Bash shell scripting

[ResidentBiscuit]

Ok not really C++ here, but I have this shell script assignment that I can't get to work. Just takes some input and throws it into some variables right now. Anyway, it has to loop back to the beginning using a while loop if there was a mistake. I can't get the condition to work at all. Just spits out errors everytime.

done=0
while [["$done"!="y"]]
do
    echo "First name: "
    read fname
    echo "Last name: "
    read lname
    echo "Login name: "
    read loginname
    echo "User ID: "
    read userid
    echo "Group ID: "
    read groupid
    echo "Create home dir?[y/n] "
    read homedir

    echo
    echo "Name: $fname $lname"
    echo "Login name: $loginname"
    echo "UID: $userid"
    echo "Group ID: $groupid"
    echo "Want home dir? $homedir"
    echo
    echo "Is this correct?[y/n]"
    read done
done

That while condition has been through every different way to do it that I can find, and I get the same type of message of

[[0!=y]]: not found

every time. No idea what I'm doing and I can't seem to find any documentation on how the condition is supposed to be here for while loops here.

[naraku9333]

Try

#!/bin/bash
done=0

while [[ $done != "y" ]]
do
    echo "First name: "
    read fname
    echo "Last name: "
    read lname
    echo "Login name: "
    read loginname
    echo "User ID: "
    read userid
    echo "Group ID: "
    read groupid
    echo "Create home dir?[y/n] "
    read homedir

    echo
    echo "Name: $fname $lname"
    echo "Login name: $loginname"
    echo "UID: $userid"
    echo "Group ID: $groupid"
    echo "Want home dir? $homedir"
    echo
    echo "Is this correct?[y/n]"
    read done
done

note the space between the brackets.

[ResidentBiscuit]

Wow, I'm not at my machine with linux on it, but does the space really matter?? I saw this nowhere in my searching for answers -_-

[naraku9333]

I'm not experienced in shell scripting but the examples I found searching all had spaces and here http://tldp.org/LDP/abs/html/loops1.html in example 11-14 it states the space is necessary because they are test brackets.

[Aramil of Elixia]

he removed the quotes around the variable bro and actually space shouldnt matter but I dont see why you have two [] sets

[slumpers]

Space does matter, since [[ and ]] are reserved keywords in BASH. [[ is different from single bracket [ in that [ is a system command ( /bin/[ which happens to take a ] as its last arguement ). While [ is almost completely portable, it supports far less in terms of what it can do, you are basically limited to the -eq -ne -lt -le etc type of comparisons, instead of == != < <= etc.

Only the BASH and Korn shell support double brackets.

[ResidentBiscuit]

What do the -eq, etc flags mean? I can assume -eq means equal to, -ne means not equal to, but the other two I don't know and I can't seem to find documentation on it anywhere.

EDIT:
I actually found out why it wasn't working. I was running it as "sh adduser", not "bash adduser" -_-

This is why tutorials suck and documentation is the way to go.

Anywho, my conditional doesn't seem to be checking correctly as if I type in "y" for the done variable, it still continues to loop through.

[slumpers]

It worked fine for me.

censored@censored:~/Desktop/progstuff$ bash whileloop.sh 
First name: 
test
Last name: 
mctest
Login name: 
testm
User ID: 
1
Group ID: 
01
Create home dir?[y/n] 
n

Name: test mctest
Login name: testm
UID: 1
Group ID: 01
Want home dir? n

Is this correct?[y/n]
y
censored@censored:~/Desktop/progstuff$

Try encapsulating $done in { brackets like this:
while [[ ${done} != "y" ]]

Also it wouldn't hurt to see what your done variable is actually holding at the end of the loop for test purposes

echo "\$done = \"${done}\""

Edit: Those are the old fashion comparison tags from sh. -lt is less than, -le is less than or equal to.

There is also -gt, -ge for greater than, -z for null and -n for not null.

http://tldp.org/LDP/abs/html/comparison-ops.html

[ikbendeman]

see 'man bash'

also chmod +x /path/to/script

...better yet, use csh instead of bash.

[Aramil of Elixia]

whats csh

[naraku9333]

http://en.wikipedia.org/wiki/C_shell

[ResidentBiscuit]

I've thought about installing csh to play around with it because it seems fun, but haven't gotten to it yet.

[kbw]

Don't use csh (or rather tcsh) for scripts.
http://www.faqs.org/faqs/unix-faq/shell/csh-whynot/