UNIX for Dummies Questions & Answers

#!/bin/sh
who | grep $1 > /dev/null

if [ $? = "0" ]
then     
   grep $1 /etc/passwd | cut -f 5, -d :
   echo is logged on
   exit 0
else 
   grep $1 /etc/passwd | cut -f 5, -d :
   echo is not logged on
   exit 0
fi

   grep $1 /etc/passwd | cut -f 5, -d : > $user
   echo $user is logged on

   grep $1 /etc/passwd | cut -f 5, -d : = $user

 user=`grep $1 /etc/passwd|cut -f 5 -d:`
echo $user

#!/bin/sh
who | grep $1 > /dev/null

if [ $? = "0" ]
then
   user=`grep $1 /etc/passwd|cut -f 5 -d:`
   echo $user is logged on
   exit 0
else
   grep $1 /etc/passwd | cut -f 5, -d :
   echo is not logged on
   exit 0
fi

#!/bin/sh
use_msg () {
echo "Usage:  `basename $0` [name]"
}

if [ "$#" -ne "1" ] ; then
        use_msg
        exit 2
fi
name_t=`grep ^${1} /etc/passwd | cut -d: -f5 | cut -d, -f1`
if [ "$name_t" = "" ] ; then
        name="$1"
else
        name="$name_t"
fi
who | grep $1 >/dev/null 2>&1
if [ "$?" = "0" ] ; then
        logg=""
else
        logg="not "
fi
echo "${name} is ${logg}logged in"