PowerShell: Write to File

Write to File

Set-Content

Write to file, with value parameter or piped input. If the file doesn't exit, it'll be created.

Set-Content "test.txt" -value "something"

dir | Set-Content "test.txt"

• -NoNewline → do not add a CRLF at end of file.
• -Encoding → default to utf8.

Here's a alternative, using .NET method:

[IO.File]::WriteAllText(file_path, content)

write content string to file at file_path.

Append to file

Add-Content (alias ac)

append content to file.

Output to File

Out-File

write output to file, from a piped input.

dir | Out-File "test.txt" -width 111222333 -NoNewLine

• -width → max number of characters per line, any beyond is DELETED.
• -NoNewline → do not add a CRLF at end of file.
• -Encoding → default to utf8.
• -Append → append to end.
• -NoClobber → warn before overwrite.

To String

Out-String

convert input objects into one single string, or use Stream parameter to return array of strings.
Out-string is useful when you need to manipulate the string before sending to file.

To Pipeline

Write-Output (alias echo , write)

sends objects to the pipeline. If it is the last command, send them to screen.
Use -NoEnumerate to make the output as one single string.
Note, if the out-string command is wrapped in parentheses, the parentheses force enumeration.

To Screen

Write-Host

print to screen. Useful for user prompt.

Auto to Screen

Out-Host

send output to screen. Out-Host is automatically appended to every command that is executed. To suppress it, pipe to out-null. More efficient way is to assign it to $null. e.g. $null = mkdir dirName