How can I remove the [ character from a text file?
My text file contains lines like this:
[Adminlogin] 172.16.48.131 Wednesday Jan102018 07:05:36
And I would like to remove the [.
When I run this,
$file = "MyFile.txt"
Get-Content $file | Foreach {$_ -replace "[", ""} | Set-Content "Myfile-1.txt"
I get an error
The regular expression pattern [ is not valid
However when I run this to remove the ],
$file = "MyFile.txt"
Get-Content $file | Foreach {$_ -replace "]", ""} | Set-Content "Myfile-1.txt"
It runs with no problem.
[ is a regular expression meta character, so you need to escape it.
The simplest way is to use:
{$ -replace "\[", ""}
Or you can use the [Regex]::Escape($str) method. See blog post PowerShell Tip - Escape Regex MetaCharacters for a more detailed example.
Using:
Foreach {$_ -replace '[', ""}
Should also work.
Related
I know that I can use:
gc c:\FileWithEmptyLines.txt | where {$_ -ne ""} > c:\FileWithNoEmptyLines.txt
to remove empty lines. But How I can remove them with '-replace' ?
I found a nice one liner here >> http://www.pixelchef.net/remove-empty-lines-file-powershell. Just tested it out with several blanks lines including newlines only as well as lines with just spaces, just tabs, and combinations.
(gc file.txt) | ? {$_.trim() -ne "" } | set-content file.txt
See the original for some notes about the code. Nice :)
This piece of code from Randy Skretka is working fine for me, but I had the problem, that I still had a newline at the end of the file.
(gc file.txt) | ? {$_.trim() -ne "" } | set-content file.txt
So I added finally this:
$content = [System.IO.File]::ReadAllText("file.txt")
$content = $content.Trim()
[System.IO.File]::WriteAllText("file.txt", $content)
You can use -match instead -eq if you also want to exclude files that only contain whitespace characters:
#(gc c:\FileWithEmptyLines.txt) -match '\S' | out-file c:\FileWithNoEmptyLines
Not specifically using -replace, but you get the same effect parsing the content using -notmatch and regex.
(get-content 'c:\FileWithEmptyLines.txt') -notmatch '^\s*$' > c:\FileWithNoEmptyLines.txt
To resolve this with RegEx, you need to use the multiline flag (?m):
((Get-Content file.txt -Raw) -replace "(?m)^\s*`r`n",'').trim() | Set-Content file.txt
If you actually want to filter blank lines from a file then you may try this:
(gc $source_file).Trim() | ? {$_.Length -gt 0}
You can't do replacing, you have to replace SOMETHING with SOMETHING, and you neither have both.
This will remove empty lines or lines with only whitespace characters (tabs/spaces).
[IO.File]::ReadAllText("FileWithEmptyLines.txt") -replace '\s+\r\n+', "`r`n" | Out-File "c:\FileWithNoEmptyLines.txt"
(Get-Content c:\FileWithEmptyLines.txt) |
Foreach { $_ -Replace "Old content", " New content" } |
Set-Content c:\FileWithEmptyLines.txt;
file
PS /home/edward/Desktop> Get-Content ./copy.txt
[Desktop Entry]
Name=calibre
Exec=~/Apps/calibre/calibre
Icon=~/Apps/calibre/resources/content-server/calibre.png
Type=Application*
Start by get the content from file and trim the white spaces if any found in each line of the text document. That becomes the object passed to the where-object to go through the array looking at each member of the array with string length greater then 0. That object is passed to replace the content of the file you started with. It would probably be better to make a new file...
Last thing to do is reads back the newly made file's content and see your awesomeness.
