PowerShell, formatting values in another culture - powershell

Is there an easy way in PowerShell to format numbers and the like in another locale? I'm currently writing a few functions to ease SVG generation for me and SVG uses . as a decimal separator, while PowerShell honors my locale settings (de-DE) when converting floating-point numbers to strings.
Is there an easy way to set another locale for a function or so without sticking
.ToString((New-Object Globalization.CultureInfo ""))
after every double variable?
Note: This is about the locale used for formatting, not the format string.
(Side question: Should I use the invariant culture in that case or rather en-US?)
ETA: Well, what I'm trying here is something like the following:
function New-SvgWave([int]$HalfWaves, [double]$Amplitude, [switch]$Upwards) {
"<path d='M0,0q0.5,{0} 1,0{1}v1q-0.5,{2} -1,0{3}z'/>" -f (
$(if ($Upwards) {-$Amplitude} else {$Amplitude}),
("t1,0" * ($HalfWaves - 1)),
$(if ($Upwards -xor ($HalfWaves % 2 -eq 0)) {-$Amplitude} else {$Amplitude}),
("t-1,0" * ($HalfWaves - 1))
)
}
Just a little automation for stuff I tend to write all the time and the double values need to use the decimal point instead of a comma (which they use in my locale).
ETA2: Interesting trivia to add:
PS Home:> $d=1.23
PS Home:> $d
1,23
PS Home:> "$d"
1.23
By putting the variable into a string the set locale doesn't seem to apply, somehow.

