Check if a variable is having value Post: 302769390

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Top Forums Shell Programming and Scripting Check if a variable is having value Post 302769390 by anil510 on Tuesday 12th of February 2013 05:42:49 AM

02-12-2013

Registered User

Check if a variable is having value

I have a script /root/asas with following contents.

Code:

#!/bin/bash

ha=`cat /etc/passwd | grep sandra`

if [ -n $ha ]; then
        echo "Sandra is in /etc/passwd"
        echo "variable ha is $ha"
else
        echo "Sandra is NOT in /etc/passwd"
        echo "variable ha is $ha"

fi

What I need is when "cat" does not find sandra in /etc/passwd, it should print "Sandra is NOT in /etc/passwd". But this is not giving correct result. See below.

Code:

[root@server ]# grep sandra /etc/passwd
#sandra

[root@server ]# sh /root/asas
Sandra is in /etc/passwd
variable ha is #sandra

[root@server ]# grep sandra /etc/passwd  --> sandra removed from /etc/passwd

[root@server ]# sh /root/asas
Sandra is in /etc/passwd  --> supposed to be "Sandra is NOT in /etc/passwd"
variable ha is

anil510

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LEARN ABOUT NETBSD

rpc.yppasswdd

RPC.YPPASSWDD(8)					    BSD System Manager's Manual 					  RPC.YPPASSWDD(8)

NAME

     rpc.yppasswdd -- NIS update password file daemon

SYNOPSIS

     rpc.yppasswdd [-d directory] [-noshell] [-nogecos] [-nopw] [-m arg1 [arg2 ...]]

DESCRIPTION

     rpc.yppasswdd must be running on the NIS master server to allow users to change information in the password file.

     The options are as follows:

	   -d directory    Change the root directory of the password file from ``/'' to directory.  It is important to create the binary database
			   files (pwd.db and spwd.db) when using this switch or the password change will fail.	The databases need to be created
			   only once with the following command:

				 pwd_mkdb -d directory directory/etc/master.passwd

	   -noshell	   Don't allow changes of the shell field in the passwd file.

	   -nogecos	   Don't allow changes of the gecos field in the passwd file.

	   -nopw	   Don't allow changes of the password in the passwd file.

	   -m arg1 [arg2 ...]
			   Additional arguments to pass to make in /var/yp.

FILES

     /etc/passwd
     /etc/master.passwd

SEE ALSO

     chpass(1), passwd(1), hosts_access(5), nis(8), ypbind(8), ypserv(8)

AUTHORS

     Mats O Jansson <moj@stacken.kth.se>

BSD
								 February 26, 2005							       BSD

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