101超酷脚本学习笔记 ：11节 ANSI Color Sequences

按原书的脚本，发现不能显示出效果。

#!/bin/sh
initializeANSI()
{
  esc="\033" # if this doesn't work, enter an ESC directly

  blackf="${esc}[30m";   redf="${esc}[31m";    greenf="${esc}[32m"
  yellowf="${esc}[33m"   bluef="${esc}[34m";   purplef="${esc}[35m"
  cyanf="${esc}[36m";    whitef="${esc}[37m"

  blackb="${esc}[40m";   redb="${esc}[41m";    greenb="${esc}[42m"
  yellowb="${esc}[43m"   blueb="${esc}[44m";   purpleb="${esc}[45m"
  cyanb="${esc}[46m";    whiteb="${esc}[47m"

  boldon="${esc}[1m";    boldoff="${esc}[22m"
  italicson="${esc}[3m"; italicsoff="${esc}[23m"
  ulon="${esc}[4m";      uloff="${esc}[24m"
  invon="${esc}[7m";     invoff="${esc}[27m"

  reset="${esc}[0m"
}
initializeANSI

cat << EOF
${yellowf}This is a phrase in yellow${redb} and red${reset}
${boldon}This is bold${ulon} this is italics${reset} bye bye
${italicson}This is italics${italicsoff} and this is not
${ulon}This is ul${uloff} and this is not
${invon}This is inv${invoff} and this is not
${yellowf}${redb}Warning I ${yellowb}${redf}Warning II${reset}
EOF

显示效果是这样的：

\033[33mThis is a phrase in yellow\033[41m and red\033[0m
\033[1mThis is bold\033[4m this is italics\033[0m bye bye
\033[3mThis is italics\033[23m and this is not
\033[4mThis is ul\033[24m and this is not
\033[7mThis is inv\033[27m and this is not
\033[33m\033[41mWarning I \033[43m\033[31mWarning II\033[0m

这是由于\033是一个特殊字符，代表ESC键值，可以在VIM中，进入插入模式，然后按Crl+v,再按ESC，得到一个"^["这样的字符。直接输入^和[这2个字符是没有用的。

esc="^["# if this doesn't work, enter an ESC directly

修改后，效果如下：

This is a phrase in yellow and red"

This is bold this is italics bye bye

This is italics and this is not

This is ul and this is not

This is inv and this is not

Warning I Warning II