While Keith Hill's helpful answer shows you how to change a script's current culture on demand (more modern alternative as of PSv3+ and .NET framework v4.6+:
[cultureinfo]::CurrentCulture = [cultureinfo]::InvariantCulture), there is no need to change the culture, because - as you've discovered in your second update to the question - PowerShell's string interpolation - as opposed to using the -f operator - always uses the invariant rather than the current culture:
In other words:
If you replace 'val: {0}' -f 1.2 with "val: $(1.2)", the number literal 1.2 is not formatted according to the rules of the current culture.
You can verify in the console by running (on a single line; PSv3+, .NET framework v4.6+):
PS> [cultureinfo]::currentculture = 'de-DE'; 'val: {0}' -f 1.2; "val: $(1.2)"
val: 1,2 # -f operator: GERMAN culture applies, where ',' is the decimal mark
val: 1.2 # string interpolation: INVARIANT culture applies, where '.' is the decimal mark.
Note: In PowerShell (Core) 7+, the change to a different culture remains in effect for the remainder of the session (as it arguably should for Windows PowerShell too, but doesn't).
Background:
By design,[1] but perhaps surprisingly, PowerShell applies the invariant rather than the current culture in the following string-related contexts, if the type at hand supports culture-specific conversion to and from strings:
As explained in this in-depth answer, PowerShell explicitly requests culture-invariant processing, if possible - by passing the [cultureinfo]::InvariantCulture instance - in the following scenarios (the stringification PowerShell performs is the equivalent of calling .psobject.ToString([NullString]::Value, [cultureinfo]::InvariantCulture) on a value):
When string-interpolating: if the object's type implements the IFormattable interface.
When casting:
to a string, including implicit conversion when binding to a [string]-typed parameter: if the source type implements the [IFormattable] interface.
from a string: if the target type's static .Parse() method has an overload with an [IFormatProvider]-typed parameter (which is an interface implemented by [cultureinfo]).
When string-comparing (-eq, -lt, -gt) , using a String.Compare() overload that accepts a CultureInfo parameter.
Others?
Note that, separately, custom stringification is applied in casts / implicit stringification for the following .NET types:
Arrays and, more generally, similar list-like collection types that PowerShell enumerates in the pipeline (see the bottom section of this answer for what those types are).
The (stringified) elements of such types are concatenated with spaces (strictly speaking: with the string specified in the rarely used $OFS preference variable); the stringification of the elements is recursively subject to the rules described here.
E.g, [string] (1, 2) yields '1 2'
[pscustomobject]
Such instances result in a hashtable-like string format described in this answer; e.g.:
# -> '#{foo=1; bar=2.2}'; values are formatted with the *invariant* culture
[string] ([pscustomobject] #{ foo = 1; bar = 2.2 })
The fact that calling .ToString() directly on a [pscustomobject] instance does not yield this representation and instead returns the empty string should be considered a bug - see GitHub issue #6163.
Others?
As for the purpose of the invariant culture:
The invariant culture is culture-insensitive; it is associated with the English language but not with any country/region.
[...]
Unlike culture-sensitive data, which is subject to change by user customization or by updates to the .NET Framework or the operating system, invariant culture data is stable over time and across installed cultures and cannot be customized by users. This makes the invariant culture particularly useful for operations that require culture-independent results, such as formatting and parsing operations that persist formatted data, or sorting and ordering operations that require that data be displayed in a fixed order regardless of culture.
Presumably, it is the stability across cultures that motivated PowerShell's designers to consistently use the invariant culture when implicitly converting to and from strings.
For instance, if you hard-code a date string such as '7/21/2017' into a script and later try to convert it to date with a [date] cast, PowerShell's culture-invariant behavior ensures that the script doesn't break even when run while a culture other than US-English is in effect - fortunately, the invariant culture also recognizes ISO 8601-format date and time strings;
e.g., [datetime] '2017-07-21' works too.
On the flip side, if you do want to convert to and from current-culture-appropriate strings, you must do so explicitly.
