Shell Programming and Scripting

if [ -f $filename ] ...

if [ -f "$filename" ] ...

awk '{ printf substr($NF, 1, length($NF)-1);$NF = "";printf " %s\n",$0 }' $filename | sort -n | awk '{ printf "%s%s;\n",$0,$1 }' | awk '{$1="";sub(/^ +/, "");printf "%s\n",$0}' > $filename.sorted

awk '{ print | "sort -nk" NF }' "$filename" > "$filename.sorted"

awk '{ printf substr($NF, 1, length($NF)-1);$NF = "";printf "\n" }' $filename | sort -n | awk '{ if ($1 == prev) { printf "%d\n",$0;num++ };prev=$1 } END { printf "\n%d duplicates were found...\n",num }'

awk 'END { 
  for (k in _) 
    if (_[k] > 1)
      printf "%d\t-->\t%d\n", k, _[k]
      print (c ? c : 0) " duplicates were found..." 
    }
{ sub(/;$/,""); c = _[$NF]++ ? ++c : c }
' "$filename"

if [ -f $filename ]
  then
    ...
else
  echo -e "\ncan't find file $filename\n"

exists () { 
  [ -f "$1" ] || { 
    printf " ... " >&2
    return 1
    }
}

awk -F\| 'END { for (k in _) print k, _[k] }
NR == FNR { _[$1] = $2; next }
$1 in _ { $2 = _[$1]; delete _[$1] } -3
' OFS=\| file2 file1

open(FH1,"<a");
while(<FH1>){
	@arr=split(" ",$_);
	$hash{$arr[2]}=$_;
}
close(FH1);
open(FH2,"<b");
while(<FH2>){
	@arr=split(" ",$_);
	$hash{$arr[2]}=$_;
}
close(FH1);
for $key (sort {$a<=>$b} keys %hash){
	print $hash{$key};
}

WHINY_USERS=1 awk -F\| 'END {
  for(k in _) print k, _[k]
  }
{ _[$1] = $2 }' OFS=\| file1 file2

perl -F'\|' -ane'
  $x{$F[0]}=$F[1];
  END{print map{$_,"|",$x{$_}}sort keys %x}
  ' file1 file2