Shell Programming and Scripting

echo `tr "\n" " " <infile` | sed 's/Severity/%%Severity/g' | tr -s "%" "\n"

awk 'NR == 1 { 
  printf "%s", $0 FS
  next
} {
  printf "%s", /^Severity/ ? RS $0 FS : $0
} END {
  print ""
}' filename

awk 'NR == 1 { 
  printf "%s ", $0 
  next 
} { 
  if ($0 ~ /^Severity/)
    printf "%s ",  RS $0
  else
    printf "%s", $0 
} END { 
  print "" 
}' filename

sed '/Severity/i\
aa' filename | sed 's/^aa$//' > filename.temp
nawk 'BEGIN{
FS="\n"
RS=""
}
{
for (i=1;i<=NF;i++)
printf("%s ",$i)
print ""
}' filename.temp
rm filename.temp