PowerShell parse Json file

Question

I've tried to search but find only one post describing the same method I'm using to parse a JSON so was wondering if there is a better way of doing this.

I wrote a small function to generate a random passowrd and using a Json ACII table to definr which characters will be part of the password, I chose this approach as I want to print out spelling for the password as well.

What I have currently is this:

[string]$asciiJson = @"
[
    {"Index": "1","Number": "33","AsciiCode": "!","Phonetic": "Exclamation point","Type": "Symbol"},
    {"Index": "2","Number": "34","AsciiCode": "\"","Phonetic":"Double quotes","Type": "Symbol"},
    {"Index": "3","Number": "35","AsciiCode": "#","Phonetic": "Hash sign","Type": "Symbol"},
    {"Index": "4","Number": "36","AsciiCode": "$","Phonetic": "Dollar sign","Type": "Symbol"},
    {"Index": "5","Number": "37","AsciiCode": "%","Phonetic": "Percent sign","Type": "Symbol"},
    {"Index": "6","Number": "38","AsciiCode": "&","Phonetic": "Ampersand","Type": "Symbol"},
    {"Index": "7","Number": "39","AsciiCode": "'","Phonetic": "Single quote","Type": "Symbol"},
    {"Index": "8","Number": "40","AsciiCode": "(","Phonetic": "Opening parenthesis","Type": "Symbol"},
    {"Index": "9","Number": "41","AsciiCode": ")","Phonetic": "Closing parenthesis","Type": "Symbol"},
    {"Index": "10","Number": "42","AsciiCode": "*","Phonetic": "Asterisk","Type": "Symbol"},
    {"Index": "11","Number": "43","AsciiCode": "+","Phonetic": "Plus sign","Type": "Symbol"},
    {"Index": "12","Number": "44","AsciiCode": ",","Phonetic": "Comma","Type": "Symbol"},
    {"Index": "13","Number": "45","AsciiCode": "-","Phonetic": "Minus sign -Hyphen","Type": "Symbol"},
    {"Index": "14","Number": "46","AsciiCode": ".","Phonetic": "Period","Type": "Symbol"},
    {"Index": "15","Number": "47","AsciiCode": "/","Phonetic": "Slash","Type": "Symbol"},
    {"Index": "16","Number": "58","AsciiCode": ":","Phonetic": "Colon","Type": "Symbol"},
    {"Index": "17","Number": "59","AsciiCode": ";","Phonetic": "SemiColon","Type": "Symbol"},
    {"Index": "18","Number": "60","AsciiCode": "<","Phonetic": "Less than sign","Type": "Symbol"},
    {"Index": "19","Number": "61","AsciiCode": "=","Phonetic": "Equal sign","Type": "Symbol"},
    {"Index": "20","Number": "62","AsciiCode": ">","Phonetic": "Greater than sign","Type": "Symbol"},
    {"Index": "21","Number": "63","AsciiCode": "?","Phonetic": "Question mark","Type": "Symbol"},
    {"Index": "22","Number": "64","AsciiCode": "@","Phonetic": "At symbol","Type": "Symbol"},
    {"Index": "23","Number": "91","AsciiCode": "[","Phonetic": "Opening bracket","Type": "Symbol"},
    {"Index": "24","Number": "92","AsciiCode": "\\","Phonetic": "Backslash","Type": "Symbol"},
    {"Index": "25","Number": "93","AsciiCode": "]","Phonetic": "Closing bracket","Type": "Symbol"},
    {"Index": "26","Number": "94","AsciiCode": "^","Phonetic": "Caret - circumflex","Type": "Symbol"},
    {"Index": "27","Number": "95","AsciiCode": "_","Phonetic": "Underscore","Type": "Symbol"},
    {"Index": "29","Number": "123","AsciiCode": "{","Phonetic": "Opening brace","Type": "Symbol"},
