Handling Special Characters within CSV with PowerShell using Encoding
When working with CSV files in PowerShell with special characters you might encounter an issue where special characters (e.g., em dashes —) are incorrectly represented as a question mark inside a diamond �. This common issue arises due to PowerShell’s default encoding not matching the encoding used in the CSV file.
Problem Statement
The root of this problem lies in the encoding mismatch. Encoding is a method of converting characters into a format that can be easily stored or transmitted. Different applications and systems use various encoding standards, and when these standards don’t match, special characters can appear garbled.
For example, consider a CSV file containing special characters. When you try to import this file into PowerShell using the Import-Csv cmdlet without specifying an encoding, PowerShell uses its default encoding. If the default encoding doesn’t align with the file’s encoding, special characters will not display correctly.
import-csv -Path $csvPath
Special characters e.g. — from excel turning into � powershell by default if no encoding parameters are used
Solution: Use Encoding parameter
To resolve this issue, you can specify the encoding of the CSV file using the -Encoding parameter in the Import-Csv cmdlet. For many Western languages, the ansi encoding option can correctly handle special characters.
Encoding Options
PowerShell supports several encoding options, each suitable for different scenarios:
Note: The below description of the different encodings has been generated by Github Copilot.
Default: Uses the default encoding for the PowerShell session. UTF8: A popular encoding that supports all Unicode characters. Use UTF8 for maximum compatibility across different platforms and applications. UTF8BOM (UTF-8 with Byte Order Mark): This variant of UTF-8 includes a Byte Order Mark (BOM) at the beginning of the text file. The BOM is a sequence of bytes (EF BB BF) that indicates the file is encoded in UTF-8. It can be helpful for applications to recognize the file’s encoding automatically, but some tools might not handle the BOM correctly and could display or process these bytes as visible characters. UTF8NoBOM (UTF-8 without Byte Order Mark): This is UTF-8 encoding without the BOM. It’s preferred when compatibility with systems or applications that do not recognize the BOM is necessary. Using UTF8NoBOM ensures that no extra bytes are added at the beginning of the file, avoiding potential issues with software that does not expect or handle the BOM correctly. UTF7, UTF32, ASCII, Unicode: Other Unicode and ASCII encodings, each with specific use cases. BigEndianUnicode: Similar to Unicode but stores characters in big-endian byte order. OEM: Uses the default encoding for the system’s current OEM code page. ANSI: This is often a good choice for files from Windows-based applications.
Solution for dash —
The solution importing csv file with dash — was to use encoding ansi.
import-csv -Path $csvPath -Encoding ansi
