System.IO.File (static class)

System.IO.File only has static methods and allows for generic file related operations in a file system.

In contrast, System.IO.FileInfo represents a specific file.

Methods

`AppendAllLines()`
`AppendAllLinesAsync()`
`AppendAllText()`
`AppendAllTextAsync()`
`AppendText()`
`Copy()`
`Create()`
`CreateSymbolicLink()`
`CreateText()`
`Decrypt()`
`Delete()`
`Encrypt()`
`Exists()`	Checks if a file exists.
`GetAttributes()`
`GetCreationTime()`
`GetCreationTimeUtc()`
`GetLastAccessTime()`
`GetLastAccessTimeUtc()`
`GetLastWriteTime()`
`GetLastWriteTimeUtc()`
`Move()`
`Open()`
`OpenHandle()`
`OpenRead()`
`OpenText()`
`OpenWrite()`
`ReadAllBytes()`
`ReadAllBytesAsync()`
`ReadAllLines()`
`ReadAllLinesAsync()`
`ReadAllText()`	Slurps the content of an entire file.
`ReadAllTextAsync()`
`ReadLines()`
`Replace()`
`ResolveLinkTarget()`
`SetAttributes()`
`SetCreationTime()`
`SetCreationTimeUtc()`
`SetLastAccessTime()`
`SetLastAccessTimeUtc()`
`SetLastWriteTime()`
`SetLastWriteTimeUtc()`
`WriteAllBytes()`	Creates a new or overwrites an existing file, writes the specified byte array to the file, and then closes the file.
`WriteAllBytesAsync()`
`WriteAllLines()`
`WriteAllLinesAsync()`
`WriteAllText()`
`WriteAllTextAsync()`

Why is there no WriteAllBytes() method?

Exists

The method Exists checks if a file exists.

Compare with the test-path cmdLet.

ReadAllText

ReadAllText slurps the content of an entire file.

Concatenating multiple files

The following example concatentas multiple files in PowerShell:

PS: C:\> $a = [IO.File]::ReadAllText("$pwd\a.txt")
PS: C:\> $b = [IO.File]::ReadAllText("$pwd\b.txt")
PS: C:\> $c = [IO.File]::ReadAllText("$pwd\c.txt")
PS: C:\> [IO.File]::WriteAllText("$pwd\concatenated" , $a)
PS: C:\> [IO.File]::AppendAllText("$pwd\concatenated", $b)
PS: C:\> [IO.File]::AppendAllText("$pwd\concatenated", $c)

Of course, the canonical way would be something like the following, but is tends to mess things because it sometimes writes BOMs:

get-content a.txt,b.txt,c.txt | set-content concatenated.txt