linux bash script cut string after first occurance of a character

Question

I'm trying to get the names of all processes in "screen -list"

Unfortunately I already fail at the loop, because

for PLINE in `screen -list | grep 'tached)'`; do
    echo "$PLINE"
done

outputs

3698.processname
(16/08/12
12:59:37)
(Detached)

but my expected output was

    3698.processname    (16/08/12 12:59:37)    (Detached)

like when directly type screen -list | grep 'tached)' screen -list | grep 'tached)' into the console.

What I was trying to do if this loop would've worked, is using cut -d '.' -f 2 cut -d '.' -f 2 and then cutting off the result string after the first whitespace found. ( Which Im also not quite sure how to do yet, all I know is something with %' ' )

So, I think it's pretty obvious that I have not much of a clue in bash script, thus I'm open for more elegant suggestions to do what Im trying to do.

(Edit) Solution:

for PLINE in `screen -list | grep 'tached)' | awk -F '[ \t\n\v\r.]' '{print $3}'`; do
    echo $PLINE
done

Answer 1

$ awk -F '[ \t\n\v\r.]' '{print $2}' <<< $'3698.processname    (16/08/12 12:59:37)    (Detached)'
processname

But there's no need to pipe grep into awk; just have awk match the regex itself.

Answer 2

If all you want is the name, then let's just grab that instead of the whole line.

# screen -list
There are screens on:
    85384.ttyv3.filer0  (Attached)
    85617.another   (Detached)
    57491.pts-0.filer0  (Dead ???)
Remove dead screens with 'screen -wipe'.
2 Sockets in /tmp/screens/S-root.

# screen -list | awk '/ched/{split($1,a,".");print a[2]}'
ttyv3 another
#   

You want it in a variable? A for loop?

# read names <<<$(screen -list | awk '/ched/{split($1,a,".");print a[2]}')
# echo $names
ttyv3 another
# for name in $names; do echo "name=$name"; done
name=ttyv3
name=another
#

Of course, you can avoid most of this noise with pure bash:

screen -list | while read name status; do
  if [[ $status =~ ched ]]; then
    echo "${name#*.}"
  fi
done

This is probably your best solution, as it doesn't rely on any external tools like awk or grep. It'll be more portable, faster and less resource intensive.