Module Topkg.OS.File

module File: sig .. end
File operations.

Famous file paths

val null : Topkg.fpath
null represents a file on the OS that discards all writes and returns end of file on reads.
val dash : Topkg.fpath
dash is "-". This value is is used by and Topkg.OS.File.write to respectively denote stdin and stdout.

Existence and deletion

val exists : Topkg.fpath -> bool Topkg.result
exists file is true if file is a regular in the file system and false otherwise. Symbolic links are followed.
val must_exist : Topkg.fpath -> Topkg.fpath Topkg.result
must_exist file is file if file is a regular file in the file system and an error otherwise. Symbolic links are followed.
val delete : ?must_exist:bool -> Topkg.fpath -> unit Topkg.result
delete ~must_exist file deletes file file. If must_exist is true (defaults to false) an error is returned if file doesn't exist.

Folding over file hierarchies

val fold : ?skip:(Topkg.fpath -> bool) ->
(Topkg.fpath -> 'a -> 'a) -> 'a -> Topkg.fpath list -> 'a Topkg.result
fold_files skip f acc paths folds f over the files found in the file hierarchies starting at paths. Files and directories p for which skip p is true are skipped. skip defaults to (fun _ -> false).

Reading and writing

val read : Topkg.fpath -> string Topkg.result
read file is file's contents. If file is Topkg.OS.File.dash reads from Pervasives.stdin and the channel is not closed when the function returns.
val write : Topkg.fpath -> string -> unit Topkg.result
write file content writes content to file. If file is Topkg.OS.File.dash writes to Pervasives.stdout and flushes but doesn't close the channel when the function returns.
val write_subst : Topkg.fpath -> (string * string) list -> string -> unit Topkg.result
write_subst file vars content is like Topkg.OS.File.write except any occurence of a string of the form "%%ID%%" in content is replaced by the value of List.assoc "ID" vars, if any.

Temporary files

val tmp : unit -> Topkg.fpath Topkg.result
tmp () creates a temporary file and returns its name. The file is destroyed at the end of program execution.