    {"Index": "30","Number": "124","AsciiCode": "|","Phonetic": "Vertical bar","Type": "Symbol"},
    {"Index": "31","Number": "125","AsciiCode": "}","Phonetic": "Closing brace","Type": "Symbol"},
    {"Index": "33","Number": "65","AsciiCode": "A","Phonetic": "Alpha ","Type": "Capital Letter"},
    {"Index": "34","Number": "66","AsciiCode": "B","Phonetic": "Bravo ","Type": "Capital Letter"},
    {"Index": "35","Number": "67","AsciiCode": "C","Phonetic": "Charlie ","Type": "Capital Letter"},
    {"Index": "36","Number": "68","AsciiCode": "D","Phonetic": "Delta ","Type": "Capital Letter"},
    {"Index": "37","Number": "69","AsciiCode": "E","Phonetic": "Echo ","Type": "Capital Letter"},
    {"Index": "38","Number": "70","AsciiCode": "F","Phonetic": "Foxtrot ","Type": "Capital Letter"},
    {"Index": "39","Number": "71","AsciiCode": "G","Phonetic": "Golf ","Type": "Capital Letter"},
    {"Index": "40","Number": "72","AsciiCode": "H","Phonetic": "Hotel ","Type": "Capital Letter"},
    {"Index": "41","Number": "73","AsciiCode": "I","Phonetic": "India ","Type": "Capital Letter"},
    {"Index": "42","Number": "74","AsciiCode": "J","Phonetic": "Juliet ","Type": "Capital Letter"},
    {"Index": "43","Number": "75","AsciiCode": "K","Phonetic": "Kilo ","Type": "Capital Letter"},
    {"Index": "44","Number": "76","AsciiCode": "L","Phonetic": "Lima ","Type": "Capital Letter"},
    {"Index": "45","Number": "77","AsciiCode": "M","Phonetic": "Mike ","Type": "Capital Letter"},
    {"Index": "46","Number": "78","AsciiCode": "N","Phonetic": "November ","Type": "Capital Letter"},
    {"Index": "47","Number": "79","AsciiCode": "O","Phonetic": "Oscar ","Type": "Capital Letter"},
    {"Index": "48","Number": "80","AsciiCode": "P","Phonetic": "Papa ","Type": "Capital Letter"},
    {"Index": "49","Number": "81","AsciiCode": "Q","Phonetic": "Quebec ","Type": "Capital Letter"},
    {"Index": "50","Number": "82","AsciiCode": "R","Phonetic": "Romeo ","Type": "Capital Letter"},
    {"Index": "51","Number": "83","AsciiCode": "S","Phonetic": "Sierra ","Type": "Capital Letter"},
    {"Index": "52","Number": "84","AsciiCode": "T","Phonetic": "Tango ","Type": "Capital Letter"},
    {"Index": "53","Number": "85","AsciiCode": "U","Phonetic": "Uniform ","Type": "Capital Letter"},
    {"Index": "54","Number": "86","AsciiCode": "V","Phonetic": "Victor ","Type": "Capital Letter"},
    {"Index": "55","Number": "87","AsciiCode": "W","Phonetic": "Whiskey ","Type": "Capital Letter"},
    {"Index": "56","Number": "88","AsciiCode": "X","Phonetic": "X-Ray ","Type": "Capital Letter"},
    {"Index": "57","Number": "89","AsciiCode": "Y","Phonetic": "Yankee ","Type": "Capital Letter"},
    {"Index": "58","Number": "90","AsciiCode": "Z","Phonetic": "Zulu ","Type": "Capital Letter"},
    {"Index": "59","Number": "97","AsciiCode": "a","Phonetic": "Alpha ","Type": "Lowercase Letter"},
    {"Index": "60","Number": "98","AsciiCode": "b","Phonetic": "Bravo ","Type": "Lowercase Letter"},
    {"Index": "61","Number": "99","AsciiCode": "c","Phonetic": "Charlie ","Type": "Lowercase Letter"},
    {"Index": "62","Number": "100","AsciiCode": "d","Phonetic": "Delta ","Type": "Lowercase Letter"},