To summarize:
Converting to strings:
Embedding instances of data types with culture-sensitive-by-default string representations inside "..." yields a culture-invariant representation ([double] or [datetime] are examples of such types).
To get a current-culture representation, call .ToString() explicitly or use -f), the formatting operator (possibly inside "..." via an enclosing $(...)).
Converting from strings:
A direct cast ([<type>] ...) only ever recognizes culture-invariant string representations.
To convert from a current-culture-appropriate string representation (or a specific culture's representation), use the target type's static ::Parse() method explicitly (optionally with an explicit [cultureinfo] instance to represent a specific culture).
Culture-INVARIANT examples:
string interpolation and casts:
"$(1/10)" and [string] 1/10
both yield string literal 0.1, with decimal mark ., irrespective of the current culture.
Similarly, casts from strings are culture-invariant; e.g., [double] '1.2'
. is always recognized as the decimal mark, irrespective of the current culture.
Another way of putting it: [double] 1.2 is not translated to the culture-sensitive-by-default method overload [double]::Parse('1.2'), but to the culture-invariant [double]::Parse('1.2', [cultureinfo]::InvariantCulture)
string comparison (assume that [cultureinfo]::CurrentCulture='tr-TR' is in effect - Turkish, where i is NOT a lowercase representation of I)
[string]::Equals('i', 'I', 'CurrentCultureIgnoreCase')
$false with the Turkish culture in effect.
'i'.ToUpper() shows that in the Turkish culture the uppercase is İ, not I.
'i' -eq 'I'
is still $true, because the invariant culture is applied.
implicitly the same as: [string]::Equals('i', 'I', 'InvariantCultureIgnoreCase')
Culture-SENSITIVE examples:
The current culture IS respected in the following cases:
With -f, the string-formatting operator (as noted above):
[cultureinfo]::currentculture = 'de-DE'; '{0}' -f 1.2 yields 1,2
Pitfall: Due to operator precedence, any expression as the RHS of -f must be enclosed in (...) in order to be recognized as such:
E.g., '{0}' -f 1/10 is evaluated as if ('{0}' -f 1) / 10 had been specified;
use '{0}' -f (1/10) instead.
Default output to the console:
e.g., [cultureinfo]::CurrentCulture = 'de-DE'; 1.2 yields 1,2
The same applies to output from cmdlets; e.g.,
[cultureinfo]::CurrentCulture = 'de-DE'; Get-Date '2017-01-01' yields
Sonntag, 1. Januar 2017 00:00:00
Caveat: In certain scenarios, literals passed to a script block as unconstrained parameters can result in culture-invariant default output - see GitHub issue #4557 and GitHub issue #4558.
In (all?) cmdlets:
Those that that perform equality comparisons:
Select-Object with the -Unique switch; also note that - unusually - case-sensitive comparison is performed, and as of PowerShell 7.2.4 case-insensitivity isn't even available as an opt-in - see GitHub issue #12059.
Select-Object
Compare-Object
Others?
Those that write to files:
Set-Content and Add-Content
Out-File and therefore its virtual alias, > (and >>)
e.g., [cultureinfo]::CurrentCulture = 'de-DE'; 1.2 > tmp.txt; Get-Content tmp.txt yields 1,2
Due to .NET's logic, when using the static ::Parse() / ::TryParse() methods on number types such as [double] while passing only the string to parse; e.g., with culture fr-FR in effect (where , is the decimal mark), [double]::Parse('1,2') returns double 1.2 (i.e., 1 + 2/10).
Caveat: As bviktor points out, thousands separators are recognized by default, but in a very loose fashion: effectively, the thousands separator can be placed anywhere inside the integer portion, irrespective of how many digits are in the resulting groups, and a leading 0 is also accepted; e.g., in the en-US culture (where , is the thousands separator), [double]::Parse('0,18') perhaps surprisingly succeeds and yields 18.
To suppress recognition of thousands separators, use something like [double]::Parse('0,18', 'Float'), via the NumberStyles parameter
Unintentional culture-sensitivity that won't be corrected to preserve backward compatibility:
In parameter-binding type conversions for compiled cmdlets (but PowerShell code - scripts or functions - is culture-invariant) - see GitHub issue #6989.
In the -as operator - see GitHub issue #8129.
In [hashtable] key lookups - see this answer and GitHub issue #8280.
[Fixed in v7.1+] In the LHS of -replace operations - see GitHub issue #10948.
Others?
[1] The aim is to support programmatic processing using representations that do not vary by culture and do not change over time. See the linked quote from the docs later in the answer.

