标签：style blog color 使用 os strong ar div
[tough@localhost ~]$ expr 6+2 6+2 [tough@localhost ~]$ expr 6 + 2 8 [tough@localhost ~]$ expr 6 - 2 4 [tough@localhost ~]$ expr 6 / 2 3 [tough@localhost ~]$ expr 6 * 2 expr: syntax error [tough@localhost ~]$ expr 6 \* 2 12 [tough@localhost ~]$ expr 6 + 3 - 5 4
[tough@localhost ~]$ expr 1.4 / 2 expr: non-numeric argument [tough@localhost ~]$ echo $? 2 [tough@localhost ~]$ expr 2 / 2 1 [tough@localhost ~]$ echo $? 0
[tough@localhost ~]$ expr substr "Hello World" 7 5 World
2）提取指定字符的下标
[tough@localhost ~]$ expr index "123#45" "#" 4
标签：style blog color 使用 os strong ar div
原文地址：http://www.cnblogs.com/toughhou/p/3898409.html
