Ctc Ctc - 5 months ago 18
Linux Question

BASH syntax error at line 1: `then' unmatched

eval: syntax error at line 1: `then' unexpected


Hi, I am having issues with this particular loop and couldn't find a solution to it, any ideas why?

getent passwd | cut -f1 -d":" | sort -n | uniq -c |\ while read x ; do [ -z "${x}" ] && break set - $x if [ $1 -gt 1 ]; then gids=`getent passwd |\ nawk -F: '($1 == n) { print $3 }' n=$2 | xargs` echo "Duplicate Group Name ($2): ${gids}" fi done

Answer

If you run the code through shellcheck and correct the errors which it shows (except for one problematic warning), the code will become:

getent passwd | cut -f1 -d":" | sort -n | uniq -c |
while read -r x ; do
  [ -z "${x}" ] && break
  set - $x
  if [ "$1" -gt 1 ]; then
    gids=$(getent passwd | nawk -F: '($1 == n) { print $3 }' n="$2" | xargs)
    echo "Duplicate Group Name ($2): ${gids}"
  fi
done

The code still seems to have issues, one of which is that it looks for duplicate user names but the print out claims that it found duplicate group names.

I would suggest replacing the above with:

getent passwd | awk -F: '{c[$1]++; uids[$1]=uids[$1]" "$3} END{for (name in c) if (c[name]>1) printf "Duplicate User Name (%s):%s\n",name, uids[name]}'

How the awk code works

In the output of getent passwd, the user name will be in field 1 and the user ID will be in field 3.

  • c[$1]++; uids[$1]=uids[$1]" "$3

    This counts the number of times that user name $1 occurs and saves the count in array c. It also saves the user ID, $3, associated with each name in array uids.

  • END{for (name in c) if (c[name]>1) printf "Duplicate User Name (%s):%s\n",name, uids[name]}

    After we have finished processing getent's output, this looks for user names for which the count is greater than 1 and prints the info.

Multiline version of suggested code

getent passwd | awk -F: '
    {
        c[$1]++
        uids[$1] = uids[$1] " " $3
    } 

    END{
        for (name in c) 
           if (c[name]>1) 
               printf "Duplicate User Name (%s):%s\n", name, uids[name]
    }'