(Get-Content ./copy.txt).Trim() | Where-Object{$_.length -gt 0} | Set-Content ./copy.txt
Get-Content ./copy.txt
This removes trailing whitespace and blank lines from file.txt
PS C:\Users\> (gc file.txt) | Foreach {$_.TrimEnd()} | where {$_ -ne ""} | Set-Content file.txt
Get-Content returns immutable array of rows. You can covert this to mutable array and delete neccessary lines by index.Particular indexex you can get with match. After that you can write result to new file with Set-Content. With this approach you can avoid empty lines that powershell replace tool leaves when you try to replace smthing with "". Note that I dont guarantee perfect perfomance. Im not a professional powershell developer))
$fileLines = Get-Content $filePath
$neccessaryLine = Select-String -Path $filePath -Pattern 'something'
if (-Not $neccessaryLine) { exit }
$neccessaryLineIndex = $neccessaryLine.LineNumber - 1
$updatedFileContent = [System.Collections.ArrayList]::new($fileLines)
$updatedFileContent.RemoveAt($neccessaryLineIndex)
$updatedHostsFileContent.RemoveAt($domainInfoLineIndex - 1)
$updatedHostsFileContent | Set-Content $hostsFilePath
Set-Content -Path "File.txt" -Value (get-content -Path "File.txt" | Select-String -Pattern '^\s*$' -NotMatch)
This works for me, originally got the line from here and added Joel's suggested '^\s*$': Using PowerShell to remove lines from a text file if it contains a string
I need to place System.Object[] for some columns in a csv file. I tried 3 different method but none of them are working. System.Object[] is put in by powershell when that object is empty or something.
$file = "c:\output.csv"
(gc $file) -replace "'system.object[]'", ""
[io.file]::readalltext($file).replace("'system.object[]'","")
(Get-Content $file | ForEach-Object { $_ -replace "system.object[]", "" } ) | Set-Content $file
I added following code to the variable that containing System.Object[] on output. and it's seems to be working. and now I dont have to do the replacement at file level.
"Access Code" = (#($AccessCode) | Out-String).Trim()
The bracers and the dot ([, ], .) need all to be escaped. Furthermore remove the double quotation marks, just keep the single ones. Also think about using creplace, in case you want to work case insensitive. So the command would look like this:
(gc $file) -replace 'system\.object\[\]', ''
In case you want to write everything to a new file:
(gc $file) -replace 'system\.object\[\]', ''|out-file "test2.txt" -encoding ASCII
Just use Escape character
(gc $file) -replace 'system.object\[\]', ""
The characters '[' and ']' are used for Regex pattern. You must use Escape
character '\' to tell Powershell that This is a regular chars
I have a log file with ^M embedded throughout. I would like to replace the ^M with a single space.
I have tried variations on this:
(Get-Content C:\temp\send.log) | Foreach-Object {$_ -replace "^M", ' '} | Set-Content C:\temp\send.out
The output file contains a newline where each ^M had been, not at all what I was looking for...
The problem I am trying to solve involves examining the last $cnt lines of the file:
$new = Get-Content $fn | Select-Object -Last $cnt;
$new
When I display $new, the ^M are interpreted as CR/LF.
How can I remove/replace the ^M? Thanks for any pointers....
Sounds like ^M is not being replaced by your -replace method, it's likely the replace method is trying to replace capital letter M at the beginning of the string (^). Upon opening the file, ^M is then being interpreted as a carriage return.
Perhaps try replacing the carriage returns (^M) before displaying the contents:
(Get-Content C:\temp\send.log) |
Foreach-Object {$_ -replace "`r", ' '} |
Set-Content C:\temp\send.out
or
$new = Get-Content $fn | Select-Object -Last $cnt;
$new.replace("`r"," ")
Could this be as simple as escaping the ^ character? If you only need the last $count lines of the file you can use the -Tail parameter on Get-Content. Depending if you need to match ^M as case sensitive you might opt for -creplace instead of -replace.
Get-Content $inputfile -Tail $count | ForEach-Object { $_ -creplace '\^m',' ' } | Set-Content $outputfile
This isn't an answer, but since you asked for a few pointers, this might help set things straight.
