#yyds干货盘点#shell进阶之shift与select相关技术

Posted 2021-12-13 王华_linux

1.循环控制命令 shift

shift [n] 用于将参量列表 list 左移指定次数，缺省为左移一次。参量列表 list 一旦被移动，最左端的那个参数就从列表中删除。while 循环遍历位置参量列表时，常用到 shift

[root@c7-147 ~]#help shift 
shift: shift [n]
    Shift positional parameters.
    Rename the positional parameters $N+1,$N+2 ... to $1,$2 ...  If N is
    not given, it is assumed to be 1.
    Exit Status:
    Returns success unless N is negative or greater than $#.

shift 创建用户账号

[root@c7-147 ~]#help test
test: test [expr]
      -z STRING      True if string is empty.
      -n STRING
         STRING      True if string is not empty.

#创建用户