><A
NAME="COLORIZTEMPL"
></A
></P
><TABLE
CLASS="SIDEBAR"
BORDER="1"
CELLPADDING="5"
><TR
><TD
><DIV
CLASS="SIDEBAR"
><A
NAME="AEN18752"
></A
><P
>Use the following template for writing colored text on a colored
	background.</P
><P
>	  <TT
CLASS="USERINPUT"
><B
>echo -e '\E[COLOR1;COLOR2mSome text goes here.'</B
></TT
>
        </P
><P
>The <SPAN
CLASS="QUOTE"
>"\E["</SPAN
> begins the escape sequence.
	  The semicolon-separated numbers <SPAN
CLASS="QUOTE"
>"COLOR1"</SPAN
> and
	  <SPAN
CLASS="QUOTE"
>"COLOR2"</SPAN
> specify a foreground and a background
	  color, according to the table below. (The order of the
	  numbers does not matter, since the foreground and background
	  numbers fall in non-overlapping ranges.) The <SPAN
CLASS="QUOTE"
>"m"</SPAN
>
	  terminates the escape sequence, and the text begins immediately
	  after that.</P
><P
>Note also that <A
HREF="variables.html#SNGLQUO"
>single quotes</A
>
	  enclose the remainder of the command sequence following the
	  <B
CLASS="COMMAND"
>echo -e</B
>.</P
></DIV
></TD
></TR
></TABLE
><P
>The numbers in the following table work for an
	  <I
CLASS="FIRSTTERM"
>rxvt</I
> terminal. Results may vary for other
	  terminal emulators.</P
><P
><A
NAME="COLORIZTABLE"
></A
></P
><DIV
CLASS="TABLE"
><HR><A
NAME="AEN18768"
></A
><P
><B
>Table 33-2. Numbers representing colors in Escape Sequences</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><THEAD
><TR
><TH
ALIGN="LEFT"
VALIGN="TOP"
>Color</TH
><TH
ALIGN="LEFT"
VALIGN="TOP"
>Foreground</TH
><TH
ALIGN="LEFT"
VALIGN="TOP"
>Background</TH
></TR
></THEAD
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>black</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>30</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>40</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>red</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>31</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>41</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>green</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>32</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>42</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>yellow</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>33</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>43</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>blue</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>34</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>44</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>magenta</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>35</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>45</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>cyan</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>36</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>46</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="OPTION"
>white</TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>37</TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>47</TD
></TR
></TBODY
></TABLE
><HR></DIV
><DIV
CLASS="EXAMPLE"
><HR><A
NAME="COLORECHO"
></A
><P
><B
>Example 33-13. Echoing colored text</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>   1&nbsp;#!/bin/bash
   2&nbsp;# color-echo.sh: Echoing text messages in color.
   3&nbsp;
   4&nbsp;# Modify this script for your own purposes.
   5&nbsp;# It's easier than hand-coding color.
   6&nbsp;
   7&nbsp;black='\E[30;47m'
   8&nbsp;red='\E[31;47m'
   9&nbsp;green='\E[32;47m'
  10&nbsp;yellow='\E[33;47m'
  11&nbsp;blue='\E[34;47m'
  12&nbsp;magenta='\E[35;47m'
  13&nbsp;cyan='\E[36;47m'
  14&nbsp;white='\E[37;47m'
  15&nbsp;
  16&nbsp;
  17&nbsp;alias Reset="tput sgr0"      #  Reset text attributes to normal
  18&nbsp;                             #+ without clearing screen.
  19&nbsp;
  20&nbsp;
  21&nbsp;cecho ()                     # Color-echo.
  22&nbsp;                             # Argument $1 = message
  23&nbsp;                             # Argument $2 = color
  24&nbsp;{
  25&nbsp;local default_msg="No message passed."
  26&nbsp;                             # Doesn't really need to be a local variable.
  27&nbsp;
  28&nbsp;message=${1:-$default_msg}   # Defaults to default message.
  29&nbsp;color=${2:-$black}           # Defaults to black, if not specified.
  30&nbsp;
  31&nbsp;  echo -e "$color"
  32&nbsp;  echo "$message"
  33&nbsp;  Reset                      # Reset to normal.
  34&nbsp;
  35&nbsp;  return
  36&nbsp;}  
  37&nbsp;
  38&nbsp;
  39&nbsp;# Now, let's try it out.