Try this:
$new = Get-Content $fn | Select-Object -Last $cnt;
$new
$new.gettype()
$new[0].gettype()
I expect you're going to see that $new is an array of objects, and that $new[0] is a string. I'm going to suggest that $new[0] doesn't contain CR or LF or CRLF or anything like that. And I'm going to suggest that, when you ask for the display of $new in its entirety, what you are getting is each string ($new[0] followed by $new[1] ...) with CRLF inserted as a separator.
If I'm right, replacing CR or CRLF with space isn't going to do you any good at all. It's the CRLFs that are being inserted on output to a file that are preventing you from succeeding.
This is as far as I got towards solving your problem.
I have a situation that I need to remove some words from all text file in a folder.
I know how to do that only in 1 file, but I need to do it automatically for all text files in that folder. I got no idea at all how to do it in powershell.
The name of the files are random.
Please help.
This is the code
$txt = get-content c:\work\test\01.i
$txt[0] = $txt[0] -replace '-'
$txt[$txt.length - 1 ] = $txt[$txt.length - 1 ] -replace '-'
$txt | set-content c:\work\test\01.i
Basicly it jsut removes a "-" from first line and last line, but i need to do this on all files in the folder.
Get-ChildItem c:\yourfolder -Filter *.txt | Foreach-Object{
... your code goes here ...
... you can access the current file name via $_.FullName ...
}
Here is a full working example:
Get-ChildItem c:\yourdirectory -Filter *.txt | Foreach-Object{
(Get-Content $_.FullName) |
Foreach-Object {$_ -replace "what you want to replace", "what to replace it with"} |
Set-Content $_.FullName
}
Now for a quick explanation:
Get-ChildItem with a Filter: gets all items ending in .txt
1st ForEach-Object: will perform the commands within the curly brackets
Get-Content $_.FullName: grabs the name of the .txt file
2nd ForEach-Object: will perform the replacement of text within the file
Set-Content $_.FullName: replaces the original file with the new file containing the changes
Important Note: -replace is working with a regular expression so if your string of text has any special characters
something like this ?
ls c:\temp\*.txt | %{ $newcontent=(gc $_) -replace "test","toto" |sc $_ }
$files = get-item c:\temp\*.txt
foreach ($file in $files){(Get-Content $file) | ForEach-Object {$_ -replace 'ur word','new word'} | Out-File $file}
I hope this helps.
Use Get-Childitem to filter for the files you want to modify. Per response to previous question "Powershell, like Windows, uses the extension of the file to determine the filetype."
Also:
You will replace ALL "-" with "" on the first and last lines, using what your example shows, IF you use this instead:
$txt[0] = $txt[0] -replace '-', ''
$txt[$txt.length - 1 ] = $txt[$txt.length - 1 ] -replace '-', ''
Iam trying to replace following string with PowerShell:
...
("
Intel(R) Network Connections 14.2.100.0
","
14.2.100.0
")
...
The code that I use is:
Get-Content $logfilepath |
Foreach-Object { $_ -replace '`r`n`r`n', 'xx'} |
Set-Content $logfilepath_new
But I have no success, can someone say me, where the error is?
First, you are using single quotes in the replace string -
'`r`n`r`n'
that means they are treated verbatim and not as newline characters, so you have to use -
"`r`n`r`n"
To replace, read the file as string and use the Replace() method
$content=[string] $template= [System.IO.File]::ReadAllText("test.txt")
$content.Replace("`r`n`r`n","xx")
Get-content returns an array of lines, so CRLF is essentially your delimiter. Two CRLF sequences back to back would be interpreted as the end of the currrent line, followed by a null line, so no line (object) should contain '`r`n`r`n'. A multi-line regex replace would probably be a better choice.
as alternate method using PS cmdlets:
Get-Content $logfilepath |
Foreach-Object -Begin { $content="" } -Process { $content += $_ ; $content += "xx" } -End { $content } |
Set-Content $logfilepath_new
I used the following code to replace somestring with newline:
$nl = [System.Environment]::NewLine
$content = $content.Replace( somestring, $nl )