Reading username and password from file - linux

Question

I'm looking at a away of reading the username and password of a file and inputing those to either add user or delete user.
EG: I have a file named 'userlist' with the following content with this format:
user1 pass1
user2 pass2
user3 pass3
What I don't understand completely is how to use BASH script to add these accounts.
What I have so far is this:
if [[ whoami -ne "root" ]]
then
exit
else
echo "wish to add or delete? a/d"
read uArg
echo "enter file name"
read uFile
if [ $uArg = "a" -o $uArg = "A" ]
then
IDK WHAT TO DO HERE.
elif [ $uArg = "d" -o $uArg = "D" ]
then
IDK WHAT TO DO HERE.
fi
fi
Alright, what I don't understand is how to read each word line by line and input the username and password to add a new user or delete an existing user.
The program is ment to read the whole file and add each user with there corrosponding password. If delete is chosen then it deletes each user within the file.
I'm new to BASH so any help would be greatyl appreciated.

Answer 1

awk perfectly feets your needs.
See this example:
$ awk '{print "Hi! my name is " $1 ", and my pass is " $2}' ./userpass.txt
Hi! my name is user1, and my pass is pass1
Hi! my name is user2, and my pass is pass2
Hi! my name is user3, and my pass is pass3
Awk stores usernames in $1 and passwords in $2 (first and second column).
You can use pipelines to execute the strings you get from awk as commands:
$ awk '{print "echo " $1}' ./userpass.txt | /bin/bash
user1
user2
user3

Answer 2

something along the lines of...
if [[ whoami -ne "root" ]]
then
exit
else
echo "wish to add or delete? a/d"
read uArg
echo "enter file name"
read uFile
if [ $uArg = "a" -o $uArg = "A" ]
then
while read user passwd rest
do
if [ ! -z $rest ]; then
echo "Bad data"
else
useradd -m $user
passwd $user <<EOP
$passwd
$passwd
EOP
fi
done < $uFile
elif [ $uArg = "d" -o $uArg = "D" ]
then
while read user passwd rest
do
if [ ! -z $rest ]; then
echo "Bad data"
else
userdel $user
fi
done < $uFile
fi
fi

Answer 3

First comments:
learn and get used to basic commands like grep, sed, echo, and generally with file manipulation, awk is a good choice as well if you want to know bash basics, a lot you will encounter is about file manipulation
the code could use more error testing, it's just a basic skeleton
careful about string and variables, quote them whenever possible, spaces in strings can do a lot of bad
Could be something along these lines:
echo "wish to add or delete? a/d"
read uArg
echo "enter username"
read uName
grep "^$uName " password-file
RET=$?
if [ "$uArg" == "a" -o "$uArg" == "A" ]
then
[ $RET -eq 0 ] && echo "User is already in file"
if [ $RET -ne 0 ]
then
echo "enter password"
read uPass
echo "$uName $uPass" >> password-file
fi
elif [ "$uArg" == "d" -o "$uArg" == "D" ]
then
[ $RET -ne 0 ] && echo "User is not file"
if [ $RET -eq 0 ]
then
sed -i "/^$uName /d" password-file
echo "User deleted"
fi
fi