PowerShell is a command line shell and scripting language from Microsoft. In this guide, we’ll show you how to use PowerShell replace to replace text in your files or scripts. The syntax for the replacement string will be in place of the first letter of each word that it replaces.,
PowerShell replace is a command-line tool that allows users to search and replace text in files. There are many different ways to use the tool, but this article will only cover some of them. Read more in detail here: powershell replace text in file.
PowerShell, like many other languages, can operate with strings and text. PowerShell may be used to replace characters, strings, or even text inside files, which is a handy function.
You’ll learn how to utilize the PowerShell replace() function and the PowerShell replace operator in this article. The course will go through the fundamentals as well as some “fun” regular expressions.
Before You Begin
You won’t need much to follow along with this tutorial’s examples; all you’ll need is PowerShell. The examples in this lesson will use PowerShell v7.0.2, however they should all work with Windows PowerShell.
The Basics of Using PowerShell to Replace Strings
Replacing characters in strings is one of the most basic uses of PowerShell. Let’s begin with a few examples.
PowerShell Strings: Concatenate, Expand, Format, and Everything
Let’s imagine you have a PowerShell string with the value hello, world.
To make the $string variable have a value of hi, world, you’d want to replace the string hello within that string with the string hi. To do so, PowerShell must first determine the location of the “find” text. It then replaces the text with a user-defined value after it has been discovered.
The Replace() method is used to replace text in a document.
The replace() function, as seen below, is one of the simplest methods to replace text in PowerShell. The replace() function takes two arguments: the string to search for and the string to replace it with.
As you can see in the screenshot below, PowerShell is looking for the word hello and replacing it with the string hi. After that, the procedure delivers the final result, which is “hello, world.”
PS> $string.replace(‘hello’,’hi’) hi, world
To replace a literal string with another, use the replace() function on any string. The replace() function returns null if the string to be substituted isn’t found.
To replace text in a string, you don’t need to assign a string to a variable. Instead, use the replace() function on the string directly, as in ‘hello world’.replace(‘hello’,’hi’). For the sake of simplicity, the tutorial makes use of a variable.
Characters to be Removed
Instead of replacing letters in a string with something else, you may wish to delete them from another string. You may achieve the same thing by using an empty string.
PS> $string.replace(‘hello’,”) , world
Replacing a Large Number of Instances
You now know how to substitute a string inside another string using code. What if you wanted to replace many strings? It’s no issue.
Because the replace() function returns a string, you may put another replace() method call to the end to replace another instance. PowerShell then uses the replace() technique on the original’s output.
PS> $string.replace(‘hello’,”).replace(‘world’,’earth’) , earth
You may use the replace() function as many times as you like, but if you have a lot of strings to replace, you should consider using the replace operator.
Using the Replace Operator in PowerShell
Although the replace() string function is the easiest approach to replace text, the PowerShell replace operator may also be used. In the same way that you submit a string to locate and replace with the method, you may use the replace operator. However, it offers one significant advantage: the ability to locate matched strings using regular expressions (regex) (more later).
Getting Started with PowerShell and Regex is a good place to start.
Using the replace operator, you may replace hello with hi in the same way as in the previous example, as seen below. PowerShell does the same thing.
PS> $string -replace ‘hello’,’hi’ hi, world
Characters to be Removed
The replace operator, like the replace() function, may be used to delete characters from a string. However, unlike the replace() function, you may fully ignore the string as an input to replace with and get the same result.
PS> $string -replace ‘hello’,” , world PS> $string -replace ‘hello’ , world
Replacing a Large Number of Instances
You may use the replace operator in a chain, much as the replace() function. The replace operator, as demonstrated below, returns a string. Regex will make your code clearer, as you’ll see in the following section.
PS> $string -replace ‘hello’,’hi’ -replace ‘world’,’earth’ hi, earth
Regex Replace in PowerShell
As previously stated, the replace() technique in PowerShell works, but it has limitations. You’re limited to utilize just literal strings. You can’t use regex or wildcards. The replace operator should be used if you’re doing any intermediate or advanced replacement.
Let’s imagine you have a script with a variable-created string. Hello, world or hey, world should be the string. Maybe you’ve had a horrible day as a sysadmin and wish to modify the string to farewell, world, regardless of the value.
Hello, world and hello, world must both be changed to farewell, world. You’ll need to employ a regular expression to do this. With regex, you can match almost any precise pattern in text.
As you can see in the example below, you may use the phrase hello|hi to match both needed strings using the regex “or” (|) character.
