let squashStrArray (str_arg : string[]) =
let array_len = str_arg.Length
let rec inner_squash (inner_str_arg : string []) (build_up_list : string) idx =
if idx = array_len then
build_up_list
else
let build_up_list = inner_str_arg.[idx] + " " + build_up_list
inner_squash inner_str_arg build_up_list (idx + 1)
inner_squash str_arg "" 0
Tag: F#
I discovered a nice utility that accompanies Visual Studio; at least it is in Visual Studio 2015. It is called ilmerge. It specific purposes is to fold an executable along with any dependent DLLs into a new executable that requires no external dependencies. You might need this for those time when you want a single executable on, say, a remote system.
Here is a command that binds two .Net libraries, one a distributed Microsoft API and the other is part of my program.
ilmerge /log:ilmerge.log ` /lib:C:\Windows\Microsoft.NET\Framework\v4.0.30319 ` /target:winexe /targetplatform:v4 ` /out:FreeBytesC.exe ` /ndebug FreeBytes.exe ` FreeBytes.exe FSharp.Core.dll VolLib.dll
The library and application have been updated to be a little more flexible and take a parameter, so that the minimum free space does not have to be hard-coded into the program.
Here is VolLib, an F# library:
namespace Toa.volLib
open System
open System.Threading
open System.Collections.Generic
open System.Text
open System.IO
open Microsoft.Win32
type DiskFreeLevels =
| DRIVE_OFF_LINE = -1L
| GB1 = 1000000000L
| GB5 = 5000000000L
| GB10 = 10000000000L
| GB20 = 20000000000L
[<AutoOpen>]
module volLib =
let libInit = ref false
let drive_list () =
DriveInfo.GetDrives()
// Takes a string representation of a drive, and pulls out its free space.
let free_space drive =
let di = DriveInfo(drive)
if di.IsReady then
int64(di.AvailableFreeSpace)
else
int64(-1)
// Just convert bytes to gigabytes.
let cvt_bytes_to_gb (in_bytes:int64) =
int64(truncate((float(int64(in_bytes)) / float(1024L)
/ float(1024L)) / float(1024L)))
let DRIVE_OFF_LINE = int64(-1)
let GB1 = cvt_bytes_to_gb(int64(DiskFreeLevels.GB1))
let GB5 = cvt_bytes_to_gb(int64(DiskFreeLevels.GB5))
let GB10 = cvt_bytes_to_gb(int64(DiskFreeLevels.GB10))
let GB20 = cvt_bytes_to_gb(int64(DiskFreeLevels.GB20))
// This is a pipeline function that takes a drive letter (string) and
// returns the free GB from a DriveInfo structure.
let cvt_drive_to_free_gb drive =
let fs = free_space drive
if fs > DRIVE_OFF_LINE then
free_space drive |> cvt_bytes_to_gb
else
int64(-1)
let cvt_gb_arg_to_int (arg:string) =
let numeric_arg = arg.Substring(2, arg.Length - 4)
int64(numeric_arg)
and the main application
(*
A simple checker of Windows disks.
Charles M. Norton 11/01/2016
Will be greatly improved over time.
Modifications
Charles M. Norton 11/1/2016
Initial version.
