I have a text file sample.txt containing
computer
computer.pc = 1
pc
i want only number 1, where i want to assign that value to a variable
$number = Get -content "sample.txt"
You can extract the number by using the Regex Match method.
Example code to do this:
$number = ([regex]::Match((Get-content "sample.txt"), "\d+")).Value
The pattern \d+ means to match one or more decimal digits and using the Match method will return the first match found.
See Quantifiers in Regular Expressions for additional information regarding the quantifiers available.
Related
I am using this to find if file name contains exactly 7 digits
if ($file.Name -match '\D(\d{7})(?:\D|$)') {
$result = $matches[1]
}
The problem is when there is a file name that contains 2 groups of 7 digits
for an example:
patch-8.6.22 (1329214-1396826-Increase timeout.zip
In this case the result will be the first one (1329214).
For most cases there is only one number so the regex is working but I must to recognize if there is more than 1 group and integrated into the if ()
The -match operator only ever looks for one match.
To get multiple ones, you must currently use the underlying .NET APIs directly, specifically [regex]::Matches():
Note: There's a green-lighted proposal to implement a -matchall operator, but as of PowerShell 7.3.0 it hasn't been implemented yet - see GitHub issue #7867.
# Sample input.
$file = [pscustomobject] #{ Name = 'patch-8.6.22 (1329214-1396826-Increase timeout.zip' }
# Note:
# * If *nothing* matches, $result will contain $null
# * If *one* substring matches, return will be a single string.
# * If *two or more* substrings match, return will be an *array* of strings.
$result = ([regex]::Matches($file.Name, '(?<=\D)\d{7}(?=\D|$)')).Value
.Value uses member-access enumeration to extract matching substrings, if any, from the elements of the collection returned by [regex]::Matches().
I've tweaked the regex to use lookaround assertions ((?<=/...) and (?=...)) so that only the substrings of interest are captured.
See this regex101.com page for an explanation of the regex and the ability to experiment with it.
Trying to convert the number numeric value in this string to a percent. Is there any easy way to do this in powershell?
"Percentage of records ","0.02"
So, the output would look like :
Percentage of records , 2%
Thanks in advance for any suggestions you can provide.
Yes, you can convert the string to a float data type (single, double, decimal), and then convert it back using a format string, like so:
"Percentage of records ", ([double]'0.02').ToString('P0')
And if you want it to output in a single line, you could use:
"Percentage of records: $(([double]'0.02').ToString('P0'))"
Explanation:
Convert your string to a float datatype: [double]'0.02'
Convert that float back into a string: .ToString()
But we want to format it as a percentage, so we supply P0 as a parameter.
i. P - means to format the value as a percentage, this performs the N * 100 operation for you and then adds on the percent sign
ii. 0 - controls the number of decimal places to show. In your case, you want to show zero decimal places.
Note: The percentage format string will round your value to the nearest decimal that you specify.
Example:
0.021.ToString('P0')
# returns 2%
0.025.ToString('P0')
# returns 3%
As #mklement0 pointed out in the comments. I hadn't considered that your sample may be a single string, like:
'"Percentage of records ","0.02"'
I assumed it was two strings, which you separated with a comma.
In the event it is a single string, then you need to extract the number to use it. Once you have isolated the number, then you can use my advice above:
$yourString = '"Percentage of records ","0.02"'
# probably the more "proper" way
$pctValue = ($yourString -split ',' -replace '"')[1]
# or
# a hacky way I just thought of that happens to work in this scenario
$pctValue = (iex $yourString)[1]
Explanation of first example:
-split ',' - Take the string, and break it out into multiple strings, separating them by comma
-replace '"','' - Replace all instances of " with blank. The second parameter is optional since you are removing. Could be written as -replace '"'
(...)[1] - This is saying to take the SECOND string that it returned (starts at zero). In this case it would be your 0.02 value.
Explanation of second example (this is a bit of a hack, but thought it would be fun to include anyway):
iex - alias for Invoke-Expression - it's telling powershell to run whatever is inside of the string verbatim. So it's the equivalent of typing "Percentage of records ","0.02" into powershell and hitting enter. Which in PowerShell terms, that is the equivalent of passing it a list of strings.
Use -f (format operator) in powerhsell for build your string :
"Percentage of records, {0:0%} " -f 0.02
or in percentage :
"Percentage of records, {0:P0} " -f 0.02
So basically what I'm trying to achieve is to get a MAC address from a text file and increment the value by one.
Been bashing my head against the Google/StackOverflow wall for a couple of hours, think there's a concept I'm just not getting.
