Re: regix in grep or something like this

Uh, here we go again. What did you try after your last post. You
should be able to do this with only the most basic of Ruby knowledge.
This is what "df -h" gives me...

# Filesystem      Size   Used  Avail Capacity  Mounted on
# /dev/disk0s2   465Gi  389Gi   75Gi    84%    /
# devfs          191Ki  191Ki    0Bi   100%    /dev
# map -hosts       0Bi    0Bi    0Bi   100%    /net
# map auto_home    0Bi    0Bi    0Bi   100%    /home
# /dev/disk2s2   1.4Ti  504Gi  893Gi    37%    /Volumes/Backup
# /dev/disk1s6   466Gi  305Gi  161Gi    66%    /Volumes/Spare

def mount_check(drive_path)
	%x{df -h}.split(/\n/).each do |line|
	  if line.split(/\s+/).first == drive_path
	    return true
    end
  end

  return false
end

mount_check("/dev/disk0s2") => true

The only point to note is you must give the full drive path,
/dev/disk0s2, rather than just part of it, such as disk0s2.

Also this solution and your solution has absolutely nothing to do with
regexs at all.

Please at least attempt to learn how to program before posting another question.