    {"Index": "63","Number": "101","AsciiCode": "e","Phonetic": "Echo ","Type": "Lowercase Letter"},
    {"Index": "64","Number": "102","AsciiCode": "f","Phonetic": "Foxtrot ","Type": "Lowercase Letter"},
    {"Index": "65","Number": "103","AsciiCode": "g","Phonetic": "Golf ","Type": "Lowercase Letter"},
    {"Index": "66","Number": "104","AsciiCode": "h","Phonetic": "Hotel ","Type": "Lowercase Letter"},
    {"Index": "67","Number": "105","AsciiCode": "i","Phonetic": "India ","Type": "Lowercase Letter"},
    {"Index": "68","Number": "106","AsciiCode": "j","Phonetic": "Juliet ","Type": "Lowercase Letter"},
    {"Index": "69","Number": "107","AsciiCode": "k","Phonetic": "Kilo ","Type": "Lowercase Letter"},
    {"Index": "70","Number": "108","AsciiCode": "l","Phonetic": "Lima ","Type": "Lowercase Letter"},
    {"Index": "71","Number": "109","AsciiCode": "m","Phonetic": "Mike ","Type": "Lowercase Letter"},
    {"Index": "72","Number": "110","AsciiCode": "n","Phonetic": "November ","Type": "Lowercase Letter"},
    {"Index": "73","Number": "111","AsciiCode": "o","Phonetic": "Oscar ","Type": "Lowercase Letter"},
    {"Index": "74","Number": "112","AsciiCode": "p","Phonetic": "Papa ","Type": "Lowercase Letter"},
    {"Index": "75","Number": "113","AsciiCode": "q","Phonetic": "Quebec ","Type": "Lowercase Letter"},
    {"Index": "76","Number": "114","AsciiCode": "r","Phonetic": "Romeo ","Type": "Lowercase Letter"},
    {"Index": "77","Number": "115","AsciiCode": "s","Phonetic": "Sierra ","Type": "Lowercase Letter"},
    {"Index": "78","Number": "116","AsciiCode": "t","Phonetic": "Tango ","Type": "Lowercase Letter"},
    {"Index": "79","Number": "117","AsciiCode": "u","Phonetic": "Uniform ","Type": "Lowercase Letter"},
    {"Index": "80","Number": "118","AsciiCode": "v","Phonetic": "Victor ","Type": "Lowercase Letter"},
    {"Index": "81","Number": "119","AsciiCode": "w","Phonetic": "Whiskey ","Type": "Lowercase Letter"},
    {"Index": "82","Number": "120","AsciiCode": "x","Phonetic": "X-Ray ","Type": "Lowercase Letter"},
    {"Index": "83","Number": "121","AsciiCode": "y","Phonetic": "Yankee ","Type": "Lowercase Letter"},
    {"Index": "84","Number": "122","AsciiCode": "z","Phonetic": "Zulu ","Type": "Lowercase Letter"},
    {"Index": "85","Number": "48","AsciiCode": "0","Phonetic": "Zero","Type": "Number"},
    {"Index": "86","Number": "49","AsciiCode": "1","Phonetic": "One","Type": "Number"},
    {"Index": "87","Number": "50","AsciiCode": "2","Phonetic": "Two","Type": "Number"},
    {"Index": "88","Number": "51","AsciiCode": "3","Phonetic": "Three","Type": "Number"},
    {"Index": "89","Number": "52","AsciiCode": "4","Phonetic": "Four","Type": "Number"},
    {"Index": "90","Number": "53","AsciiCode": "5","Phonetic": "Five","Type": "Number"},
    {"Index": "91","Number": "54","AsciiCode": "6","Phonetic": "Six","Type": "Number"},
    {"Index": "92","Number": "55","AsciiCode": "7","Phonetic": "Seven","Type": "Number"},
    {"Index": "93","Number": "56","AsciiCode": "8","Phonetic": "Eight","Type": "Number"},
    {"Index": "94","Number": "57","AsciiCode": "9","Phonetic": "Nine","Type": "Number"}
]
"@

