I'm trying to get the last 8 characters of every line of an array in the pipeline,
I thought this would output the last 8 characters but the output seems to be blank
foreach($line in $Texfile)
{
$line[-8..-1]-join ''
}
There's any number of ways to do this, but I opted to pipe Get-Content to ForEach-Object.
Get-Content -Path <Path\to\file.txt> | ForEach-Object {
$_.Substring($_.Length - 8)
}
In your example, you'd use $Line in place of $_ and not pipe to ForEach-Object, and instead, use the Foreach language construct as you've done.
Foreach ($Line in $TextFile) {
$Line.Substring($Line.Length - 8)
}
Try this:
foreach ($Line in $Texfile) {
$Line.Remove(0, ($Line.Length - 8))
}
That works fine. You misspelled $textfile though, with no "t". Maybe that's why you had no output.
Or (-join on the left side):
'1234567890
1234567890
1234567890' | set-content file
$textfile = cat file
foreach($line in $textfile)
{
-join $line[-8..-1]
}
34567890
34567890
34567890
Related
I have a file called "file123624.TXT" that contains this information:
FKHOGU1100;;;;;;;;;;;;;randomdata;1;0;2;1234
YJKMRI1101;;;;;;;;;;;;;randomdata;1;0;2;1234
FWPCYY1113;GV;randomdata;5;;;;;;;6018;randomdata;GU;;1;0;2;1234
VOBYTM1100;;;;;;;;;;;;;randomdata;1;0;2;1234
ZSOKHW1160;GV;randomdata;53;;;;;;;7353;randomdata;GU;;1;0;2;1234
YCHQHS1123;GV;randomdata;4;;;;;;;5063;randomdata;GU;;1;0;2;1234
YXRCZO1105;GV;randomdata;39;;;;;;;9510;randomdata;GU;;1;0;2;1234
XVDUEM1100;GV;randomdata;14;;;;;;;9901;randomdata;GU;;1;0;2;1234
CHECKSUM;0000008
All i want to do is add an - after the first six characters in the file, except for the last line "CHECKSUM; 0000008"
I have made a small powershell script that almost does the trick:
$file = Get-Content "C:\Users\usr\Desktop\file*.txt"
foreach ($i in $file)
{
if($i -notmatch "CHECKSUM*")
{$I.Insert(6,'-')}
}
This script output the lines i need to be changed, but i cant replace them line for line.
The result i want in the "file123624.txt" after running the script is this:
FKHOGU-1100;;;;;;;;;;;;;randomdata;1;0;2;1234
YJKMRI-1101;;;;;;;;;;;;;randomdata;1;0;2;1234
FWPCYY-1113;GV;randomdata;5;;;;;;;6012;randomdata;GU;;1;0;2;1234
VOBYTM-1100;;;;;;;;;;;;;randomdata;1;0;2;1234
ZSOKHW-1160;GV;randomdata;53;;;;;;;7653;randomdata;GU;;1;0;2;1234
YCHQHS-1123;GV;randomdata;4;;;;;;;5463;randomdata;GU;;1;0;2;1234
YXRCZO-1105;GV;randomdata;39;;;;;;;9210;randomdata;GU;;1;0;2;1234
XVDUEM-1100;GV;randomdata;14;;;;;;;9401;randomdata;GU;;1;0;2;1234
CHECKSUM;0000008
Any solutions or tips on this would be appreciated
You can do the following, which utilizes the Foreach-Object and has a similar structure to your current code.
$file = Get-Content file123624.TXT | Foreach-Object {
if ($_ -notmatch '^CHECKSUM') {
$_.Insert(6,'-')
}
else {
$_
}
}
$file | Set-Content file123624.TXT
I want to do this
read the file
go through each line
if the line matches the pattern, do some changes with that line
save the content to another file
For now I use this script:
$file = [System.IO.File]::ReadLines("C:\path\to\some\file1.txt")
$output = "C:\path\to\some\file2.txt"
ForEach ($line in $file) {
if($line -match 'some_regex_expression') {
$line = $line.replace("some","great")
}
Out-File -append -filepath $output -inputobject $line
}
As you can see, here I write line by line. Is it possible to write the whole file at once ?
