linux中预留的$变量

 1 #!/bin/bash
 2 
 3 # The differences between $* $@ "$*" "$@"
 4 
 5 echo Dollar star is $* # 空格未保留
 6 echo "Dollar star in double quotes is $*" # 引号内的空格被保留
 7 echo Dollar at is $@ # 空格未保留
 8 echo "Dollar at in double quotes is $@" #引号的空格被保留
 9 
10 echo
11 echo "Looping through Dollar Star" # 不引用$* 每个单词被当成独立的单词
12 for i in $*
13 do
14         echo "Parameter is $i"
15 done
16 
17 echo
18 echo "Looping through Dollar Star with double quotes" # 使用"$*"整个参数列表被当成一个参数
19 for i in "$*"
20 do
21         echo "Parameter is $i"
22 done
23 
24 echo
25 echo "Looping through Dollar At" # 不引用的#@与$*一样
26 for i in $@
27 do
28         echo "Parameter is $i"
29 done
30 
31 echo
32 echo "Looping through Dollar At in double quotes" # "$@"保留调用者的假设，引号内的作为一个参数，且保留空格
33 for i in "$@"
34 do
35         echo "Parameter is $i"
36 done

bash 01defaultParam.sh  "hello world" two