Vista - Read a line from a text file, without loading the entire file inmemory

I'm currently updating a function to generate password

function create-password {
$leet = @{e=3;o=0;l=1;a=4;i='!';t=7}
$paddingchars = "abcdefghijklmnopqrstuvwxyz01234567890".ToCharArray
()
$spec = "!@#*-+$%^".ToCharArray()
$rand = new-object System.Random
if ($args[0]) { $word = $args[0] } else { $words = import-csv
dic2.csv
$word = ($words[$rand.Next(0,$words.Count)]).Word }
$outputchars = $word.ToCharArray()
$outputchars | foreach-object { $i=0 }{ $skip = $rand.Next(0,3); if
( $skip -ne 0 -AND $leet.ContainsKey([string]$_) ) { $outputchars[$i]
= [char][string]$leet[[string]$_]}; $i+=1 }
while ($outputchars.Length -lt 8) { $outputchars += $paddingchars
[$rand.Next(0,$paddingchars.Length)]}
$OFS = ""
$originalword = $word
$bef=$spec[$rand.next(0,$spec.length)]
$aft=$spec[$rand.next(0,$spec.length)]
$word = $bef+[string]$outputchars+$aft
"Generated password: $word (based on '$originalword')"
}

On line 6 - $words = import-csv dic2.csv => import my dictionary and
choose a random word.

When dic2.csv contains 1000 or 3000, the loading time is acceptable,
but unfortunately my dic2.csv contains over 170000 words, so the
loading time is over 3/4 seconds which is long

Because I know the size of my dic2.csv, I was wondering if it was
possible to get something like this:

$myword = readline ("dic2.csv",$rand.next(0,170000))

returning a random line from dic2.csv without reading everything

Unless you know the length of each line (or each line has the same length)
then this will be tricky. You can always use Get-Content to stream the file
line-by-line. If you really need random access take a look at the
System.IO.FileStream class. It allows you to open a file and seek to any
position in the file and then read bytes from there. Keep in mind that you
need to know the file's encoding and explicitly translate between bytes and
the file's encoding. If it is ASCII then you can use
[System.Text.Encoding]::ASCII.GetString(byte[] bytes).

This kind of points to a minor deficiency in Get-Content - it is missing an
Offset parameter to allow you specify the offset into the file that you want
to start reading from.

HTH,
Keith

"Personne" <cpdivers@xxxxxx> wrote in message
news:fce0534e-4ffd-4bd8-9486-e795860ff3fe@xxxxxx

> This kind of points to a minor deficiency in Get-Content - it is missing anIt would be great if get-content had a -start [regex] -end [regex]
parameter
Don't you think?

Cheers,
Stuart







On 10 Dec, 23:58, "Keith Hill [MVP]"
<r_keith_h...@xxxxxx_no_spam_I> wrote:

Even more fundamental than that would be to have an -AsString or some such
parameter that would spit out a file's entire contents as a single string.
Obviously this would be a disaster for huge files. However I process lots
of small files where I need to apply a regex across the whole file's
contents (not just a single line). Having to run that through string.concat
(or join-string in PSCX) kind of bites. I guess the problem with adding
too many different parameters is that it could start to get kind of
confusing for the user - although the -start/-stop regex does sound
interesting.

--
Keith

"Kryten" <Kryten68@xxxxxx> wrote in message
news:efa64670-e31f-491f-ac02-7a30dbd9e185@xxxxxx

On Dec 11, 2:49*pm, "Keith Hill [MVP]"
<r_keith_h...@xxxxxx_spam_I> wrote:In that case you should try creating a System.IO.StreamReader object:

function Slurp-File {
param([string]$file_path)
[System.IO.StreamReader]$reader = (gi $file_path).fullname
return $reader.ReadToEnd()
}

Mmm data parsing!

How about Microsoft's IIS's (local or remote)
data parser, Log Parser, that comes with many
input engines, to do what one needs or write
one's own Log Parser input and output engines
(perhaps even within powershell.exe)!

@"
cat
dog
animal
bird
mouse
horse
"@ | out-file dic2.txt -encoding ascii

$rand = new-object System.Random

$totalCount = LogParser.exe "SELECT
COUNT(*) FROM dic2.txt " `
-i textword -q on

$pick = $rand.Next(0,$totalCount)

$word = LogParser.exe "SELECT Text
FROM dic2.txt
WHERE index = $($pick + 1) " `
-i textword -q on

" "
"Word is $word"
" "
"Done!"
" "
Exit

Returns:

Word is cat

Done!

For more help, ask any PowerShell user or MVP or
any IIS user or MVP (where Log Parser comes from,
notice that there is no need to have IIS installed in
order to use Log Parser within the Windows admin's
automation tool, powershell.exe) or just perhaps:

LogParser.exe -h

Have fun data parsing
within powershell.exe!

[System.IO.File]::ReadAllText($path) is easier. :-)

--
Keith

"tojo2000" <tojo2000@xxxxxx> wrote in message
news:44b0c3c1-6da7-4ee2-a091-7b27843882a9@xxxxxx

On Dec 12, 9:00*pm, "Keith Hill [MVP]"
<r_keith_h...@xxxxxx_spam_I> wrote:Sure, if you want to do it the easy way, smartass. :P

I like streamreader because it has the readline() method, so that
tends to be my starting point.