PowerShell:
$Last_MAC_Address = (Get-Content -LiteralPath "\\UNC\Path\Last MAC Address.txt")
Write-Host ($Last_MAC_Address)
# Output: 00155DE10B73
$Next_MAC_Address = (($Last_MAC_Address | Format-Hex) + 1)
This is a 3 step process, and although PetSerAl answered it in the comments as a one liner, I'll break it down slightly for posterity (and use a different class).
The first step is to get the Hex number as a decimal (mathematical base 10, not type).
The Second step is the incrementation of the decimal.
And the final step is converting it back to hexadecimal.
broken down and not a one liner this will accomplish the task at hand:
$asDecimal = [System.Convert]::ToInt64("00155DE10B73", 16)
$asDecimal++
$asHex = [System.Convert]::ToString($asDecimal, 16)
Another option is to prefix the value with 0x and cast it to an int64:
$Next_MAC_Address = ([int64]"0x$Last_MAC_Address"+1).ToString('X12')
You could also use the format operator (-f) instead of the ToString() method:
$Next_MAC_Address = '{0:X12}' -f ([int64]"0x$Last_MAC_Address"+1)
There is, however, one thing that may be worth noting. MAC addresses aren't just random 6-byte numbers without any inner structure. They actually consist of two parts. The first 3 bytes form the Organizationally Unique Identifier (OUI), a vendor-specific prefix (00-15-5D is one of the OUIs belonging to Microsoft). Only the last 3 bytes are a random number, a unique identifier for each card from the vendor identified by the OUI.
Taking that into consideration you may want to split the MAC address accordingly, e.g. like this:
$oui, $nid = $Last_MAC_Address -split '(?<=^[0-9a-f]{6})(?=[0-9a-f]{6}$)'
or like this:
$oui = $Last_MAC_Address.Substring(0, 6)
$nid = $Last_MAC_Address.Substring(6, 6)
and increment only the NIC identifier, and only if it wouldn't overflow:
if ($nid -ne 'ffffff') {
$Next_MAC_Address = "{0}{1:X6}" -f $oui, ([int64]"0x$nid"+1)
} else {
Write-Error 'MAC address overflow.'
}
I have a string and I need two characters to be returned.
I tried with strsplit but the delimiter must be a string and I don't have any delimiters in my string. Instead, I always want to get the second number in my string. The number is always 2 digits.
Example: 001a02.jpg I use the fileparts function to delete the extension of the image (jpg), so I get this string: 001a02
The expected return value is 02
Another example: 001A43a . Return values: 43
Another one: 002A12. Return values: 12
All the filenames are in a matrix 1002x1. Maybe I can use textscan but in the second example, it gives "43a" as a result.
(Just so this question doesn't remain unanswered, here's a possible approach: )
One way to go about this uses splitting with regular expressions (MATLAB's strsplit which you mentioned):
str = '001a02.jpg';
C = strsplit(str,'[a-zA-Z.]','DelimiterType','RegularExpression');
Results in:
C =
'001' '02' ''
In older versions of MATLAB, before strsplit was introduced, similar functionality was achieved using regexp(...,'split').
If you want to learn more about regular expressions (abbreviated as "regex" or "regexp"), there are many online resources (JGI..)
In your case, if you only need to take the 5th and 6th characters from the string you could use:
D = str(5:6);
... and if you want to convert those into numbers you could use:
E = str2double(str(5:6));
If your number is always at a certain position in the string, you can simply index this position.
In the examples you gave, the number is always the 5th and 6th characters in the string.
filename = '002A12';
num = str2num(filename(5:6));
Otherwise, if the formating is more complex, you may want to use a regular expression. There is a similar question matlab - extracting numbers from (odd) string. Modifying the code found there you can do the following
all_num = regexp(filename, '\d+', 'match'); %Find all numbers in the filename
num = str2num(all_num{2}) %Convert second number from str
I want to grab the first char of a var string and the first char of the following caracter
Example:
$var1 = "Jean-Martin"
I want a way to grab the first letter "J" then I want to take the first char following the "-" (dash) which is "M".
Something like this?
$initial1 = $var1[0]
$initial2 = $var1.Split('-')[1][0]
Strings in Powershell use the System.String class from the .Net framework. As such, they are indexable to retrieve individual characters and have many methods available such as the Split method used above.
See the documentation here.
$var1 = "Jean-Martin"
To get the first character:
$var1[0]
To get the first character after the dash:
$characterToSeek = '-'
$var1[$var1.IndexOf($characterToSeek)+1]
Another option using regex:
PS> $var1 -replace '^(.)[^-]+-(.).+$','$1$2'
JM