This is a PowerShell function I use for testing script in other cultures. I believe it could be used for what you are after:
function Using-Culture ([System.Globalization.CultureInfo]$culture =(throw "USAGE: Using-Culture -Culture culture -Script {scriptblock}"),
[ScriptBlock]$script=(throw "USAGE: Using-Culture -Culture culture -Script {scriptblock}"))
{
$OldCulture = [System.Threading.Thread]::CurrentThread.CurrentCulture
$OldUICulture = [System.Threading.Thread]::CurrentThread.CurrentUICulture
try {
[System.Threading.Thread]::CurrentThread.CurrentCulture = $culture
[System.Threading.Thread]::CurrentThread.CurrentUICulture = $culture
Invoke-Command $script
}
finally {
[System.Threading.Thread]::CurrentThread.CurrentCulture = $OldCulture
[System.Threading.Thread]::CurrentThread.CurrentUICulture = $OldUICulture
}
}
PS> $res = Using-Culture fr-FR { 1.1 }
PS> $res
1.1

I was thinking about how to make it easy and came up with accelerators:
Add-type -typedef #"
using System;
public class InvFloat
{
double _f = 0;
private InvFloat (double f) {
_f = f;
}
private InvFloat(string f) {
_f = Double.Parse(f, System.Globalization.CultureInfo.InvariantCulture);
}
public static implicit operator InvFloat (double f) {
return new InvFloat(f);
}
public static implicit operator double(InvFloat f) {
return f._f;
}
public static explicit operator InvFloat (string f) {
return new InvFloat (f);
}
public override string ToString() {
return _f.ToString(System.Globalization.CultureInfo.InvariantCulture);
}
}
"#
$acce = [type]::gettype("System.Management.Automation.TypeAccelerators")
$acce::Add('f', [InvFloat])
$y = 1.5.ToString()
$z = ([f]1.5).ToString()
I hope it will help.

If you already have the culture loaded in your environment,
#>Get-Culture
LCID Name DisplayName
---- ---- -----------
1031 de-DE German (Germany)
#>Get-UICulture
LCID Name DisplayName
---- ---- -----------
1033 en-US English (United States)
it is possible to resolve this problem:
PS Home:> $d=1.23
PS Home:> $d
1,23
like this:
$d.ToString([cultureinfo]::CurrentUICulture)
1.23
Of course you need to keep in mind that if other users run the script with a different locale setting, the results may not turn out as originally intended.
Nevertheless, this solution could come in useful. Have fun!