This is the part where I generate the various characters table

        # Generate characters tables
    $charsTable = ConvertFrom-Json -InputObject $asciiJson
    $symbolsTable = $charsTable | Where-Object { $_.Type -eq 'Symbol' }
    $capitalLettersTable = $charsTable | Where-Object { $_.Type -eq 'Capital Letter' }
    $lowerCaseLettersTable = $charsTable | Where-Object { $_.Type -eq 'Lowercase Letter' }
    $digitsTable = $charsTable | Where-Object { $_.Type -eq 'Number' }

All works nicely just noticed when calling function from achild script the parsing part is rather slow so I was wondering if there is a better way to populate the various character tables.

I will admit I'm rather new to JSON so if there is a better way to do this I would be more than glad to hear it.

All in all I can live with the perfromance hit but if there is a way to optimize code why not.

Thanks in advance for any help/Feedback.

score 1 · Answer 1 · answered Apr 30 '18 at 13:02

Why using JSON (JavaScript) at all and not keeping it in PowerShell Object Notation (PSON) format?

You might easily convert it to an PowerShell expression using the ConvertTo-Expression cmdlet:

PS C:\> $asciiJson | ConvertFrom-Json | ConvertTo-Expression -Expand 1
@(
        [PSCustomObject]@{'AsciiCode' = '!'; 'Index' = '1'; 'Number' = '33'; 'Phonetic' = 'Exclamation point'; 'Type' = 'Symbol'},
        [PSCustomObject]@{'AsciiCode' = '"'; 'Index' = '2'; 'Number' = '34'; 'Phonetic' = 'Double quotes'; 'Type' = 'Symbol'},
        [PSCustomObject]@{'AsciiCode' = '#'; 'Index' = '3'; 'Number' = '35'; 'Phonetic' = 'Hash sign'; 'Type' = 'Symbol'},
        [PSCustomObject]@{'AsciiCode' = '$'; 'Index' = '4'; 'Number' = '36'; 'Phonetic' = 'Dollar sign'; 'Type' = 'Symbol'},
        [PSCustomObject]@{'AsciiCode' = '%'; 'Index' = '5'; 'Number' = '37'; 'Phonetic' = 'Percent sign'; 'Type' = 'Symbol'},
...

Anyway, I think you are reinventing the wheel.
A PowerShell password generator with features different character sets (and excluding specific characters) can be found here: https://stackoverflow.com/a/37275209/1701026

Well just a correction I'm not reinventing but reinvented the wheel :P On a more serious note, I jused Javascript format as I took one Json as exampel and did not both to format it appropriately, I'm used to JS and honestly did not even notice. Thanks for the link as I said what I posted is just a snippet of a larger code base but I will have a look at what you posted. — PsCustomObject, Apr 30 '18 at 13:03

iRon · Answer 2 · 2018-07-11T07:00:05.190

A rather late second answer, but I hadn't finished my project yet...

Readability

You wrote "All in all, I can live with the performance hit but if there is a way to optimize code why not" would suggest that you not looking for improving the performance but more for something that can be easier read. To answer that:
Currently, there are a number of listing formats available with converters that let you import a list of object but each option has its for a source table like this:

JSON objects (using ConvertFrom-JSON) is mainly for complex objects but not handy for a listing objects (same goes for PSON objects, using the ConvertTo-Expression cmdlet I purposed).
You could put your listing in an XMLDocument and parse it using the standard PowerShell [XML] parser. But that isn't also easy to read because it is to verbose for this requirement.
You could also consider using a CSV list (using ConvertFrom-CSV), but that actually only support strings and in most cases the columns do not align which makes it also difficult to read.
In fact it would be nice if you could use the output from a Format-Table but there is no convertor available that can convert this back PowerShell objects, or...

'ConvertFrom-SourceTable' cmdlet

The 'ConvertFrom-SourceTable' cmdlet, I created, can actually convert most Format-Table outputs back to a list of objects. Besides it can handle datatypes other than strings. How? See: ConvertFrom-SourceTable -?.

Taking your $asciiJson list as an example and prettify it a little bit because I presume that you would actually like to handle the Index and Numberas numeric values and maybe even format the ascii number as a hex number. To further show it capabilities I changed the AsciiCode column to a character column using [Char] (shorthand for [Char]Char, or if you wish; [Char]AsciiCode) which actually also supersedes the number column with e.g.: [Int]$AsciiTable[0].Char:

$AsciiTable | Select -Property `
    @{Name='Index'; Expression = {[Int]$_.Index}},
    @{Name='Number'; Expression = {"  0x{0:X2}" -f [Int]$_.Number}},
    @{Name='[Char]'; Expression = {$_.AsciiCode}},
    Phonetic,
    Type | Format-Table

Now simply put the result in a string (or in your case, a here-string as it contains quotes):

