package mlgpx

  1. Overview
  2. Docs
Library and CLI for parsing and generating GPS Exchange (GPX) formats

Install 

dune-project
 Dependency

tangled.sh Readme Changelog ISC License Edit opam file Versions (1)

Authors

  1. A
    Anil Madhavapeddy

Maintainers

  1. A
    Anil Madhavapeddy <anil@recoil.org>

Sources

mlgpx-1.0.0.tbz
md5=5342bb7e601273245a9fe263e5a08770
sha512=cd73b16e988b3ed3cc427a6c6c6d6c9c745adb1eb7efaae3c34e8d006e9c03d9f9d2616cd4118564bd9873903969d3e4053b585e79dbd3e3e7d0f541e2faac83

doc/src/mlgpx.unix/gpx_io.ml.html

Source file gpx_io.ml

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(** GPX Unix I/O operations *)


(** Result binding operators *)
let (let*) = Result.bind

(** Read GPX from file *)
let read_file ?(validate=false) filename =
  try
    let ic = open_in filename in
    let input = Xmlm.make_input (`Channel ic) in
    let result = Gpx.parse ~validate input in
    close_in ic;
    result
  with
  | Sys_error msg -> Error (Gpx.Error.io_error msg)
  | exn -> Error (Gpx.Error.io_error (Printexc.to_string exn))

(** Write GPX to file *)
let write_file ?(validate=false) filename gpx =
  try
    let oc = open_out filename in
    let dest = `Channel oc in
    let result = Gpx.write ~validate dest gpx in
    close_out oc;
    result
  with
  | Sys_error msg -> Error (Gpx.Error.io_error msg)
  | exn -> Error (Gpx.Error.io_error (Printexc.to_string exn))

(** Read GPX from stdin *)
let read_stdin ?(validate=false) () =
  let input = Xmlm.make_input (`Channel stdin) in
  Gpx.parse ~validate input

(** Write GPX to stdout *)
let write_stdout ?(validate=false) gpx =
  Gpx.write ~validate (`Channel stdout) gpx

(** Check if file exists and is readable *)
let file_exists filename =
  try
    let _ = Unix.stat filename in
    true
  with
  | Unix.Unix_error _ -> false

(** Get file size *)
let file_size filename =
  try
    let stats = Unix.stat filename in
    Ok stats.st_size
  with
  | Unix.Unix_error (errno, _, _) -> 
    Error (Gpx.Error.io_error (Unix.error_message errno))

(** Create backup of file before overwriting *)
let create_backup filename =
  if file_exists filename then
    let backup_name = filename ^ ".bak" in
    try
      let ic = open_in filename in
      let oc = open_out backup_name in
      let rec copy () =
        match input_char ic with
        | c -> output_char oc c; copy ()
        | exception End_of_file -> ()
      in
      copy ();
      close_in ic;
      close_out oc;
      Ok backup_name
    with
    | Sys_error msg -> Error (Gpx.Error.io_error msg)
    | exn -> Error (Gpx.Error.io_error (Printexc.to_string exn))
  else
    Ok ""

(** Write GPX to file with backup *)
let write_file_with_backup ?(validate=false) filename gpx =
  let* backup_name = create_backup filename in
  match write_file ~validate filename gpx with
  | Ok () -> Ok backup_name
  | Error _ as err ->
    (* Try to restore backup if write failed *)
    if backup_name <> "" && file_exists backup_name then (
      try
        Sys.rename backup_name filename
      with _ -> ()
    );
    err