Use the shell to determine whether a user exists (the user name is passed by parameter)

Write a script:

1. Use function to realize:

To determine whether a user exists, the user name passed through the parameters;

If present, the shell and UID of this user are displayed

If it does not exist, it is said that the user does not exist;

2, prompts the user to enter the user name, then passes it to the above function;

3, not exit after the judgment, but prompts the user to continue to enter other user name, or input (quit) exit;

No nonsense, the code is as follows:

#!/bin/bash  
#Author: MOS  
#Script name:funUinfo.sh  
#Date & time:2012-10-09/21:06:02  
#Version: 1.0.1  
#Description:  
#  
#定义函数  
Find_u () {  
#判断输入值是否为空, if null, function ends, return value 1 [-  
Z $] && Return 1  
#判断用户是否存在, exists to display the request, does not exist, the function ends, returns a value of 1  
if ID &>/dev/null then 
    echo "" Is ' id-u ' 
 echo "Shell is ' grep" ^$1: "/etc/passwd \
    |cut-d ': '-f7 '"  
else return
    1  
fi  
}  
#循环执行 to  Meet the topic requirements while  
:;d o
read-p "Please input A username[quit to exit]:" User 
    if [$User = Quit];then 
        exit 0  
    Else
        find_u $User 
        res=$?  
        [$Res-eq 1] && echo "No such $User."
    Fi done