$AsciiTable = ConvertFrom-SourceTable @'
Index Number [Char] Phonetic            Type
----- ------ ------ --------            ----
    1   0x21 !      Exclamation point   Symbol
    2   0x22 "      Double quotes       Symbol
    3   0x23 #      Hash sign           Symbol
    4   0x24 $      Dollar sign         Symbol
    5   0x25 %      Percent sign        Symbol
    6   0x26 &      Ampersand           Symbol
    7   0x27 '      Single quote        Symbol
    8   0x28 (      Opening parenthesis Symbol
    9   0x29 )      Closing parenthesis Symbol
   10   0x2A *      Asterisk            Symbol
   11   0x2B +      Plus sign           Symbol
   12   0x2C ,      Comma               Symbol
   13   0x2D -      Minus sign -Hyphen  Symbol
   14   0x2E .      Period              Symbol
   15   0x2F /      Slash               Symbol
   16   0x3A :      Colon               Symbol
   17   0x3B ;      SemiColon           Symbol
   18   0x3C <      Less than sign      Symbol
   19   0x3D =      Equal sign          Symbol
   20   0x3E >      Greater than sign   Symbol
   21   0x3F ?      Question mark       Symbol
   22   0x40 @      At symbol           Symbol
   23   0x5B [      Opening bracket     Symbol
   24   0x5C \      Backslash           Symbol
   25   0x5D ]      Closing bracket     Symbol
   26   0x5E ^      Caret - circumflex  Symbol
   27   0x5F _      Underscore          Symbol
   29   0x7B {      Opening brace       Symbol
   30   0x7C |      Vertical bar        Symbol
   31   0x7D }      Closing brace       Symbol
   33   0x41 A      Alpha               Capital Letter
   34   0x42 B      Bravo               Capital Letter
   35   0x43 C      Charlie             Capital Letter
   36   0x44 D      Delta               Capital Letter
   37   0x45 E      Echo                Capital Letter
   38   0x46 F      Foxtrot             Capital Letter
   39   0x47 G      Golf                Capital Letter
   40   0x48 H      Hotel               Capital Letter
   41   0x49 I      India               Capital Letter
   42   0x4A J      Juliet              Capital Letter
   43   0x4B K      Kilo                Capital Letter
   44   0x4C L      Lima                Capital Letter
   45   0x4D M      Mike                Capital Letter
   46   0x4E N      November            Capital Letter
   47   0x4F O      Oscar               Capital Letter
   48   0x50 P      Papa                Capital Letter
   49   0x51 Q      Quebec              Capital Letter
   50   0x52 R      Romeo               Capital Letter
   51   0x53 S      Sierra              Capital Letter
   52   0x54 T      Tango               Capital Letter
   53   0x55 U      Uniform             Capital Letter
   54   0x56 V      Victor              Capital Letter
   55   0x57 W      Whiskey             Capital Letter
   56   0x58 X      X-Ray               Capital Letter
   57   0x59 Y      Yankee              Capital Letter
   58   0x5A Z      Zulu                Capital Letter
   59   0x61 a      Alpha               Lowercase Letter
   60   0x62 b      Bravo               Lowercase Letter
   61   0x63 c      Charlie             Lowercase Letter
   62   0x64 d      Delta               Lowercase Letter
   63   0x65 e      Echo                Lowercase Letter
   64   0x66 f      Foxtrot             Lowercase Letter
   65   0x67 g      Golf                Lowercase Letter
   66   0x68 h      Hotel               Lowercase Letter
   67   0x69 i      India               Lowercase Letter
   68   0x6A j      Juliet              Lowercase Letter
   69   0x6B k      Kilo                Lowercase Letter
   70   0x6C l      Lima                Lowercase Letter
   71   0x6D m      Mike                Lowercase Letter
   72   0x6E n      November            Lowercase Letter
   73   0x6F o      Oscar               Lowercase Letter
   74   0x70 p      Papa                Lowercase Letter
   75   0x71 q      Quebec              Lowercase Letter
   76   0x72 r      Romeo               Lowercase Letter
   77   0x73 s      Sierra              Lowercase Letter
   78   0x74 t      Tango               Lowercase Letter
   79   0x75 u      Uniform             Lowercase Letter
   80   0x76 v      Victor              Lowercase Letter
   81   0x77 w      Whiskey             Lowercase Letter
   82   0x78 x      X-Ray               Lowercase Letter
   83   0x79 y      Yankee              Lowercase Letter
   84   0x7A z      Zulu                Lowercase Letter
   85   0x30 0      Zero                Number
   86   0x31 1      One                 Number
   87   0x32 2      Two                 Number
   88   0x33 3      Three               Number
   89   0x34 4      Four                Number
   90   0x35 5      Five                Number
   91   0x36 6      Six                 Number
   92   0x37 7      Seven               Number
   93   0x38 8      Eight               Number
   94   0x39 9      Nine                Number
'@

Proving that it works:

PS C:\> $AsciiTable | Where {$_.Type -eq "Number"} | Format-Table

Type   Number Phonetic Index Char
----   ------ -------- ----- ----
Number     48 Zero        85    0
Number     49 One         86    1
Number     50 Two         87    2
Number     51 Three       88    3
Number     52 Four        89    4
Number     53 Five        90    5
Number     54 Six         91    6
Number     55 Seven       92    7
Number     56 Eight       93    8
Number     57 Nine        94    9

_{The ConvertFrom-SourceTable cmdlet is available for download at the PowerShell Gallery and the source code from the GitHub iRon7/ConvertFrom-SourceTable repository.}

PowerShell parse Json file

2 Answers2

Readability

'ConvertFrom-SourceTable' cmdlet