tiralinha

#!/bin/zsh

usage() {
  echo "*** Tiralinha 1.1"
  echo "-----------------"
  echo "Usage: $0 <line number1> [<line number 2> <line number 3>...] <file1> [<file2> <file3>...]"
}

if [[ $# -eq 0 ]]
then
  usage
  exit 2
fi

if [[ $# -eq 1 ]]
then
  if [[ $1 =~ ^[0-9][0-9]*$ ]]
  then
    linha=$1
    files=~/.ssh/known_hosts
  else
    usage
    echo "First argument (line number) must be a number!"
    exit 3
  fi
else
  [[ $1 =~ ^[0-9][0-9]*$ ]] || {
    usage
    echo "First argument (line number) must be a number!"
    exit 3
  }
  linha=$1
  shift
  while [[ $1 =~ ^[0-9][0-9]*$ ]]
  do
    linha="$linha $1"
    shift
  done

  files="$@"
fi

initexpr="$(echo $linha | sed 's/\(\w\w*\)/a[\1]=y\;/g')"

for arq in $files
do
  [[ -r "$arq" && -w "$arq" ]] || {
    echo "File '$file' is not readable or writable. Aborting."
    exit 4
  }
done

for arq in $files
do
  newfile=$(/bin/mktemp)
#  /bin/sed -n ${linha}'!p' < "$arq" > "$newfile" && /bin/cat "$newfile" > "$arq"
  /usr/bin/awk 'BEGIN {'"$initexpr"'} (!(FNR in a)) {print $0}' < "$arq" > "$newfile" && /bin/cat "$newfile" > "$arq"
  /bin/rm "$newfile"
done