Related

Using Sort-Object to sort a Currency/Money

I have a inventory database from my company and I'm wanting to sort some entries based on pricing. I was thinking originally I would have to do everything by hand but I figured Sort-Object should work... until I remembered Sort-Object and its infamous string sorting. Easy, i'll sort by converting it to an integer except of course a currency value has symbol such as $ at the start.
The original code I used which caused the string sorting is below. The classic 200 is higher than 1000 etc:
$Result | Sort-Object -Property Price | Format-Table -Property Price
The int code I tried is:
$Result | Sort-Object -Property { [int]$_.Price } | Format-Table -Property Price
This results in output like "Cannot convert value "$414.50" to type "System.Int32". | Error: "Input string was not in a correct format." Makes sense, cant convert a $ to an int.
So is there any way around this without me having to sort by hand?
Thanks
To add to mclayton's helpful answer:
It is simpler to use a predefined [cultureinfo] instance that uses the your currency format, such as en-US (US-English) in the [decimal]::Parse() call, in combination with C, the currency format specifier.
#(
[pscustomobject] #{ Price='$414.50' },
[pscustomobject] #{ Price='99.02$' }
[pscustomobject] #{ Price='999.03' }
[pscustomobject] #{ Price='$5.04' }
) |
Sort-Object { [decimal]::Parse($_.Price, 'C', [cultureinfo] 'en-US') }
Output (correctly numerically sorted):
Price
-----
$5.04
99.02$
$414.50
999.03
Note:
As the sample input values show, there's some flexibility with respect to what input formats are accepted, such as a trailing $, and a value without $_.
If the current culture can be assumed to be en-US (or a different culture that uses the same currency symbol and formatting, notably also the same decimal separator, .), you can omit the [cultureinfo] 'en-US' argument in the [decimal]::Parse() call above - though for robustness I suggest keeping it.
As an aside: PowerShell's casts (which don't support currency values) always use the invariant culture with string operands, irrespective of the current culture. Thus, something like [decimal] '3.14' is recognized even while a culture that uses , as the decimal separator is in effect.
While the invariant culture - whose purpose is to provide representations that aren't culture-dependent and remain stable over time - is based on the US-English culture, it can not be used here, because its currency symbol is ¤; e.g., (9.99).ToString('C', [cultureinfo]::InvariantCulture) yields ¤9.99.
An input value that cannot be parsed as a currency causes an (effectively) non-terminating error,[1] and such values sort before the currency values.
If you simply want to ignore non-conforming values, use try { [decimal]::Parse(...) } catch { }
If you want to abort processing on encountering non-confirming values pass -ErrorAction Stop to the Sort-Object call.
[1] A .NET method call that fails causes a statement-terminating error, but since the error occurs in a script block (in the context of a calculated property), only the statement inside the script block is terminated, not the enclosing Sort-Object call
Firstly, you probably want [decimal] instead of [int] because [int] "414.50" is 414, not 414.50 so you'll be losing precision.
That aside, I'm adapting this answer for C#: https://stackoverflow.com/a/56603818/3156906
$fi = new-object System.Globalization.NumberFormatInfo;
$fi.CurrencySymbol = "`$";
#("`$10.00", "`$2.00") | Sort-Object -Property #{
"Expression" = { [decimal]::Parse($_, "Currency", $fi) }
};
# $2.00
# $10.00
The advantage of this is that invalid database values like - e.g. $1.$10 - that might have crept in will throw an exception, as will different currencies like £1.00 so you're getting a bit of extra data validation for free.
Note that the results remain as strings, but they're sorted as currency amounts (decimals). If you want the actual numeric value you'll need to convert the values separately...

Powershell String format fails to add hex prefix when looping

Ciao all -
I'm using Powershell 7.2 to automate some hardware configuration through the hardware's CLI.
I am using a loop to generate strings that include "0x" prefixes to express hex bytes, but having an issue where any consecutive iterations after the first pass of the loop do not print the "0x" prefix.
The following will produce the issue:
function fTest($id)
{
foreach($n in #(1, 2, 3))
{
write-host $id.gettype()
write-host ("{0:x}" -f $id)
$id++
}
}
fTest 0x1a
Actual output:
System.Int32
0x1a
System.Int32
1b
System.Int32
1c
The 0xprefixes are omitted in iters 2 and 3.
Why is this happening?
What is a clean way to correct the issue?
I'm a PowerShell noob, so I am happy to receive suggestions or examples of entirely different approaches.
Thanks in advance for the help!
tl;dr
Type-constrain your $p parameter to unambiguously make it a number (integer), as Theo suggests:
function fTest($id) -> function fTest([int] $id)
Build the 0x prefix into the format string passed to -f:
"{0:x}" -f $id -> '0x{0:x}' -f $id
Building on the helpful comments:
Why is this happening?
Format string {0:x}, when applied to a number, only ever produces a hexadecimal representation without a 0x prefix; e.g.:
PS> '{0:x}' -f 10
a # NOT '0xa'
If the operand is not a number, the numeric :x specification is ignored:
PS> '{0:x}' -f 'foo'
foo
The problem in your case is related to how PowerShell handles arguments passed to parameters that are not type-constrained:
Argument 0x1a is ambiguous: it could be a number - expressed as hexadecimal constant 0x1a, equivalent to decimal 26 - or a string.
While in expression-parsing mode this ambiguity would not arise (strings must be quoted there), it does in argument-parsing mode, where quoting around strings is optional (except if the string contains metacharacters) - see the conceptual about_Parsing topic.
What PowerShell does in this case is to create a hybrid argument value: The value is parsed as a number, but it caches its original string representation behind the scenes, which is used for display formatting, for instance:
PS> & { param($p) $p; $p.ToString() } 0x1a
0x1a # With default output formatting, the original string form is used.
26 # $p is an [int], so .ToString() yields its decimal representation
As of PowerShell 7.2.2, surprisingly and problematically, in the context of -f, the string-formatting operator, such a hybrid value is treated as a string, even though it self-reports as a number:
PS> & { param($p) $p.GetType().FullName; '{0:N2}' -f $p } 0x1a
System.Int32 # $p is of type [int] == System.Int32
0x1a # !! With -f $p is unexpectedly treated *as a string*,
# !! yielding the cached original string representation.
This unexpected behavior has been reported in GitHub issue #17199.
Type-constraining the parameter to which such a hybrid argument is passed, as shown at the top, avoids the ambiguity: on invocation, the argument is converted to an unwrapped instance of the parameter's type (see next point).
As for why the output changed starting with the 2nd iteration:
The cached string representation is implemented by way of an invisible [psobject] wrapper around the instance of the numeric type stored in $id, in this case.
When you update this value by way of an increment operation (++), the [psobject] wrapper is lost, and the variable is updated with an unwrapped number (the original value + 1).
Therefore, starting with the 2nd iteration, $id contained an unwrapped [int] instance, resulting in the {0:x} number format being honored and therefore yielding a hexadecimal representation without a 0x prefix.
The only reason the 1st iteration yielded a 0x prefix was that it was present in the original string representation of the argument; as stated above, the numeric :x format specifier was ignored in this case, given that the -f operand was (unexpectedly) treated as a string.

