OK, Powershell may not be the best tool for the job but it's the only one available to me.
I have a bunch of 600K+ row .csv data files. Some of them have delimiter errors e.g. " in the middle of a text field or "" at the start of one. They are too big to edit (even in UltraEdit) and fix manually even if I wanted to which I don't!
Because the double-""-delimeter at the start of some text fields and rogue-"-delimiter in the middle of some text fields, I haven't used a header row to define the columns because these rows appear as if there is an extra column in them due to the extra delimiter.
I need to parse the file looking for "" instead of " at the start of a text-field and also to look for " in the middle of a text field and remove them.
I have managed to write the code to do this (after a fashion) by basically reading the whole file into an array, looping through it and adding output characters to an output array.
What I haven't managed to do is successfully write this output array to a file.
I have read every part of https://learn.microsoft.com/en-us/powershell/module/Microsoft.PowerShell.Utility/out-file?view=powershell-5.1 that seemed relevant. I've also trawled through about 10 similar questions on this site and attempted various code gleaned from them.
The output array prints perfectly to screen using a Write-Host but I can't get the data back into a file for love or money. I have a total of 1.5days Powershell experience so far! All suggestions gratefully received.
Here is my code to read/identify rogue delimiters (not pretty (at all), refer previous explanation of data and available technology constraints):
$ContentToCheck=get-content 'myfile.csv' | foreach { $_.ToCharArray()}
$ContentOutputArray=#()
for ($i = 0; $i -lt $ContentToCheck.count; $i++)
{
if (!($ContentToCheck[$i] -match '"')) {#not a quote
if (!($ContentToCheck[$i] -match ',')) {#not a comma i.e. other char that could be enclosed in ""
if ($ContentToCheck[$i-1] -match '"' ) {#check not rogue " delimiter in previous char allow for start of file exception i>1?
if (!($ContentToCheck[$i-2] -match ',') -and !($ContentToCheck[$i-3] -match '"')){
Write-Host 'Delimiter error' $i
$ContentOutputArray+= ''
}#endif not preceded by ",
}#endif"
else{#previous char not a " so move on
$ContentOutputArray+= $ContentToCheck[$i]
}
}#endifnotacomma
else
{#a comma, include it
$ContentOutputArray+= $ContentToCheck[$i]
}#endacomma
}#endifnotaquote
else
{#a quote so just append it to the output array
$ContentOutputArray+= $ContentToCheck[$i]
}#endaquote
}#endfor
So far so good, if inelegant. if I do a simple
Write-Host $ContentOutputArray
data displays nicely " 6 5 " , " 652 | | 999 " , " 99 " , " " , " 678 | | 1 " ..... furthermore when I check the size of the array (based on a cut-down version of one of the problem files)
$ContentOutputArray.count
I get 2507 character length of array. Happy out. However, then variously using:
$ContentOutputArray | Set-Content 'myfile_FIXED.csv'
creates blank file
$ContentOutputArray | out-file 'myfile_FIXED.csv' -encoding ASCII
creates blank file
$ContentOutputArray | export-csv 'myfile_FIXED.csv'
gives only '#TYPE System.Char' in file
$ContentOutputArray | Export-Csv 'myfile_FIXED.csv' -NoType
gives empty file
$ContentOutputArray >> 'myfile_FIXED.csv'
gives blanks separated by ,
What else can I try to write an array of characters to a flat file? It seems such a basic question but it has me stumped. Thanks for reading.
Convert (or cast) the char array to a string before exporting it.
(New-Object string (,$ContentOutputArray)) |Set-Content myfile_FIXED.csv
Related
I'm trying to automate a process, essentially we receive an error code and line numbers for a file. The script I'm writing needs to get the error code and line numbers, then dive into the file and retrieve the lines.
Everything is working except parsing the error code and line numbers into some sort of useable format so I can loop through them
The format is:
Error code Line number
1234 00232,00233,00787
3333 00444
1111 01232,2132
I've tried
$a = $a -replace "\s+","="
$a|ConvertFrom-StringData
But I'm drawing a blank when it comes to looping through the hashtable and dealing with the occasional CSV values.
