Vista - Clear-Content Cmdlet and Processing Lines in Text File

I would like to use PowerShell to remove lines in a Text file that is
formatted with several columns. I would like to remove lines in the file up
to where the column value for Mode equals a particular string value.

Is is possible to do this with Clear-Content?

Thanks.

Let me be a little more specific:
the file header looks like this:
Temp Power Impedance Mode
23 34 345 Initial
...............
..............
34 45 2345 Measure
35 36 4545 Treatment
..............
.............

I would like, if possible, to use Clear-content on each line in this file
where the Mode column != Treatment. Is this possible?

Thanks.

"Eudaimonia" wrote:

No Clear-content removes all of the content in the file

You will have to do a get-content and then check for the values you want to
keep and then write out to a new file
--
Richard Siddaway
Please note that all scripts are supplied "as is" and with no warranty
Blog: http://richardsiddaway.spaces.live.com/
PowerShell User Group: http://www.get-psuguk.org.uk


"Eudaimonia" wrote:

Hi Eudaimonia,

Clear-content cmdlet is designed to clear ALL file content.
It is better to choose the Import-Csv cmdlet and filter out the entries you
don't need, then save the results to a new file with Export-Csv.
You're file is delimited with a space delimiter and Import-Csv gets only
comma seperated files, so you'll need to replace all spaces with a comma.


# read the content of the current file
$temp = Get-Content yourfilePath.csv

# replace spaces with commas and write to a new file
$temp = $temp -replace " ",","
$temp | Out-File newCsvFile.csv -encoding ASCII

# import the new file
$csv = Import-csv newCsvFile.csv

# filter and save to a new csv file
$csv | where {$_.Mode -eq "something"} | export-csv c:\final.csv



-----
Shay Levi
$cript Fanatic
http://scriptolog.blogspot.com
Hebrew weblog: http://blogs.microsoft.co.il/blogs/scriptfanatic

Thanks! This is really useful. My example could be clearer; the formatting
is comma delimited. Also, I now realize that what I am trying to do is
remove all the lines at the beginning of the file up to but NOT including
where the Mode is equal to TREATMENT. So, essentially, for each line where
mode does not equal treatment, delete the line up to the first occurence of
the line where the mode column equals TREATMENT.

The pattern you listed below of $csv | where {$_.Mode..... is like a grep
where it will cast the results to a boolean type (if true, pass the object to
the pipeline, otherwise, don't). What I need is a routine that will end once
it encounters the Mode = TREATMENT, kinda like a while....wend in VB while
the Mode != TREATMENT, delete line. Once it encounters the first TREATMENT,
the routine ends.

Thanks again for the help and sorry for the confusion.

"Shay Levi" wrote:

Here are two options:
1- Since Get-Content returns an array of lines you can remove all lines --except the header-- that do not contain 'Treatment' like this:

$content = @(gc testData.csv)
$lastIndex = $content.length - 1
$targetIndex = @(0..$lastIndex | ? {$content[$_] -match 'Treatment'})[0]
$content[0..0 + $targetIndex..$lastIndex] |
Out-File newData1.csv -Encoding ASCII
ipcsv newData1.csv

2- Set a flag to skip the first objects whose Mode value is not 'Treatment':

$pass = $FALSE
ipcsv testData.csv | % {
if ($_.mode -eq 'Treatment') {$pass = $TRUE}
if ($pass) {$_}
} | epcsv newData2.csv -noType
ipcsv newData2.csv

--
Kiron

Hey Eudaimonia,

I'm sorry, but for once I think the solutions are overly complicated. Or
I just haven't really
understood what it is you're asking for

However, I do think the already posted examples can be simplified a lot:

$a = Get-Content c:\test\treatment.txt | where { $_ -match "treatment" }
| Add-Content -path c:\test\results.txt

It simply reads your file, all lines that has "treatment" in it gets added
to a new file.

Best Regards,
Jacob Saaby Nielsen
mailto:jacob.saaby@xxxxxx

Hey Jacob,

sorry, the line only needs to be this:

Get-Content c:\test\treatment.txt | where { $_ -match "treatment" } | Add-Content
-path c:\test\results.txt

(Without the $a)

Best Regards,
Jacob Saaby Nielsen
mailto:jacob.saaby@xxxxxx

Hi Jacob,

Sorry for not being clearer. Your script does work if all I want is to get
the lines with TREATMENT; what I didn't describe clear enough is the problem
that after the first occurence of TREATMENT in the file, I want to preserve
all of the lines some of which have TREATMENT and some of which have other
string values for the Mode column. What your script does is it takes only
the TREATMENT lines.

Thanks!

"Jacob Saaby Nielsen" wrote:

Hi,

The following will output all lines beginning with the first line containing
the text
Treatment.

$foundit = $false
Get-Content inputfile | Where {$foundit -or ($foundit = $_ -match
'Treatment')}

/Fredrik

"Eudaimonia" wrote: