module Shell_fs:sig..end
Shell filesystem
This module emulates a filesystem by submitting shell commands.
For example, a directory listing is retrieved via the ls
utility instead of opening the directory directly. This also
works when logging in to a remote machine, e.g. via ssh.
The following standard POSIX commands are used:
dd with options if, of, bs, skip, conv=notrunc,
and optionally excl (the latter is a GNU extension)test with options -d, -e, -f, -r, -s, -w, -xls with options -1, -n, -d, -a, -Lrm with options -r and -fmv with option -fln with option -smkdir with options -prmdircp with option -pIn addition to this, the commands may be embedded in one-line shell scripts.
Filenames with leading minus chars are not supported.
Error reporting is less accurate than for a local filesystem.
Example. List a directory on a remote system:
let fs =
Shell_fs.shell_fs
(Shell_fs.ssh_interpreter ~host:"moon" ())
let files =
fs # readdir [] "/this/is/a/directory/on/moon"
type command_context = {
|
sfs_command : |
(* | The command line | *) |
|
sfs_stdin : |
(* | stdin from here | *) |
|
sfs_stdout : |
(* | stdout goes here | *) |
|
sfs_stderr : |
(* | stderr goes here | *) |
|
mutable sfs_status : |
(* | The exit code is put here | *) |
type command_interpreter
The interpreter runs the command, and fills in sfs_status
val local_interpreter : unit -> command_interpreterExecutes commands on the local machine
val cmd_interpreter : (command_context -> Shell_sys.command list) ->
command_interpreterCreates a command interpreter from a function that creates the real command (as pipeline) to execute
val ssh_interpreter : ?options:string list ->
?user:string -> host:string -> unit -> command_interpreterExecutes commands via ssh on the machine host as user (defaults
to current user). options are further command-line options.
By default, only -o BatchMode yes is passed.
class type shell_stream_fs =object..end
class shell_fs :?encoding:Netconversion.encoding -> ?root:string -> ?dd_has_excl:bool -> ?tmp_directory:string -> ?tmp_prefix:string -> command_interpreter ->shell_stream_fs
val shell_fs : ?encoding:Netconversion.encoding ->
?root:string ->
?dd_has_excl:bool ->
?tmp_directory:string ->
?tmp_prefix:string ->
command_interpreter -> shell_stream_fsThe shell filesystem.
encoding: the assumed character encoding of the filenames.
None by default.root: the root of the file tree that is accessed. This can
be an absolute path, or a relative path. dd_has_excl: whether the dd command support "conv=excl".
Default is false; this is a GNU extension.tmp_directory and tmp_prefix are only meaningful for
the write_file method which creates a temporary file.
See Netchannels.make_temporary_file for more information.shell_stream_fsval execute : command_interpreter -> command_context -> unitStarts this command. It is not waited until the command is finished.
One can either call wait for this, or one of the adapter
functions below.
One can only start one command at a time.
val wait : command_interpreter -> unitWaits until the running command is finished
val output_stream_adapter : ci:command_interpreter ->
close_in:(unit -> unit) ->
skip:int64 -> Shell.consumer * Netchannels.in_obj_channelArranges that the output of a shell command is made available as
an in_obj_channel:
let (c, ch) = output_stream_adapter ~ci ~close_in ~skip
The consumer p can be used in a command_context for either
sfs_stdout or sfs_stderr. The channel ch is an input
channel, and when reading from it will return the bytes of
stdout or stderr.
close_in is called as post-hook when the close_in method of
ch is called.
skip bytes of stdout/stderr are skipped at the beginning of the
stream.
val input_stream_adapter : ci:command_interpreter ->
close_out:(unit -> unit) -> Shell.producer * Netchannels.out_obj_channelArranges that the input of a shell command is made available as
an out_obj_channel:
let (p, ch) = input_stream_adapter ~ci ~close_in
The producer p can be used in a command_context for
sfs_stdin. The channel ch is an output
channel, and bytes written to it will appear in stdin of the
executed command.
close_out is called as post-hook when the close_out method of
ch is called.