find a user on the system

Shell Programming and Scripting
1

i am prompting for a name to search.

read user
if [ grep "^$user"   /etc/passwd ]
then

however, i get this error:

please enter a username on the system:
fool
menu_script2.sh: line 123: [: ^fool: binary operator expected
2

Try:

read user
grep "^$user" /etc/passwd > /dev/null 2>&1
if [ $? == "0" ]
then
3

dont work

4 
grep "^$user"   /etc/passwd

alone will print a line from /etc/passwd that matches ^$user. What does that line have to do with logical if test?
You are missing backticks and operator there.

if [ X`grep "^$user" /etc/passwd` != X ] ; then #user found in /etc/passwd
5

thank you mirni