Question

I have the script listed below that I can’t seem to get the issue worked out of. I’m trying to make an interactive login script for a UNIX class that I’m in. I’m basically building out a command to pass into useradd. The command that I make when passed into the command line (while adding sudo) works as expected, but when I try to run it from my script (which is generating the text that I copy/paste into the command line) it gives me some errors… At this point I’m at a loss for what to try next to resolve the issue.

ERROR:

useradd -m --user-group jaredm2 #command that is attempting to run...
useradd: invalid option -- ' '
Usage: useradd [options] LOGIN
....rest of useradd error text....

SCRIPT:

#!/bin/bash
#Add a new user

FINALCOMMAND="-m"

#import useradd defaults...
. /etc/default/useradd

#Check if running as root
if [ "$(id -u)" != "0" ]; then
    echo "This script must be ran as root"
    exit 1
fi

#Get the new users Name
#echo -n "Please enter the users First and Last Name and press [ENTER]: "
#read Name

#Get the new users username
echo "The username must be 4-20 characters."
echo -n "Please enter the users requested username and press [ENTER]: "
read USERNAME
while [ $(grep -c "^${USERNAME}:" /etc/passwd) -ge 1 ] || [ ${#USERNAME} -le 3 ] || [ ${#USERNAME} -ge 21 ]
do
    echo " "
    echo "Error: Username is in use or invalid.  Please select a different username."
    echo " "
    echo -n "Please enter the users requested username and press [ENTER]: "
    read USERNAME   
done #USERNAME will be valid from this point

#ASK about the default shell now
echo -n "Enter the new shell if you would like one (currently $SHELL) or leave blank for the default and press [ENTER]: "
read tempSHELL
if [ ${#tempSHELL} -ge 1 ]; then
    SHELL="$tempSHELL"
    FINALCOMMAND="$FINALCOMMAND ""-s $SHELL"
fi

#ASK about a different primary group
echo "Would you like to enter a non-default primary user group? Defaults to creating a new group that matches the username"
echo "Enter a new Primary Group or leave blank for the default and press [ENTER]: "
read newPrimaryGroup

if [ ${#newPrimaryGroup} -eq 0 ]; then
    FINALCOMMAND="$FINALCOMMAND --user-group"
else
    if [ $(grep -c "^${newPrimaryGroup}" /etc/group) -ge 1 ]; then
        FINALCOMMAND="$FINALCOMMAND -g $newPrimaryGroup"
    else
        echo "Invalid group specified reverting to default!"
        FINALCOMMAND="$FINALCOMMAND --user-group"
    fi
fi
useradd -m --user-group jaredm2
#ASK about additional groups
echo "Would you like the new user to be a part of any additional groups?  Leave blank if no additional groups are needed or enter additional groups in the format of GROUP1,GROUP2,... (NO SPACES) and press [ENTER]: "
read extraGroups
#remove spaces if the user entered any
extraGroups="${extraGroups//[[:space:]]}"
FINALEXTRAGROUPS=""
IFS=","
for g in $extraGroups
do
    if [ $(grep -c "^${g}" /etc/group) -ge 1 ]; then
        FINALEXTRAGROUPS="$FINALEXTRAGROUPS,$g"
    else
        echo "$g is invalid user will not be added..."
    fi
done
FINALEXTRAGROUPS=$(echo "$FINALEXTRAGROUPS" | tail -c +2)
if [ ${#FINALEXTRAGROUPS} -ge 1 ]; then
    FINALCOMMAND="$FINALCOMMAND -G $FINALEXTRAGROUPS"
fi

#ASK about the home directory
echo "Would you like to enter a new home directory for the user?  Leave blank to use the default of $HOME/$USERNAME or enter your own and press [ENTER]: "
read NEWHOME

if [ ${#NEWHOME} -ge 1 ]; then
    FINALCOMMAND="$FINALCOMMAND -d $NEWHOME"
fi

#ADD the username to the command
FINALCOMMAND=`echo "$FINALCOMMAND $USERNAME" | sed 's/ *$//g' | sed 's/^ *//g'`
echo "useradd $FINALCOMMAND"
#PASSCOMMAND="sudo passwd $USERNAME"
#ADD THE USER
`useradd $FINALCOMMAND`

`passwd $USERNAME`

`chfn $USERNAME`

UPDATE: ADDED DEBUG CONTENT

+ '[' 0 -ge 1 ']'
++ sed 's/^ *//g'
++ sed 's/ *$//g'
++ echo '/usr/sbin/useradd -m -U JaredM'
+ FINALCOMMAND='/usr/sbin/useradd -m -U JaredM'
++ '/usr/sbin/useradd -m -U JaredM'
./addnewuser.sh: line 89: /usr/sbin/useradd -m -U JaredM: No such file or directory

Answer 1

By using arrays you could prevent IFS related errors in the command-line and it’s a lot cleaner. This one’s already tested. I made some clean-ups to the code as well.