I did think of converting the whole thing to a CSV but I'm running up against the edge of my knowledge...
Use a regular expression that matches a space followed by either a digit or an upper case letter, then replace said match with a delimiter and finally parse the resulting string as a CSV document:
# read target file into memory for later extraction
$fileContents = Get-Content C:\path\to\source\file.txt
# define error report, replace with `Get-Content` if data if coming from file too
$errorReport = #'
Error code Line number
1234 00232,00233,00787
3333 00444
1111 01232,2132
'#
# replace the middle space and parse as CSV
$errorMappingList = $errorReport -replace '(?-i) (?=\p{Lu}|\d)', '|' |ConvertFrom-Csv -Delimiter '|'
# go through each entry in the error mapping list
foreach($errorMapping in $errorMappingList){
# go through each line number associated with the error code
foreach($lineNo in $errorMapping.'Line Number' -split ','){
# extract the line from the file contents, output 1 new object per line extracted
[pscustomobject]#{
ErrorCode = $errorMapping.'Error code'
LineNumber = $lineNo
Line = $fileContents[$lineNo - 1]
}
}
}
I have an array $vhdlist with contents similar to the following filenames:
UVHD-S-1-5-21-8746256374-654813465-374012747-4533.vhdx
UVHD-S-1-5-21-8746256374-654813465-374012747-6175.vhdx
UVHD-S-1-5-21-8746256374-654813465-374012747-8147.vhdx
UVHD-template.vhdx
I want to use a regex and be left with an array containing only SID portion of the filenames.
I am using the following:
$sids = foreach ($file in $vhdlist)
{
[regex]::split($file, '^UVHD-(?:([(\d)(\w)-]+)).vhdx$')
}
There are 2 problems with this: in the resulting array there are 3 blank lines for every SID; and the "template" filename matches (the resulting line in the output is just "template"). How can I get an array of SIDs as the output and not include the "template" line?
You seem to want to filter the list down to those filenames that contain an SID. Filtering is done with Where-Object (where for short); you don't need a loop.
An SID could be described as "S- and then a bunch of digits and dashes" for this simple case. That leaves us with ^UVHD-S-[\d-]*\.vhdx$ for the filename.
In combination we get:
$vhdlist | where { $_ -Match "^UVHD-S-[\d-]*\.vhdx$" }
When you don't really have an array of strings, but actually an array of files, use them directly.
dir C:\some\folder | where { $_.Name -Match "^UVHD-S-[\d-]*\.vhdx$" }
Or, possibly you can even make it as simple as:
dir C:\some\folder\UVHD-S-*.vhdx
EDIT
Extracting the SIDs from a list of strings can be thought as a combined transformation (for each element, extract the SID) and filter (remove non-matches) operation.
PowerShell's ForEach-Object cmdlet (foreach for short) works like map() in other languages. It takes every input element and returns a new value. In effect it transforms a list of input elements into output elements. Together with the -replace operator you can extract SIDs this way.
$vhdlist | foreach { $_ -replace ^(?:UVHD-(S-[\d-]*)\.vhdx|.*)$,"`$1" } | where { $_ -gt "" }
The regex back-reference for .NET languages is $1. The $ is a special character in PowerShell strings, so it needs to be escaped, except when there is no ambiguity. The backtick is the PS escape character. You can escape the $ in the regex as well, but there it's not necessary.
As a final step we use where to remove empty strings (i.e. non-matches). Doing it this way around means we only need to apply the regex once, instead of two times when filtering first and replacing second.
PowerShell operators can also work on lists directly. So the above could even be shortened:
$vhdlist -replace "^UVHD-(S-[\d-]*)\.vhdx$","`$1" | where { $_ -gt "" }
The shorter version only works on lists of actual strings or objects that produce the right thing when .ToString() is called on them.
Regex breakdown:
^ # start-of-string anchor
(?: # begin non-capturing group (either...)
