An ocaml parser of '/proc/self/smaps'
(See /proc/[pid]/smaps section in man proc for details).

Specification

proc-smaps parses mappings. A mapping is such as below.

00400000-0048a000 r-xp 00000000 fd:03 960637       /bin/bash
Size:                552 kB
KernelPageSize:        4 kB
  :
ProtectionKey:         0
VmFlags: rd ex mr mw me dw

A mapping corresponds to Smaps.t.
Smaps.get_smaps <pid> returns Smaps.t list Result.t Lwt.t.
When mapping : Smaps.t is derived from this mapping,
mapping.pathname is "/bin/bash",
mapping.perms is 0b10101 (each bits represent 'rwxsp') and Smaps.get_size_exn mapping "Size" is 552 : uint64.

Device and fields that does not include byte size such as ProtectionKey, VmFlags are not supported now.

Example

# let smaps = Smaps.get_self_smaps ()
    |> Lwt_main.run
    |> Result.get_ok;;
val smaps : Smaps.t list = ...
# (Stdint.Uint64.to_string @@ Smaps.sum_rss smaps) ^ " KB"
- : string = "19640 KB"
# List.hd smaps;;
- : Smaps.t =
{Smaps.address = (<abstr>, <abstr>); perms = 21; offset = <abstr>; inode = 0;
 pathname = "[vdso]"; size_fields = <abstr>}
# List.map (fun x -> Smaps.get_size_exn x Smaps.pss |> Stdint.Uint64.to_int) smaps;;
- : int list = ...