Good example is provided here :
(Get-Content c:\temp\test.txt) -replace '\[MYID\]', 'MyValue' | Set-Content c:\temp\test.txt
But my problem is that I have additional IF statement...
So, what could I do to improve my script ?
You could do it like that:
Get-Content -Path "C:\path\to\some\file1.txt" | foreach {
if($_ -match 'some_regex_expression') {
$_.replace("some","great")
}
else {
$_
}
} | Out-File -filepath "C:\path\to\some\file2.txt"
Get-Content reads a file line by line (array of strings) by default so you can just pipe it into a foreach loop, process each line within the loop and pipe the whole output into your file2.txt.
In this case Arrays or Array List(lists are better for large arrays) would be the most elegant solution. Simply add strings in array until ForEach loop ends. After that just flush array to a file.
This is Array List example
$file = [System.IO.File]::ReadLines("C:\path\to\some\file1.txt")
$output = "C:\path\to\some\file2.txt"
$outputData = New-Object System.Collections.ArrayList
ForEach ($line in $file) {
if($line -match 'some_regex_expression') {
$line = $line.replace("some","great")
}
$outputData.Add($line)
}
$outputData |Out-File $output
I think the if statement can be avoided in a lot of cases by using regular expression groups (e.g. (.*) and placeholders (e.g. $1, $2 etc.).
As in your example:
(Get-Content .\File1.txt) -Replace 'some(_regex_expression)', 'great$1' | Set-Content .\File2.txt
And for the good example" where [MYID\] might be somewhere inline:
(Get-Content c:\temp\test.txt) -Replace '^(.*)\[MYID\](.*)$', '$1MyValue$2' | Set-Content c:\temp\test.txt
(see also How to replace first and last part of each line with powershell)
I have a text file 'abc.txt' that contains the below.
hello_1
hello_2
..
..
hello_n
I need to write a script to open the file abc.txt and read each line and store that each line in a variable called $temp. I need to read the line only that starts with 'hello'. What is wrong with the below code?
I have the below Code:
foreach ($line in Get-Content "c:\folder\abc.txt")
{
if($line Select-String -Pattern 'hello')
$temp=$line
}
Try this -
$temp = #()
(Get-Content "c:\folder\abc.txt") | % {$temp += $_ | Select-String -Pattern "hello"}
$temp
The code is getting the content of abc.txt, and for each object checking if the pattern matches hello. If it's a match, then it stores the corresponding value in the array defined as $temp.
OR
You can rephrase your original code like this -
$temp = #()
foreach ($line in Get-Content "c:\folder\abc.txt")
{
if($line | Select-String -Pattern 'hello') {
$temp += line
}
}
In you original code, you are missing a pipeline in the statement if($line Select-String -Pattern 'hello'). And you are missing braces{} to enclose the if statement.
You missing pipeline after $line, and curly braces are missing in the whole scriptblock { and } after the foreach, should be:
foreach ($line in Get-Content "c:\folder\abc.txt")
{
{
if($line | Select-String -Pattern 'hello')
$temp=$line
}
}
Also, I don't know what is your purpose, but if you want $line will not be overwrited each time you should create an array outside of the iterration and fill it each time:
so first is: $line = #() and instead of $temp=$line change to $temp += $line
But then again if all your purpose is to filter the hello string from the text file then this should be enough:
$temp = (Get-Content "c:\folder\abc.txt") -match '^hello'
I have following Input lines in my notepad file.
example 1 :
//UNION TEXT=firststring,FRIEND='ABC,Secondstring,ABAER'
example 2 :
//UNION TEXT=firststring,
// FRIEND='ABC,SecondString,ABAER'
Basically, one line can span over two or three lines. If last character is , then it is treated as continuation character.
In example 1 - Text is in one line.
In example 2 - same Text is in two lines.