UVHD- # 'UVHD-'
( # begin group 1
S-[\d-]* # 'S-' and however many digits and dashes
) # end group 1
\.vhdx # '.vhdx'
| # ...or...
.* # anything else
) # end non-capturing group
$ # end-of-string anchor
I just imported a bunch of pictures, and realized that there's 3 copies of each pictures, but they're named sequentially.
Basically these three files are the same:
P5240901.dng
P5240902.dng
P5240903.dng
And that, for about 1600 pictures.
I was looking into writing a simple PowerShell script (I use Windows) that would look into the directory of these files, and keep 1 file out of three, just looping through a range of files.
I didn't find something that would deal with the 'P' character before my file, and I'm not familiar with PowerShell language.
Any ideas?
Thank you!
Assuming everything in the dir follows the naming convention & is in a set of 3 something like this should work:
$mydir = 'C:\path\to\files'
[int]$idx = 1
get-childitem $mydir|sort-object {$_.Name} |foreach-object{
if ($idx % 3 -ne 1){ #get the modulus
$_ |remove-item
}
$idx++
}
Try the following, which will keep only the 1st file in each group of files whose names are the same except for the last character before the filename extension, assuming that character is a digit (syntax assumes PSv3+):
'P5240901.dng', 'P5240902.dng', 'P5240903.dng', 'A1.dng', 'A2.dng', 'singleton.dng' |
Group-Object { $_ -replace '^(.+)\d\.', '$1' } |
? Count -gt 1 |
% { $_.Group[1..$($_.Group.Count)] }
yields:
P5240902.dng
P5240903.dng
A2.dng
Replace the sample input array with a call to Get-ChildItem -File, and prepend Remove-Item to $_.Group[1..$($_.Group.Count)] to perform actual deletion.
The above command uses a string array with input filenames, but the [System.IO.FileInfo] instances output by Get-ChildItem will effectively act the same in a string context: they will expand to their respective filenames.
The advantage of this solution is that it doesn't rely on input files appearing strictly in groups of 3:
Any group of input files sharing the same name except for a digit before the filename extension that has at least 2 members (and any number beyond that) will have every member but the 1st deleted.
Any other files are left untouched.
Explanation:
Group-Object { $_ -replace '^(.+)\d\.', '$1' }
effectively groups the input files by the portion of the filename they share (but only if they share everything but the last char. before the filename extension, and if that char. is a digit).
? Count -gt 1
only passes on those resulting groups that have at least 2 members.
% { $_.Group[1..$($_.Group.Count)] }
processes each group's files, except the 1st.
Update: Here's a variation prompted by the OP's later comments:
The following, given input filenames such as P5240901.dng, P5240902.dng, ..., P5240910.dng, P5240911.dng, ..., P5240990.dng, P5240991.dng, ..., P5240999.dng, will consider each group of 10 files a group (based on the tens place), and within each group only retain the 1st file:
1..99 | % { "P52409$('{0:00}' -f $_).dng" } |
Group-Object { $_ -replace '^(.+\d)\d\.', '$1' } |
? Count -gt 1 |
% { $_.Group[1..$($_.Group.Count)]}
yields:
# tens place of 0; skips ...01.dng
P5240902.dng
P5240903.dng
... # up to ...09.dng
# tens place of 1; skips ...10.dng
P5240911.dng
P5240912.dng
... # skips ...20.dng, ...30.dng, ...
# tens place of 9; skips ...90.dng
P5240991.dng
P5240992.dng
...
P5240999.dng
In order to only pass the files of interest to the command, replace the sample input array with
Get-ChildItem P52515[0-9][0-9].dng.
I try to write a short script what will count average value for CPU for last XY minutes.
I wrote something like that (just short overview). First part of the script just stored values in tmp file. From this values is count avg value:
$CPU= ........ Add-Content "myfile.txt" "$CPU"
$array=(Get-Content -Path myfile.txt);
$AVG=($array | Measure-Object -Average).average;
Then I set first-in first-out function:
if ($array.length -gt XY) {$array=($array[1..($array.Length-0)])>myfile.txt}.
