Modern Fs ReplaceFile

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ReplaceFile

Replaces one file with another in a single step, so the target is never missing.

Syntax

ReplaceFile( target, replacement )

Examples

#import "std/fs"
using fs

'' Everything below happens inside a temp directory of its own, and is
'' removed at the end
dim td as FsResultUStr = CreateTempDir( "fbdoc" )
dim as ustring dir_ = td.Value( )

dim as ustring target = PathJoin( dir_, "live.txt" )
dim as ustring newer = PathJoin( dir_, "staged.txt" )
WriteAllText( target, "old" )
WriteAllText( newer, "new" )

'' Replaces the target with the replacement AS ONE OPERATION, so a
'' reader never sees the target missing -- which a remove-then-rename
'' pair cannot promise
print ReplaceFile( target, newer ).IsOk( )       '' true
print ReadAllText( target ).Value( )             '' new
print Exists( newer )                            '' false

'' Both paths must be on the same volume

RemoveDirAll( dir_ )

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Library: Filesystem Library
Category: Filesystem
Documented under: File Operations