#!/bin/bash

#Add a new user

FINALCOMMAND=("-m")

#Import useradd defaults...
. /etc/default/useradd

#Check if running as root
if [ "$(id -u)" != "0" ]; then
    echo "This script must be ran as root"
    exit 1
fi

#Get the new users Name
#echo -n "Please enter the users First and Last Name and press [ENTER]: "
#read Name

#Get the new users username
echo "The username must be 4-20 characters."
echo -n "Please enter the users requested username and press [ENTER]: "
read USERNAME
while [ $(grep -c "^${USERNAME}:" /etc/passwd) -ge 1 ] || [ ${#USERNAME} -le 3 ] || [ ${#USERNAME} -ge 21 ]; do
    echo " "
    echo "Error: Username is in use or invalid.  Please select a different username."
    echo " "
    echo -n "Please enter the users requested username and press [ENTER]: "
    read USERNAME
done #USERNAME will be valid from this point

#ASK about the default shell now
echo -n "Enter the new shell if you would like one (currently $SHELL) or leave blank for the default and press [ENTER]: "
read tempSHELL
if [ ${#tempSHELL} -ge 1 ]; then
    SHELL="$tempSHELL"
    FINALCOMMAND=("${FINALCOMMAND[@]}" "-s" "$SHELL")
fi

#ASK about a different primary group
echo "Would you like to enter a non-default primary user group? Defaults to creating a new group that matches the username"
echo -n "Enter a new Primary Group or leave blank for the default and press [ENTER]: "
read newPrimaryGroup

if [ ${#newPrimaryGroup} -eq 0 ]; then
    FINALCOMMAND=("${FINALCOMMAND[@]}" "--user-group")
else
    if [ $(grep -c "^${newPrimaryGroup}" /etc/group) -ge 1 ]; then
        FINALCOMMAND=("${FINALCOMMAND[@]}" "-g" "$newPrimaryGroup")
    else
        echo "Invalid group specified reverting to default!"
        FINALCOMMAND=("${FINALCOMMAND[@]}" "--user-group")
    fi
fi

#ASK about additional groups
echo -n "Would you like the new user to be a part of any additional groups?  Leave blank if no additional groups are needed or enter additional groups in the format of GROUP1,GROUP2,... (NO SPACES) and press [ENTER]: "
read extraGroups
#remove spaces if the user entered any
extraGroups="${extraGroups//[[:space:]]}"
FINALEXTRAGROUPS=''
IFS=, read -a TEMP <<< "$extraGroups"
for g in "${TEMP[@]}"; do
    if [ $(grep -c "^${g}" /etc/group) -ge 1 ]; then
        FINALEXTRAGROUPS="$FINALEXTRAGROUPS,$g"
    else
        echo "$g is invalid user will not be added..."
    fi
done

if [ ${#FINALEXTRAGROUPS[@]} -ge 1 ]; then
    FINALCOMMAND=("${FINALCOMMAND[@]}" "-G" "${FINALEXTRAGROUPS:1}")
fi


#ASK about the home directory
echo -n "Would you like to enter a new home directory for the user?  Leave blank to use the default of $HOME/$USERNAME or enter your own and press [ENTER]: "
read NEWHOME

if [ ${#NEWHOME} -ge 1 ]; then
    FINALCOMMAND=("${FINALCOMMAND[@]}" "-d" "$NEWHOME")
fi

#ADD the username to the command
FINALCOMMAND=("${FINALCOMMAND[@]}" "$USERNAME")

#PASSCOMMAND="sudo passwd $USERNAME"

#ADD THE USER
echo "useradd ${FINALCOMMAND[@]}"

useradd "${FINALCOMMAND[@]}"

passwd "$USERNAME"

chfn "$USERNAME"

Note: In newer versions of bash you could just use += to append a value to an array e.g. ARRAY+=(“value”)