Powershell string interpolation of date value is in incorrect locale [duplicate]

Is there an easy way in PowerShell to format numbers and the like in another locale? I'm currently writing a few functions to ease SVG generation for me and SVG uses . as a decimal separator, while PowerShell honors my locale settings (de-DE) when converting floating-point numbers to strings.
Is there an easy way to set another locale for a function or so without sticking
.ToString((New-Object Globalization.CultureInfo ""))
after every double variable?
Note: This is about the locale used for formatting, not the format string.
(Side question: Should I use the invariant culture in that case or rather en-US?)
ETA: Well, what I'm trying here is something like the following:
function New-SvgWave([int]$HalfWaves, [double]$Amplitude, [switch]$Upwards) {
"<path d='M0,0q0.5,{0} 1,0{1}v1q-0.5,{2} -1,0{3}z'/>" -f (
$(if ($Upwards) {-$Amplitude} else {$Amplitude}),
("t1,0" * ($HalfWaves - 1)),
$(if ($Upwards -xor ($HalfWaves % 2 -eq 0)) {-$Amplitude} else {$Amplitude}),
("t-1,0" * ($HalfWaves - 1))
)
}
Just a little automation for stuff I tend to write all the time and the double values need to use the decimal point instead of a comma (which they use in my locale).
ETA2: Interesting trivia to add:
PS Home:> $d=1.23
PS Home:> $d
1,23
PS Home:> "$d"
1.23
By putting the variable into a string the set locale doesn't seem to apply, somehow.
While Keith Hill's helpful answer shows you how to change a script's current culture on demand (more modern alternative as of PSv3+ and .NET framework v4.6+:
[cultureinfo]::CurrentCulture = [cultureinfo]::InvariantCulture), there is no need to change the culture, because - as you've discovered in your second update to the question - PowerShell's string interpolation - as opposed to using the -f operator - always uses the invariant rather than the current culture:
In other words:
If you replace 'val: {0}' -f 1.2 with "val: $(1.2)", the number literal 1.2 is not formatted according to the rules of the current culture.
You can verify in the console by running (on a single line; PSv3+, .NET framework v4.6+):
PS> [cultureinfo]::currentculture = 'de-DE'; 'val: {0}' -f 1.2; "val: $(1.2)"
val: 1,2 # -f operator: GERMAN culture applies, where ',' is the decimal mark
val: 1.2 # string interpolation: INVARIANT culture applies, where '.' is the decimal mark.
Note: In PowerShell (Core) 7+, the change to a different culture remains in effect for the remainder of the session (as it arguably should for Windows PowerShell too, but doesn't).
Background:
By design,[1] but perhaps surprisingly, PowerShell applies the invariant rather than the current culture in the following string-related contexts, if the type at hand supports culture-specific conversion to and from strings:
As explained in this in-depth answer, PowerShell explicitly requests culture-invariant processing, if possible - by passing the [cultureinfo]::InvariantCulture instance - in the following scenarios (the stringification PowerShell performs is the equivalent of calling .psobject.ToString([NullString]::Value, [cultureinfo]::InvariantCulture) on a value):
When string-interpolating: if the object's type implements the IFormattable interface.
When casting:
to a string, including implicit conversion when binding to a [string]-typed parameter: if the source type implements the [IFormattable] interface.
from a string: if the target type's static .Parse() method has an overload with an [IFormatProvider]-typed parameter (which is an interface implemented by [cultureinfo]).
When string-comparing (-eq, -lt, -gt) , using a String.Compare() overload that accepts a CultureInfo parameter.
Others?
Note that, separately, custom stringification is applied in casts / implicit stringification for the following .NET types:
Arrays and, more generally, similar list-like collection types that PowerShell enumerates in the pipeline (see the bottom section of this answer for what those types are).
The (stringified) elements of such types are concatenated with spaces (strictly speaking: with the string specified in the rarely used $OFS preference variable); the stringification of the elements is recursively subject to the rules described here.
E.g, [string] (1, 2) yields '1 2'
[pscustomobject]
Such instances result in a hashtable-like string format described in this answer; e.g.:
# -> '#{foo=1; bar=2.2}'; values are formatted with the *invariant* culture
[string] ([pscustomobject] #{ foo = 1; bar = 2.2 })
The fact that calling .ToString() directly on a [pscustomobject] instance does not yield this representation and instead returns the empty string should be considered a bug - see GitHub issue #6163.
Others?
As for the purpose of the invariant culture:
The invariant culture is culture-insensitive; it is associated with the English language but not with any country/region.
[...]
Unlike culture-sensitive data, which is subject to change by user customization or by updates to the .NET Framework or the operating system, invariant culture data is stable over time and across installed cultures and cannot be customized by users. This makes the invariant culture particularly useful for operations that require culture-independent results, such as formatting and parsing operations that persist formatted data, or sorting and ordering operations that require that data be displayed in a fixed order regardless of culture.
Presumably, it is the stability across cultures that motivated PowerShell's designers to consistently use the invariant culture when implicitly converting to and from strings.
For instance, if you hard-code a date string such as '7/21/2017' into a script and later try to convert it to date with a [date] cast, PowerShell's culture-invariant behavior ensures that the script doesn't break even when run while a culture other than US-English is in effect - fortunately, the invariant culture also recognizes ISO 8601-format date and time strings;
e.g., [datetime] '2017-07-21' works too.
On the flip side, if you do want to convert to and from current-culture-appropriate strings, you must do so explicitly.
To summarize:
Converting to strings:
Embedding instances of data types with culture-sensitive-by-default string representations inside "..." yields a culture-invariant representation ([double] or [datetime] are examples of such types).
To get a current-culture representation, call .ToString() explicitly or use -f), the formatting operator (possibly inside "..." via an enclosing $(...)).