  40&nbsp;# ----------------------------------------------------
  41&nbsp;cecho "Feeling blue..." $blue
  42&nbsp;cecho "Magenta looks more like purple." $magenta
  43&nbsp;cecho "Green with envy." $green
  44&nbsp;cecho "Seeing red?" $red
  45&nbsp;cecho "Cyan, more familiarly known as aqua." $cyan
  46&nbsp;cecho "No color passed (defaults to black)."
  47&nbsp;       # Missing $color argument.
  48&nbsp;cecho "\"Empty\" color passed (defaults to black)." ""
  49&nbsp;       # Empty $color argument.
  50&nbsp;cecho
  51&nbsp;       # Missing $message and $color arguments.
  52&nbsp;cecho "" ""
  53&nbsp;       # Empty $message and $color arguments.
  54&nbsp;# ----------------------------------------------------
  55&nbsp;
  56&nbsp;echo
  57&nbsp;
  58&nbsp;exit 0
  59&nbsp;
  60&nbsp;# Exercises:
  61&nbsp;# ---------
  62&nbsp;# 1) Add the "bold" attribute to the 'cecho ()' function.
  63&nbsp;# 2) Add options for colored backgrounds.</PRE
></TD
></TR
></TABLE
><HR></DIV
><P
><A
NAME="HORSERACEREF"
></A
></P
><DIV
CLASS="EXAMPLE"
><HR><A
NAME="HORSERACE"
></A
><P
><B
>Example 33-14. A <SPAN
CLASS="QUOTE"
>"horserace"</SPAN
> game</B
></P
><TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="PROGRAMLISTING"
>   1&nbsp;#!/bin/bash
   2&nbsp;# horserace.sh: Very simple horserace simulation.
   3&nbsp;# Author: Stefano Palmeri
   4&nbsp;# Used with permission.
   5&nbsp;
   6&nbsp;################################################################
   7&nbsp;#  Goals of the script:
   8&nbsp;#  playing with escape sequences and terminal colors.
   9&nbsp;#
  10&nbsp;#  Exercise:
  11&nbsp;#  Edit the script to make it run less randomly,
  12&nbsp;#+ set up a fake betting shop . . .     
  13&nbsp;#  Um . . . um . . . it's starting to remind me of a movie . . .
  14&nbsp;#
  15&nbsp;#  The script gives each horse a random handicap.
  16&nbsp;#  The odds are calculated upon horse handicap
  17&nbsp;#+ and are expressed in European(?) style.
  18&nbsp;#  E.g., odds=3.75 means that if you bet $1 and win,
  19&nbsp;#+ you receive $3.75.
  20&nbsp;# 
  21&nbsp;#  The script has been tested with a GNU/Linux OS,
  22&nbsp;#+ using xterm and rxvt, and konsole.
  23&nbsp;#  On a machine with an AMD 900 MHz processor,
  24&nbsp;#+ the average race time is 75 seconds.    
  25&nbsp;#  On faster computers the race time would be lower.
  26&nbsp;#  So, if you want more suspense, reset the USLEEP_ARG variable.
  27&nbsp;#
  28&nbsp;#  Script by Stefano Palmeri.
  29&nbsp;################################################################
  30&nbsp;
  31&nbsp;E_RUNERR=65
  32&nbsp;
  33&nbsp;# Check if md5sum and bc are installed. 
  34&nbsp;if ! which bc &#38;&#62; /dev/null; then
  35&nbsp;   echo bc is not installed.  
  36&nbsp;   echo "Can\'t run . . . "
  37&nbsp;   exit $E_RUNERR
  38&nbsp;fi
  39&nbsp;if ! which md5sum &#38;&#62; /dev/null; then
  40&nbsp;   echo md5sum is not installed.  
  41&nbsp;   echo "Can\'t run . . . "
  42&nbsp;   exit $E_RUNERR
  43&nbsp;fi
  44&nbsp;
  45&nbsp;#  Set the following variable to slow down script execution.
  46&nbsp;#  It will be passed as the argument for usleep (man usleep)  
  47&nbsp;#+ and is expressed in microseconds (500000 = half a second).
  48&nbsp;USLEEP_ARG=0  
  49&nbsp;
  50&nbsp;#  Clean up the temp directory, restore terminal cursor and 
  51&nbsp;#+ terminal colors -- if script interrupted by Ctl-C.
  52&nbsp;trap 'echo -en "\E[?25h"; echo -en "\E[0m"; stty echo;\
  53&nbsp;tput cup 20 0; rm -fr  $HORSE_RACE_TMP_DIR'  TERM EXIT
  54&nbsp;#  See the chapter on debugging for an explanation of 'trap.'
  55&nbsp;