Also by my additional preferences I would improve the code further this way, but that’s not the best of it yet:

#!/bin/bash

shopt -s extglob

# Check if running as root.
if [[ "$(id -u)" != 0 ]]; then
    echo "This script must be ran as root."
    exit 1
fi

# Initialize useradd command variable.
USERADDCOMMAND=("useradd" "-m")

# Import useradd defaults.
. /etc/default/useradd

# Get the new user's name.
#echo -n "Please enter the users First and Last Name and press [ENTER]: "
#read NAME

# Get the new users username.
echo "The username must be 4-20 characters."
while :; do
    read -p "Please enter the user's requested username and press [ENTER]: " USERNAME
    [[ ${#USERNAME} -ge 4 && ${#USERNAME} -le 20 && $USERNAME == +([[:alpha:]])*([[:alnum:]_-]) ]] || {
        echo "Error: Username is invalid. Please enter a different username."
        continue
    }
    [[ $(grep -c "^${USERNAME}:" /etc/passwd) -ge 1 ]] && {
        echo "Error: Username is in use. Please enter a different username."
        continue
    }
    break
done

# Ask about the default shell.
read -p "Enter the new shell if you would like one (currently $SHELL) or leave blank for the default and press [ENTER]: " SHELL_
if [[ ${#SHELL_} -ge 1 ]]; then
    USERADDCOMMAND=("${USERADDCOMMAND[@]}" "-s" "$SHELL_")
else
    # We use this if we really are to use SHELL specified in $SHELL but it still needs further workarounds like checking if $SHELL is valid. Those could be easily done but it depends if this one's really necessary.
    #USERADDCOMMAND=("${USERADDCOMMAND[@]}" "-s" "$SHELL")
    :
fi

# Ask about a different primary group.
echo "Would you like to enter a non-default primary user group? Defaults to creating a new group that matches the username."
echo -n "Enter a new Primary Group or leave blank for the default and press [ENTER]: "
read NEWPRIMARYGROUP

if [[ ${#NEWPRIMARYGROUP} -eq 0 ]]; then
    USERADDCOMMAND=("${USERADDCOMMAND[@]}" "--user-group")
else
    if [[ $(grep -c "^${NEWPRIMARYGROUP}" /etc/group) -ge 1 ]]; then
        USERADDCOMMAND=("${USERADDCOMMAND[@]}" "-g" "$NEWPRIMARYGROUP")
    else
        echo "Invalid group specified reverting to default!"
        USERADDCOMMAND=("${USERADDCOMMAND[@]}" "--user-group")
    fi
fi

# Ask about additional groups.
echo -n "Would you like the new user to be a part of any additional groups?  Leave blank if no additional groups are needed or enter additional groups in the format of GROUP1,GROUP2,... (NO SPACES) and press [ENTER]: "
read EXTRAGROUPS
# Remove spaces if the user entered any.
EXTRAGROUPS="${EXTRAGROUPS//[[:space:]]}"
FINALEXTRAGROUPS=''
IFS=, read -a TEMP <<< "$EXTRAGROUPS"
for G in "${TEMP[@]}"; do
    if [[ $(grep -c "^${g}" /etc/group) -ge 1 ]]; then
        FINALEXTRAGROUPS="$FINALEXTRAGROUPS,$G"
    else
        echo "$G is an invalid user and will not be added."
    fi
done
if [[ ${#FINALEXTRAGROUPS[@]} -ge 1 ]]; then
    USERADDCOMMAND=("${USERADDCOMMAND[@]}" "-G" "${FINALEXTRAGROUPS:1}")
fi

# Ask about the home directory
read -p "Would you like to enter a new home directory for the user?  Leave blank to use the default of $HOME/$USERNAME or enter your own and press [ENTER]: " NEWHOME
if [[ ${#NEWHOME} -ge 1 ]]; then
    USERADDCOMMAND=("${USERADDCOMMAND[@]}" "-d" "$NEWHOME")
fi

# Add the username to the command
USERADDCOMMAND=("${USERADDCOMMAND[@]}" "$USERNAME")

# Add THE USER
echo "> ${USERADDCOMMAND[*]}"
"${USERADDCOMMAND[@]}"

echo "> passwd $USERNAME"
passwd "$USERNAME"

echo "> chfn $USERNAME"
chfn "$USERNAME"  # -f "$NAME"