When this condition is completed next execution write to script "strange" character and not number. Type command report "?" as last character in file instead number so average function don`t know work with it.
It doesn't work for PowerShell version 2. I don't have such issue in version 3.
"FIFO" snippet :
(get-content c:\temp\test.txt) |select -skip 1 | set-content c:\temp\test.txt
I've got the following script that works and I'm trying to rewrite in a more efficient manner. The following lines of code below work and accomplish what I want:
Get-Content "C:\Documents and Settings\a411882\My Documents\Scripts\printserveroutput.txt" | Select-String -SimpleMatch -AllMatches -Pattern "/GPR" | % {
$_.Line -replace '(?:.*)(/GPR)(?:.*)(?<=on\s)(\w+)(?:.*)', '$1,$2'
}
Get-Content "C:\Documents and Settings\a411882\My Documents\Scripts\printserveroutput.txt" | Select-String -SimpleMatch -AllMatches -Pattern "DV6" | % {
$_.Line -replace '(?:.*)(DV6)(?:.*)(?<=on\s)(\w+)(?:.*)', '$1,$2'
}
I repeat the same exact lines of code seven times with slightly altering what I'm looking for. The output that I get is the following, which I'd want (note: this is just a small output):
/GPR,R3556
/GPR,R3556
While this works, I really don't like how cluttered the code is and I decided to try re-writing it in a more effective method. I've re-written the code like this:
$My_Arr = "/GPR", "DV6", "DV7", "RT3", "DEV", "TST", "PRE"
$low = $My_Arr.getlowerbound(0)
$upper = $My_Arr.getupperbound(0)
for ($temp=$low; $temp -le $upper; $temp++){
$Test = $My_Arr[$Temp]
Get-Content "C:\Documents and Settings\a411882\My Documents\Scripts\printserveroutput.txt" | Select-String -SimpleMatch -AllMatches -Pattern $My_Arr[$temp] | % {
$_.Line -replace '(?:.*)($Test)(?:.*)(?<=on\s)(\w+)(?:.*)', '$1,$2'
}
}
The output that this gives me is the following:
10 Document 81, A361058/GPR0000151814_1: owned by A361058 was printed on R3556 via port IP_***.***.***.***. Size in bytes: 53704; pages printed: 2 20130219123105.000000-300
10 Document 80, A361058/GPR0000151802_1: owned by A361058 was printed on R3556 via port IP_***.***.***.***. Size in bytes: 53700; pages printed: 2 20130219123037.000000-300
This is almost correct however the -replace line is where my error is occurring since the code is expecting a string instead of variable when it reaches ($Test). It is posting the entire line of the text file that I'm parsing each time that I find /GPR in this example, rather than the desired output shown above. Would anyone know of a method to fix this line and get the same output as the original code I was using?
EDIT: the output that I'm getting right now with the newer code is also the exact text that is in the .txt file I'm trying to parse through. There's more lines than that in the .txt but for the most part it is identical to that. I'm only concerned with getting the /GPR or any of the other possible strings in the array and then the server name which comes after the word "on" each time.
I'd say this is caused by the simple quotes, which prevent variable expansion.
PS is trying to replace the exact string '(?:.*)($Test)(?:.*)(?<=on\s)(\w+)(?:.*)' without replacing the $test variable by its value.
Try replacing them with quotes, but keep simple quotes on the second string, as follows:
Get-Content "C:\Documents and Settings\a411882\My Documents\Scripts\printserveroutput.txt" | Select-String -SimpleMatch -AllMatches -Pattern $My_Arr[$temp] | % {
$_.Line -replace "(?:.*)($Test)(?:.*)(?<=on\s)(\w+)(?:.*)", '$1,$2'
Does this work on your data?
$file = 'C:\Documents and Settings\a411882\My Documents\Scripts\printserveroutput.txt'
$regex = '(?:.*)(/GPR|DV6|DV7|RT3|DEV|TST|PRE)(?:.*)(?<=on\s)(\w+)(?:.*)'
(Get-Content $file) -match $regex -replace $regex,'$1,$2'