In example 1, I can probably write below code. However, I do not know how to do this if 'Input text' spans over two or three lines based on continuation character ,
$result = Get-Content $file.fullName | ? { ($_ -match firststring) -and ($_ -match 'secondstring')}
I think I need a way so that I can search text in multipl lines with '-and' condition. something like that...
Thanks!
You could read the entire content of the file, join the continued lines, and then split the text line-wise:
$text = [System.IO.File]::ReadAllText("C:\path\to\your.txt")
$text -replace ",`r`n", "," -split "`r`n" | ...
# get the full content as one String
$content = Get-Content -Path $file.fullName -Raw
# join continued lines, split content and filter
$content -replace '(?<=,)\s*' -split '\r\n' -match 'firststring.+secondstring'
If file is large and you want to avoid loading entire file into memory you might want to use good old .NET ReadLine:
$reader = [System.IO.File]::OpenText("test.txt")
try {
$sb = New-Object -TypeName "System.Text.StringBuilder";
for(;;) {
$line = $reader.ReadLine()
if ($line -eq $null) { break }
if ($line.EndsWith(','))
{
[void]$sb.Append($line)
}
else
{
[void]$sb.Append($line)
# You have full line at this point.
# Call string match or whatever you find appropriate.
$fullLine = $sb.ToString()
Write-Host $fullLine
[void]$sb.Clear()
}
}
}
finally {
$reader.Close()
}
If file is not large (let's say < 1G) Ansgar Wiechers answer should do the trick.
I need to only search the 1st line and last line in a text file to find a "-" and remove it.
How can I do it?
I tried select-string, but I don't know to find the 1st and last line and only remove "-" from there.
Here is what the text file looks like:
% 01-A247M15 G70
N0001 G30 G17 X-100 Y-100 Z0
N0002 G31 G90 X100 Y100 Z45
N0003 ; --PART NO.: NC-HON.PHX01.COVER-SHOE.DET-1000.050
N0004 ; --TOOL: 8.55 X .3937
N0005 ;
N0006 % 01-A247M15 G70
Something like this?
$1 = Get-Content C:\work\test\01.I
$1 | select-object -index 0, ($1.count-1)
Ok, so after looking at this for a while, I decided there had to be a way to do this with a one liner. Here it is:
(gc "c:\myfile.txt") | % -Begin {$test = (gc "c:\myfile.txt" | select -first 1 -last 1)} -Process {if ( $_ -eq $test[0] -or $_ -eq $test[-1] ) { $_ -replace "-" } else { $_ }} | Set-Content "c:\myfile.txt"
Here is a breakdown of what this is doing:
First, the aliases for those now familiar. I only put them in because the command is long enough as it is, so this helps keep things manageable:
gc means Get-Content
% means Foreach
$_ is for the current pipeline value (this isn't an alias, but I thought I would define it since you said you were new)
Ok, now here is what is happening in this:
(gc "c:\myfile.txt") | --> Gets the content of c:\myfile.txt and sends it down the line
% --> Does a foreach loop (goes through each item in the pipeline individually)
-Begin {$test = (gc "c:\myfile.txt" | select -first 1 -last 1)} --> This is a begin block, it runs everything here before it goes onto the pipeline stuff. It is loading the first and last line of c:\myfile.txt into an array so we can check for first and last items
-Process {if ( $_ -eq $test[0] -or $_ -eq $test[-1] ) --> This runs a check on each item in the pipeline, checking if it's the first or the last item in the file
{ $_ -replace "-" } else { $_ } --> if it's the first or last, it does the replacement, if it's not, it just leaves it alone
| Set-Content "c:\myfile.txt" --> This puts the new values back into the file.