PS> ‘hello, world’ -replace ‘hello|hi’,’goodbye’ goodbye, world PS> ‘hi, world’ -replace ‘hello|hi’,’goodbye’ goodbye, world
You can use PowerShell to replace wildcard strings that match any pattern after you’ve learned how to utilize regex to discover strings.
Regex Characters Getting Away
The string to search in in the regex example above did not include any regex special characters. Certain characters in the regular expression language, such as most letters and numerals, are not taken literally.
You could, for example, need to replace text in a string. There are a handful of regex special characters in the text, such as a bracket and a question mark. Then, as seen below, attempt to substitute the string [hello] with farewell.
PS> ‘[hello], world’ -replace ‘[hello]’,’goodbye’ [goodbyegoodbyegoodbyegoodbyegoodbye], wgoodbyergoodbyed
Clearly, it was not your intention. When you utilize regex special characters inside of a string to locate anything, this occurs ([hello]).
You have two alternatives for avoiding this issue. You may either prefix each letter with a backslash or use the Escape() function to escape these special characters.
The impact of escaping each special character with a backslash is seen below.
PS> ‘[hello], world’ -replace ‘[hello]’,’goodbye’ goodbye, world
You may also utilize the Escape() function of the regex type to delete all special characters automatically, which is preferred.
PS> ‘[hello], world’ -replace ([regex]::Escape(‘[hello]’)),’goodbye’ goodbye, world
If at all feasible, utilize the Escape() function to escape all special characters so you don’t have to memorize them.
Using Capture/Match Groups
This lesson has used a literal string to substitute another string in all of the preceding examples. You’ve been utilizing the phrases “hello” and “goodbye.” But what if you want to change one or more characters discovered in the string using PowerShell? Groups must be matched or captured.
Capture groups and backreferences are a notion in Regex. Capture groups enable you to capture strings that you may later use in other places. By combining match groups with the replace operator in PowerShell, it is possible to take use of these functionalities.
For example, suppose you have a string that can hold a variety of values.
‘hey world, you gorgeous beast,’ ‘hello world, now get out of here,’ ‘hello earth, you are wonderful today,’
You’d want to switch the first and second parts of the string so that they appear like this:
‘hey world, you gorgeous beast’ ‘now go away,hello world’ ‘you are wonderful today,hello earth’
PowerShell must locate all of the text to the right and left of the comma in order to complete this operation. It must then replace one with the other after it has determined what that text is. Backreferences are required for this.
A backreference is a regex variable (rather than a PowerShell variable) that reflects the text that the regex found. In PowerShell, backreferences are denoted by a dollar sign followed by a number that indicates the sequence in which they were matched.
Here’s an example of what I’m talking about.
## This string could also be: ## ‘hi, world, now go away’ ## ‘hello, earth, you are lovely today’ PS> $string = ‘hello, world, you sexy beast’ PS> $string -replace ‘(.*), (.*)’,’$2,$1′ you sexy beast,hello world
You can see regex capture groups encapsulating each match (hello world) and (you gorgeous beast) with parenthesis in the example above. Then, for the replacement, the hello word was matched first from left to right, resulting in a $1 backreference label for it and a $2 backreference label for you gorgeous beast.
You may utilize these references in the replacement text in any manner once PowerShell knows the value for each match. $2,$1 swaps their places in this case.
Making Use of Named Match Groups
You may also use labels or names to reference match values if you don’t want to use numerical placeholders like $1, $2. You may utilize names instead of counting from left to right to figure out what each reference means.
To use names as references, you need to first define labels for each match in the match string. To do that, you must define the capture group like (?<label><regex>) where label is the name and <regex> is the regular expression you are using.
After you’ve specified the names, you may use a dollar sign and curly brackets to refer to them in the replace string, for example, $label.
This approach is shown in the video below.
PS> $string = ‘hello, world, you sexy beast’ PS> $string -replace ‘(?<First_Part>.*), (?<Second_Part>.*)’,’${Second_Part},${First_Part}’ you sexy beast,hello, world
Conclusion
PowerShell enables you to substitute characters, text, and strings in a variety of ways, as you’ve seen. You may use the replace() method to do basic replacements, but if you need to match and replace anything more complex, you should always use the replace operator.
The “powershell replace ((regex))” is a command that allows users to use regular expressions to find and replace text. This article will provide examples of how the command can be used.
Frequently Asked Questions
How do you replace text in PowerShell?
A: It is not possible to replace text in PowerShell commands.
How do you replace a word in PowerShell?
A: To replace a word in PowerShell, you would use the following command. This will delete orange and create red.
How do I replace a value in PowerShell?
A: For example, you want to replace the value Fred with Joe. If you wanted to do this in PowerShell, then your command would look something like this.
Related Tags
- powershell replace text in file with variable
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