Check Whether a User Exists

Question

I want to create a script to check whether a user exists. I am using the logic below:

# getent passwd test > /dev/null 2&>1
# echo $?
0
# getent pa         


        

Answer 1

I like this nice one line solution

getent passwd username > /dev/null 2&>1 && echo yes || echo no

and in script:

#!/bin/bash

if [ "$1" != "" ]; then
        getent passwd $1 > /dev/null 2&>1 && (echo yes; exit 0) || (echo no; exit 2)
else
        echo "missing username"
        exit -1
fi

use:

[mrfish@yoda ~]$ ./u_exists.sh root
yes
[mrfish@yoda ~]$ echo $?
0

[mrfish@yoda ~]$ ./u_exists.sh
missing username
[mrfish@yoda ~]$ echo $?
255

[mrfish@yoda ~]$ ./u_exists.sh aaa
no
[mrfish@indegy ~]$ echo $?
2