Please see the following sites for more information on each of these items:
Get-Content uses
Get-Content definition
Foreach
The Pipeline
Begin and Process part of the Foreach (this are usually for custom function, but they work in the foreach loop as well)
If ... else statements
Set-Content
So I was thinking about what if you wanted to do this to many files, or wanted to do this often. I decided to make a function that does what you are asking. Here is the function:
function Replace-FirstLast {
[CmdletBinding()]
param(
[Parameter( `
Position=0, `
Mandatory=$true)]
[String]$File,
[Parameter( `
Position=1, `
Mandatory=$true)]
[ValidateNotNull()]
[regex]$Regex,
[Parameter( `
position=2, `
Mandatory=$false)]
[string]$ReplaceWith=""
)
Begin {
$lines = Get-Content $File
} #end begin
Process {
foreach ($line in $lines) {
if ( $line -eq $lines[0] ) {
$lines[0] = $line -replace $Regex,$ReplaceWith
} #end if
if ( $line -eq $lines[-1] ) {
$lines[-1] = $line -replace $Regex,$ReplaceWith
}
} #end foreach
}#End process
end {
$lines | Set-Content $File
}#end end
} #end function
This will create a command called Replace-FirstLast. It would be called like this:
Replace-FirstLast -File "C:\myfiles.txt" -Regex "-" -ReplaceWith "NewText"
The -Replacewith is optional, if it is blank it will just remove (default value of ""). The -Regex is looking for a regular expression to match your command. For information on placing this into your profile check this article
Please note: If you file is very large (several GBs), this isn't the best solution. This would cause the whole file to live in memory, which could potentially cause other issues.
try:
$txt = get-content c:\myfile.txt
$txt[0] = $txt[0] -replace '-'
$txt[$txt.length - 1 ] = $txt[$txt.length - 1 ] -replace '-'
$txt | set-content c:\myfile.txt
You can use the select-object cmdlet to help you with this, since get-content basically spits out a text file as one huge array.
Thus, you can do something like this
get-content "path_to_my_awesome_file" | select -first 1 -last 1
To remove the dash after that, you can use the -Replace switch to find the dash and remove it. This is better than using System.String.Replace(...) method because it can match regex statements and replace whole arrays of strings too!
That would look like:
# gc = Get-Content. The parens tell Powershell to do whatever's inside of it
# then treat it like a variable.
(gc "path_to_my_awesome_file" | select -first 1 -last 1) -Replace '-',''
If your file is very large you might not want to read the whole file to get the last line. gc -Tail will get the last line very quickly for you.
function GetFirstAndLastLine($path){
return New-Object PSObject -Property #{
First = Get-Content $path -TotalCount 1
Last = Get-Content $path -Tail 1
}
}
GetFirstAndLastLine "u_ex150417.log"
I tried this on a 20 gb log file and it returned immediately. Reading the file takes hours.
You will still need to read the file if you want to keep all excising content and you want only to remove from the end. Using the -Tail is a quick way to check if it is there.
I hope it helps.
A cleaner answer to the above:
$Line_number_were_on = 0
$Awesome_file = Get-Content "path_to_ridiculously_excellent_file" | %{
$Line = $_
if ($Line_number_were_on -eq $Awesome_file.Length)
{ $Line -Replace '-','' }
else
{ $Line } ;
$Line_number_were_on++
}
I like one-liners, but I find that readability tends to suffer sometimes when I put terseness over function. If what you're doing is going to be part of a script that other people will be reading/maintaining, readability might be something to consider.
Following Nick's answer: I do need to do this on all text files in the directory tree and this is what I'm using now:
Get-ChildItem -Path "c:\work\test" -Filter *.i | where { !$_.PSIsContainer } | % {
$txt = Get-Content $_.FullName;
$txt[0] = $txt[0] -replace '-';
$txt[$txt.length - 1 ] = $txt[$txt.length - 1 ] -replace '-';
$txt | Set-Content $_.FullName
}
and it looks like it's working well now.
Simple process:
Replace $file.txt with your filename
Get-Content $file_txt | Select-Object -last 1
I was recently searching for comments in the last line of .bat files. It seems to mess up the error code of previous commands. I found this useful for searching for a pattern in the last line of files. Pspath is a hidden property that get-content outputs. If I used select-string, I would lose the filename. *.bat gets passed as -filter for speed.
get-childitem -recurse . *.bat | get-content -tail 1 | where { $_ -match 'rem' } |
select pspath
PSPath
------
Microsoft.PowerShell.Core\FileSystem::C:\users\js\foo\file.bat