Converting from strings:
A direct cast ([<type>] ...) only ever recognizes culture-invariant string representations.
To convert from a current-culture-appropriate string representation (or a specific culture's representation), use the target type's static ::Parse() method explicitly (optionally with an explicit [cultureinfo] instance to represent a specific culture).
Culture-INVARIANT examples:
string interpolation and casts:
"$(1/10)" and [string] 1/10
both yield string literal 0.1, with decimal mark ., irrespective of the current culture.
Similarly, casts from strings are culture-invariant; e.g., [double] '1.2'
. is always recognized as the decimal mark, irrespective of the current culture.
Another way of putting it: [double] 1.2 is not translated to the culture-sensitive-by-default method overload [double]::Parse('1.2'), but to the culture-invariant [double]::Parse('1.2', [cultureinfo]::InvariantCulture)
string comparison (assume that [cultureinfo]::CurrentCulture='tr-TR' is in effect - Turkish, where i is NOT a lowercase representation of I)
[string]::Equals('i', 'I', 'CurrentCultureIgnoreCase')
$false with the Turkish culture in effect.
'i'.ToUpper() shows that in the Turkish culture the uppercase is İ, not I.
'i' -eq 'I'
is still $true, because the invariant culture is applied.
implicitly the same as: [string]::Equals('i', 'I', 'InvariantCultureIgnoreCase')
Culture-SENSITIVE examples:
The current culture IS respected in the following cases:
With -f, the string-formatting operator (as noted above):
[cultureinfo]::currentculture = 'de-DE'; '{0}' -f 1.2 yields 1,2
Pitfall: Due to operator precedence, any expression as the RHS of -f must be enclosed in (...) in order to be recognized as such:
E.g., '{0}' -f 1/10 is evaluated as if ('{0}' -f 1) / 10 had been specified;
use '{0}' -f (1/10) instead.
Default output to the console:
e.g., [cultureinfo]::CurrentCulture = 'de-DE'; 1.2 yields 1,2
The same applies to output from cmdlets; e.g.,
[cultureinfo]::CurrentCulture = 'de-DE'; Get-Date '2017-01-01' yields
Sonntag, 1. Januar 2017 00:00:00
Caveat: In certain scenarios, literals passed to a script block as unconstrained parameters can result in culture-invariant default output - see GitHub issue #4557 and GitHub issue #4558.
In (all?) cmdlets:
Those that that perform equality comparisons:
Select-Object with the -Unique switch; also note that - unusually - case-sensitive comparison is performed, and as of PowerShell 7.2.4 case-insensitivity isn't even available as an opt-in - see GitHub issue #12059.
Select-Object
Compare-Object
Others?
Those that write to files:
Set-Content and Add-Content
Out-File and therefore its virtual alias, > (and >>)
e.g., [cultureinfo]::CurrentCulture = 'de-DE'; 1.2 > tmp.txt; Get-Content tmp.txt yields 1,2
Due to .NET's logic, when using the static ::Parse() / ::TryParse() methods on number types such as [double] while passing only the string to parse; e.g., with culture fr-FR in effect (where , is the decimal mark), [double]::Parse('1,2') returns double 1.2 (i.e., 1 + 2/10).
Caveat: As bviktor points out, thousands separators are recognized by default, but in a very loose fashion: effectively, the thousands separator can be placed anywhere inside the integer portion, irrespective of how many digits are in the resulting groups, and a leading 0 is also accepted; e.g., in the en-US culture (where , is the thousands separator), [double]::Parse('0,18') perhaps surprisingly succeeds and yields 18.
To suppress recognition of thousands separators, use something like [double]::Parse('0,18', 'Float'), via the NumberStyles parameter
Unintentional culture-sensitivity that won't be corrected to preserve backward compatibility:
In parameter-binding type conversions for compiled cmdlets (but PowerShell code - scripts or functions - is culture-invariant) - see GitHub issue #6989.
In the -as operator - see GitHub issue #8129.
In [hashtable] key lookups - see this answer and GitHub issue #8280.
[Fixed in v7.1+] In the LHS of -replace operations - see GitHub issue #10948.
Others?
[1] The aim is to support programmatic processing using representations that do not vary by culture and do not change over time. See the linked quote from the docs later in the answer.
This is a PowerShell function I use for testing script in other cultures. I believe it could be used for what you are after:
function Using-Culture ([System.Globalization.CultureInfo]$culture =(throw "USAGE: Using-Culture -Culture culture -Script {scriptblock}"),
[ScriptBlock]$script=(throw "USAGE: Using-Culture -Culture culture -Script {scriptblock}"))
{
$OldCulture = [System.Threading.Thread]::CurrentThread.CurrentCulture
$OldUICulture = [System.Threading.Thread]::CurrentThread.CurrentUICulture
try {
[System.Threading.Thread]::CurrentThread.CurrentCulture = $culture
[System.Threading.Thread]::CurrentThread.CurrentUICulture = $culture
Invoke-Command $script
}
finally {
[System.Threading.Thread]::CurrentThread.CurrentCulture = $OldCulture
[System.Threading.Thread]::CurrentThread.CurrentUICulture = $OldUICulture
}
}
PS> $res = Using-Culture fr-FR { 1.1 }
PS> $res
1.1
I was thinking about how to make it easy and came up with accelerators:
Add-type -typedef #"
using System;
public class InvFloat
{
double _f = 0;
private InvFloat (double f) {
_f = f;
}
private InvFloat(string f) {
_f = Double.Parse(f, System.Globalization.CultureInfo.InvariantCulture);
}
public static implicit operator InvFloat (double f) {
return new InvFloat(f);
}
public static implicit operator double(InvFloat f) {
return f._f;
}
public static explicit operator InvFloat (string f) {
return new InvFloat (f);
}
public override string ToString() {
return _f.ToString(System.Globalization.CultureInfo.InvariantCulture);
}
}
"#
$acce = [type]::gettype("System.Management.Automation.TypeAccelerators")
$acce::Add('f', [InvFloat])
$y = 1.5.ToString()
$z = ([f]1.5).ToString()
I hope it will help.
If you already have the culture loaded in your environment,
#>Get-Culture
LCID Name DisplayName
---- ---- -----------
1031 de-DE German (Germany)
#>Get-UICulture
LCID Name DisplayName
---- ---- -----------
1033 en-US English (United States)
it is possible to resolve this problem:
PS Home:> $d=1.23
PS Home:> $d
1,23
like this:
$d.ToString([cultureinfo]::CurrentUICulture)
1.23
Of course you need to keep in mind that if other users run the script with a different locale setting, the results may not turn out as originally intended.
Nevertheless, this solution could come in useful. Have fun!

