Shell script to list all users in /etc/passwd file

milestone · 09-15-2007, 07:27 AM

Hi,

I need a shell script which lists all users listed in /etc/passwd file. I don't know how to extract them. Please help me to write this type of script.

Is it possible to get the users with different shell from the same script? Please reply...

macemoneta · 09-15-2007, 07:45 AM

It's not a script, just one command:

Code:

awk -F: '{print $1}' /etc/passwd

If you want users with a specific shell:

Code:

grep "/sbin/nologin" /etc/passwd | awk -F: '{print $1}'

ghostdog74 · 09-15-2007, 10:08 AM

Quote:

Originally Posted by macemoneta

Code:

grep "/sbin/nologin" /etc/passwd | awk -F: '{print $1}'

No need for grep. awk does it all.

Code:

awk -F":" '$7 ~ /\/bin\/bash/ {print $1}' /etc/passwd

daemonkl · 09-15-2007, 12:24 PM

then if I wanted to make this as a command, how should i proceed?
i've tried to put the command in a file name "list" and chmod +x list

Code:

#!/bin/sh
awk -F: '{print $1}' /etc/passwd

when I issue command list:

[user@slackware:~]$ list
-bash: list: command not found

i'm still new to shell scripting

macemoneta · 09-15-2007, 12:39 PM

You need to put the script in a directory in your PATH, or specify an explicit path. To see your current PATH enter:

echo $PATH

To run the 'list' command from the current directory:

./list

daemonkl · 09-15-2007, 12:44 PM

thanks macemoneta,

i have moved the "list" file to /home/user/bin

instead of issuing ./list, i can now fire "list" without the ./ anywhere

thanks again!

HowDoIProgramIt · 09-15-2007, 12:57 PM

Quote:

Originally Posted by daemonkl

then if I wanted to make this as a command, how should i proceed?

I would make it a shell function:

Code:

function ListAllUsers()
{
   awk -F: '{print $1}' /etc/passwd
}

The "function" keyword before ListAllUsers is optional; I personally don't usually include it.

If you wanted to have it available each time you logged in, you could put it in your ~/.bashrc; if you have several functions you want to put in your .bashrc, you're probably better off putting them in a separate file, such as ~/myfunctions, and putting either

Code:

. ~/myfunctions

or

Code:

source ~/myfunctions

in your .bashrc (the two commands are equivalent).

FWIW, for files that I only want to source, I don't put a "she-bang" at the start of them, or mark them +x; and, I don't use the same extension for them that I do for out-right scripts. That tends to save me at least some grief.

- Larry