UNIX for Dummies Questions & Answers

I need to write a shell script which accepts list of users which can be passed as parameters and also taken from a file.. and need to find weather all users are valid users or not..( check in /etc/passwd)

i wrote..like this..

if [ -z $@ ]
then echo enter file name...
read file
grep -f $file /etc/passwd && echo user valid || echo user invalid
exit
else
grep "$@\>" /etc/passwd && echo user valid || echo user invalid
fi
exit

but it worked fine if user name passed tru command line arguments but not worked while taking from a file

example if user33 is a valid user but user3 is not but if v search for unix3(taken from a file) it shows valid user...

if anyone understood this pleasee help me.....

Use -w option with grep while searching for user.
It will force pattern to match complete word.

Here as grep is searching pattern for user3 which comes in user33, so it is matching there.

- nilesh

use awk to match the user name
awk -F':' '$1 == "$variablename"' /etc/passwd

with the other problem, you are making tons of mistakes, but not even checking how many parameters you have

Advanced Bash-Scripting Guide

you need to chek that,

and if you need to read names form a file, use something like

while read line
do
echo "the var line contains this: $line"
done < /path/to/file

tanq very much

i am very much new to unix tanx for ur response