DateTime subtraction not working in PowerShell - assignment vs. equality operator

Today (2017-05-29) I am using PowerShell 5.0.10586.117 on Windows 7 Enterprise and run the following (shortened):
$dateOfLicense = "2017-04-20"
$dateOfToday = '{0:yyyy-MM-dd}' -f (Get-Date)
$TimeDifference = [DateTime]$dateOfToday - [DateTime]$dateOfLicense
if (($TimeDifference) = 14)
{
Write-Host "test"
}
Even the difference between both days is 39, my code jumps in the if-clause and sends "test" to screen.
What am I doing wrong here?
You are assigning 14 to $TimeDifference. Instead you wan't to compare the Days property using -le:
if ($TimeDifference.Days -le 14)
{
Write-Host "test"
}
To complement Martin Brandl's helpful answer:
Like many other languages - but unlike VBScript, for instance - PowerShell uses distinct symbols for:
the assignment operator (=)
vs. the equality test operator (-eq).
This distinction enables using assignments as expressions, which is what you inadvertently did:
if ($TimeDifference = 14) ... # same as: if (($TimeDifference) = 14) ...
assigns 14 to variable $TimeDifference, as Martin explains, and, because the assignment is (of necessity, to serve as a conditional for if) enclosed in (...), returns the assigned value (the inner (...) around $TimeDifference make no difference here, however) and that value is used as the Boolean conditional for if.
That is, the (...) expression evaluated by if has value 14 - a nonzero number - and is therefore interpreted as $true in this Boolean context, irrespective of the original value of $TimeDifference.
Note:
To learn more about PowerShell's operators, run Get-Help about_Operators
To learn about how PowerShell interprets arbitrary values as Booleans in conditionals (to-Boolean coercion), see the bottom section of this answer.
To test variables or expressions that already are Booleans, just use them as-is or, if necessary, negate them with -not (!); e.g.:
if ($someBoolean) { # Better than: if ($someBoolean -eq $true)
if (-not $someBoolean) { # Better than: if ($someBoolean -eq $false)
Finally, here's a streamlined version of your code that doesn't require intermediate variables, uses a cast to convert the string to a [datetime] instance and uses [datetime]::now, the more efficient equivalent of Get-Date (though that will rarely matter).
if (([datetime]::now - [datetime] '2017-04-20').Days -eq 14) {
"test"
}
Note how "test" as a statement by itself implicitly sends output to PowerShell's (success) output stream, which prints to the console by default.
Write-Host bypasses this stream and should generally be avoided.
Not better solution of Martin, just an shorty code
$dateOfLicense = [DateTime]"2017-04-20"
$TimeDifferenceDays = ((Get-Date) - $dateOfLicense).Days
if ($TimeDifferenceDays -lt 14)
{
Write-Host "test"
}

Powershell - remove currency formatting from a number

can you please tell me how to remove currency formatting from a variable (which is probably treated as a string).
How do I strip out currency formatting from a variable and convert it to a true number?
Thank you.
example
PS C:\Users\abc> $a=($464.00)
PS C:\Users\abc> "{0:N2}" -f $a
<- returns blank
However
PS C:\Users\abc> $a=-464
PS C:\Users\abc> "{0:C2}" -f $a
($464.00) <- this works
PowerShell, the programming language, does not "know" what money or currency is - everything PowerShell sees is a variable name ($464) and a property reference (.00) that doesn't exist, so $a ends up with no value.
If you have a string in the form: $00.00, what you can do programmatically is:
# Here is my currency amount
$mySalary = '$500.45'
# Remove anything that's not either a dot (`.`), a digit, or parentheses:
$mySalary = $mySalary -replace '[^\d\.\(\)]'
# Check if input string has parentheses around it
if($mySalary -match '^\(.*\)$')
{
# remove the parentheses and add a `-` instead
$mySalary = '-' + $mySalary.Trim('()')
}
So far so good, now we have the string 500.45 (or -500.45 if input was ($500.45)).
Now, there's a couple of things you can do to convert a string to a numerical type.
You could explicitly convert it to a [double] with the Parse() method:
$mySalaryNumber = [double]::Parse($mySalary)
Or you could rely on PowerShell performing an implicit conversion to an appropriate numerical type with a unary +:
$mySalaryNumber = +$mySalary