PowerShell Add-Content
last modified February 15, 2025
In this article, we will cover the Add-Content cmdlet in
PowerShell. This cmdlet appends content to files without overwriting
existing content. It's useful for logging and data collection.
Add-Content basics
The Add-Content cmdlet adds content to a specified file. Unlike
Set-Content, it preserves existing content. It can add text,
arrays, or file contents. The cmdlet creates the file if it doesn't exist.
It supports various encodings and can work with multiple files.
Basic Add-Content usage
The simplest way to use Add-Content is with a file path and
content string. This appends the text to the specified file. If the file
doesn't exist, it will be created. The default encoding is UTF-8.
Add-Content -Path "log.txt" -Value "New log entry"
This command appends "New log entry" to log.txt. If log.txt doesn't exist, it will be created. Each execution adds a new line to the file.
Appending multiple lines
You can append multiple lines by passing an array of strings. Each array element becomes a separate line in the file. This is useful for adding structured data. The -Value parameter accepts both single and multiple values.
$lines = @("First line", "Second line", "Third line")
Add-Content -Path "data.txt" -Value $lines
This command adds three lines to data.txt. Each string in the array becomes a separate line. The file will contain these lines in the specified order.
PS C:\> Get-Content data.txt First line Second line Third line
Appending with different encoding
You can specify the file encoding using the -Encoding parameter. This is important for compatibility with different systems. Common encodings include UTF8, ASCII, and Unicode. The default is UTF8NoBOM in PowerShell 6+.
Add-Content -Path "output.txt" -Value "Text with special chars: äöü" -Encoding UTF8
This command appends text with special characters using UTF-8 encoding. The encoding ensures proper handling of non-ASCII characters. Choose the encoding based on your requirements.
Appending to multiple files
Add-Content can append to multiple files simultaneously. Provide
multiple paths or use wildcards. This is efficient for batch operations.
All specified files receive the same content.
Add-Content -Path "file1.txt", "file2.txt" -Value "Common content"
This command appends "Common content" to both file1.txt and file2.txt. If either file doesn't exist, it will be created. Wildcards like *.log can also be used.
Using pipeline input
Add-Content can accept input from the pipeline. This allows
dynamic content generation. The input can come from other cmdlets or
functions. This is powerful for processing and logging data.
Get-Date | Add-Content -Path "timestamps.log"
This command appends the current date and time to timestamps.log. The
Get-Date output is piped directly to Add-Content.
This pattern is common for logging scenarios.
Appending with confirmation
For safety, you can add confirmation prompts. The -Confirm parameter prompts before writing. This prevents accidental modifications. Useful when working with important files.
Add-Content -Path "important.txt" -Value "Critical data" -Confirm
This command shows a confirmation prompt before appending. You must confirm the action by typing 'Y'. The prompt includes the target file path.
Using -NoNewline parameter
By default, Add-Content adds a newline after each value. The
-NoNewline parameter prevents this. Useful when you need to append without
line breaks. Multiple appends will be on the same line.
Add-Content -Path "output.txt" -Value "Start: " -NoNewline Add-Content -Path "output.txt" -Value "Continued text"
The first command adds "Start: " without a newline. The second appends "Continued text" on the same line. The file will contain "Start: Continued text".
Source
In this article, we have covered the Add-Content cmdlet in PowerShell.
Author
List all PowerShell tutorials.