*)
open System
open System.Text
open System.Net.Mail
open System.IO
open System.Threading
open Microsoft.VisualBasic.FileIO
open System.Collections.Generic
open Toa.volLib // local library
let send_email msg =
use msg =
new MailMessage ("dbadmin@somewhere.sometown.us",
@"dbadmin@town.arlington.ma.us", @"Disk Space Report\n",
msg )
use client = new SmtpClient(@"webmail.somewhere.sometown.us")
client.DeliveryMethod <- SmtpDeliveryMethod.Network
client.Credentials <-
new System.Net.NetworkCredential("dbadmin", "xxxxxx")
client.Send msg
let match_head = "--"
let match_tail = "GB"
let contains_match_constants (arg:string) =
if arg.StartsWith match_head && arg.EndsWith match_tail then
true
else
false
let parse_min_gb_arg arg =
if contains_match_constants arg then
cvt_gb_arg_to_int arg
else
volLib.GB1
let no_disk = int64(-1)
[<EntryPoint>]
let main argv =
let min_gb =
if argv.Length > 0 then
parse_min_gb_arg argv.[0]
else
volLib.GB1
let local_drive_list = drive_list ()
let check_file = "free_bytes_check.txt"
let system_name = System.Environment.MachineName
let system_drive = Path.GetPathRoot(Environment.SystemDirectory)
let display_info = new List<string>()
display_info.Add("System name " + system_name + "\n")
let drive_list_len = local_drive_list.Length
for idx = 0 to (drive_list_len - 1) do
let drive_name = (Seq.item idx local_drive_list).Name
let free_gb = cvt_drive_to_free_gb drive_name
let display_row = "Volume: " + drive_name + "\n" + "Free Space: " +
free_gb.ToString() + "GB\n"
display_info.Add(display_row)
let curr_time = DateTime.Now
let gb_c = cvt_drive_to_free_gb system_drive
let gb_d = cvt_drive_to_free_gb "D:\\"
let gbs = display_info |> String.concat("\n")
if not (File.Exists check_file) then
use swH = new StreamWriter(check_file, true)
swH.WriteLine(curr_time.ToString())
send_email gbs
else
let fAccessDate = File.GetLastAccessTime(check_file)
let update_stamp = curr_time.Subtract(fAccessDate).Duration() <
TimeSpan.FromDays(7.0)
if not(update_stamp) then
File.WriteAllText(check_file.ToString(), String.Empty)
use swH = new StreamWriter(check_file, true)
swH.WriteLine(curr_time.ToString())
send_email gbs
if gb_c < min_gb || ((gb_d > no_disk) && gb_d < volLib.GB20) then
printfn "Disk free space is below thresholds; send out warning email."
send_email gbs
else
printfn "Disk free space is at or above thresholds. "
printfn "All is well, at least for now."</pre>
<pre> printfn "Sleeping 5 seconds to let you read."
Thread.Sleep 5000 |> ignore
0 // return an integer exit code
So, here is a small, F# program to report on disk usage. This is from a real example on our Munis server.
(* A simple checker of Windows disks. Charles M. Norton 11/01/2016 Will be greatly improved over time. Modifications Charles M. Norton 11/1/2016 Initial version. *) open System open System.Text open System.Net.Mail open System.IO open System.Threading open Toa.volLib // local library let SendEmail msg = use msg = new MailMessage ( "dbadmin@town.arlington.ma.us", @"itadmin@town.arlington.ma.us", @"Munis Server Disk Space Report\n", msg ) use client = new SmtpClient(@"webmail.town.arlington.ma.us") client.DeliveryMethod client.Credentials client.Send msg let main argv = let localDriveList = driveList () let dn = (Seq.head(localDriveList)).Name let drive_c = (Seq.head(localDriveList)).Name let data_drive = (Seq.nth(1) localDriveList).Name let fs_c = freeSpace drive_c let fs_d = freeSpace data_drive let gb_c = cvtBytesToGB fs_c let gb_d = cvtBytesToGB fs_d let system_name = System.Environment.MachineName let strings = ["System name: "; system_name; "Volume "; drive_c; gb_c.ToString(); "GB\n"; "Volume"; data_drive; gb_d.ToString(); "GB\n"] let gbs = String.concat " " strings printfn "System name: %A: Drive C %f -- Data Drive %f" system_name gb_c gb_d if gb_c < volLib.GB5 || gb_d < volLib.GB5 then printfn "Disk free space is below thresholds; send out warning email." SendEmail gbs else printfn "Disk free space is at or above thresholds. All is well, at least for now." printfn "Sleeping 5 seconds to let you read." Thread.Sleep 5000 |> ignore 0 // return an integer exit code
I got a very nice answer on SO to why a function was not executing.
open System
open System.Collections.Generic
open System.Text
open System.IO
#nowarn "40"
let rec readlines () =
seq {
let line = Console.ReadLine()
if not (line.Equals("")) then
yield line
yield! readlines ()
}
[<EntryPoint>]
let main argv =
let inSeq = readlines ()
inSeq
|> Seq.length
|> printfn "%d lines read"
// This will keep it alive enough to read your output
Console.ReadKey() |> ignore
0
