Alternatively you can use the octal form of the control code , " - 033 " , but the prompt setting doesn t understand this syntax itself , so you have to use " echo " and command substitution , as shown in the next example 当然也可以使用八进制格式的控制码, " 033 " ,但是prompt设置并不能够理解这个语法本身,所以您得使用" echo "和命令替换,如下例所示:
And up are considered backreferences if there is a backreference corresponding to that number ; otherwise , they are interpreted as octal codes unless the starting digits are 8 or 9 , in which case they are treated as literal " 8 " and " 9 " 和更高位表达式在具有与该号码对应的反向引用时被视作反向引用;否则,它们会被解释为八进制代码(除非起始位是8或9 ,在这种情况下它们被视为原义的“ 8 ”和“ 9 ” ) 。
of or pertaining to a number system having 8 as its base; "an octal digit"
百科解释
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Octal numerals can be made from binary numerals by grouping consecutive binary digits into groups of three (starting from the right).