VS 2010 Parsing concatenated string

Parsing concatenated string

Hi,

I am writing a tool that logs stats for a first person shooter game. The game writes its information (including who killed who with which weapon) to a log file, which I read every so many seconds and parse so that I can write that information to a database.

I am now having trouble parsing the weapon out of that string of information.

Some additional information is required: a weapon in this game can contain attachments (such as a scope, a grenade launcher, etc). Weapons can have either 1 or 2 attachments. Some weapons however cannot have any attachments at all.

Each log file entry that describes a kill contains a code that describes the weapon that was used. This code is a concatenation of either 3 or 4 parts:

Code:

<weapon>_<attachment>_mp <weapon>_<attachment1>_<attachment2>_mp

where <weapon> is a code that describes a weapon and <attachment> is another code describing the attachment.

This should be easy to parse by just splitting along the underscore characters, but there's a few catches:

1. Some attachments are able to kill players as well. Specifically: grenade launchers, flame throwers and underbarrel shotguns. In this case, the attachment is listed before the weapon:

Code:

<attachment>_<weapon>_mp

Note also that in this case there is always only 1 attachment.

2. The biggest catch: some weapon names have an underscore in them (some even have 3 underscores)! So simply splitting along the underscore won't work in all cases; if the weapon name contains an underscore I'm splitting the name of the weapon...

This makes the list of possible combinations a lot longer. The ones I can think of (I think these are all):

Code:

Weapon names without underscores: 1. <weapon>_mp - No attachments 2. <weapon>_<attachment>_mp - One attachment 3. <attachment>_<weapon>_mp - Attachment kill 4. <weapon>_<attachment>_<attachment>_mp - Two attachments Weapon names with underscores: 5. <weaponpart1>_<weaponpart2>_mp - No attachments 6. <weaponpart1>_<weaponpart2>_<weaponpart3>_mp - No attachments 7. <weaponpart1>_<weaponpart2>_<weaponpart3>_<weaponpart4>_mp - No attachments

Luckily, all weapons with an underscore in their name cannot have any attachments. Probably a coincidence, but that makes the list a lot shorter (otherwise the first 4 options would be repeated for option 5, 6 and 7, making a total of 19 options if I counted correctly).

My question now I guess: can anyone see an easy way to parse this weapon code so that I can extract the weapon name and the attachments used separately? I started out with splitting along the underscore and checking the length of the resulting array. If the length is 2 then it's always option 1. If the length is 3 then there's already 3 options. This adds up really fast, my code was already way too long at this point and impossible to understand :lol: This approach requires a lot of "trial and error", where I parse out the first part and basically do;
1. Check if it represents a weapon
2. If not, check if it's an attachment
3. If not, check if it's part of a weapon

As you can imagine this gets really ugly. There must be a better way to parse this stuff?

If anyone can see an easy way please let me know!

Finally if you need it here's the list of weapons and attachments:

Weapons (code, full name, bitmask of possible attachments):

Code:

ak47 AK47 37627 ak74u AK74u 49595 asp ASP 262144 aug AUG 37627 knife_ballistic Ballistic Knife 0 china_lake China Lake 0 m1911 M1911 295968 commando Commando 37627 crossbow_explosive Crossbow 0 cz75 CZ75 820256 dragunov Dragunov 164385 enfield Enfield 37627 famas Famas 37627 fnfal FN FAL 37627 g11 G11 133120 galil Galil 37627 hk21 HK21 563 hs10 HS10 262144 ithaca Stakeout 256 kiparis Kiparis 311603 knife Knife 0 l96a1 L96A1 164385 m14 M14 37875 m16 M16 37627 m60 M60 819 m72_law M72 LAW 0 mac11 MAC11 311602 makarov Makarov 295968 mp5k MP5K 49203 mpl MPL 49435 pm63 PM63 278816 psg1 PSG1 164385 python Python 335873 rottweil72 Olympia 0 rpg RPG 0 rpk RPK 571 skorpion Skorpion 311584 spas SPAS-12 32768 spectre Spectre 49459 stoner63 Stoner63 563 strela Strela-3 0 uzi Uzi 49459 wa2000 WA2000 164385 concussion_grenade Concussion Grenade 0 flash_grenade Flash Grenade 0 frag_grenade Frag Grenade 0 sticky_grenade Semtex 0 tabun_gas Nova Gas 0 willy_pete Willy Pete 0 ft Flamethrower 0 gl Grenade Launcher 0 mk Masterkey Shotgun 0 airstrike Rolling Thunder 0 auto_gun_turret Sentry Gun 0 cobra_20mm_comlink Attack Helicopter 0 dog_bite Attack Dogs 0 hind_minigun_pilot_firstperson Gunship [Minigun] 0 huey_minigun_gunner Chopper Gunner 0 m220_tow Valkyrie Rockets 0 mortar Mortar Team 0 napalm Napalm Strike 0 rcbomb RC-XD 0 claymore Claymore 0 satchel_charge C4 0 hatchet Tomahawk 0 explosive_bolt Explosive Bolt 0 explodable_barrel Explodable Barrel 0 hind_rockets_firstperson Gunship [Rockets] 0 minigun_mp Death Machine 0 m202_flash Grim Reaper 0

Attachments (code, full name, bitmask):

Code:

acog ACOG Sight 1 reflex Reflex Sight 2 drum Drum Mag 4 dualclip Dual Mag 8 elbit Red Dot Sight 16 extclip Extended Mag 32 ft Flamethrower 64 gl Grenade Launcher 128 grip Grip 256 ir Infrared Scope 512 upgradesight Upgraded Iron Sights 1024 lps Low Power Scope 2048 mk Masterkey 4096 speed Speed Reloader 8192 rf Rapid Fire 16384 silencer Suppressor 32768 snub Snub Nose 65536 vzoom Variable Zoom 131072 dw Dual Wield 262144 auto Full Auto Upgrade 524288

The code is the name of the weapon as it gets written to the log file (so this is the name I am parsing out, the full name is irrelevant). As you can also see, there's some weapons with underscores in the name, but all of them have an attachments bitmask of 0 meaning they cannot have any attachments.

Re: Parsing concatenated string

Hi Nick,

I don't think there is any way you can write a function that will always return the weapon name from what you have described.

Since the weapons and attachments are all wrapped using <>'s the only way to tell one apart from the other would be using some form of lookup.

I was thinking a regex pattern would be the most practicle way to get the information you need. You could also write an IndexOf function to achieve the same results but the results as far as I can see are always going to contain an array of strings. And that array is always going to be either:

WeaponName, Attachment etc.
Or
Attachment, WeaponName

With those results you are never going to be able to tell the Weapon apart from the attachment, if the resulting array contains 2 strings, without a precompiled list to compare each result to.

Can you create a list of strings containing all of the weapon values and/or the same for the attachments. Then when you have narrowed the input from your log file you can loop through your list(s) to see what weapon/attachment(s) was used.

Re: Parsing concatenated string

Sorry, the names are not wrapped in braces <>, that was just to indicate a 'place holder'.

A few data examples:

Code:

ak47_mp (normal ak47) ak47_silencer_mp (ak47 with silencer) ft_ak47_mp (flamethrower under ak47, killed by fire) ak47_ft_mp (ak47 with flamethrower, killed by bullets) hind_minigun_pilot_firstperson_mp (helicopter bullets)

And I do have a list of all possible weapon/attachment names, that's the two lists at the end of my post.

I can of course just try if there's a match in those lists, but that would get quite ugly, so I was hoping someone could come up with a better way.

Re: Parsing concatenated string

You can try working this from a different direction. I am assuming that _mp is the bitmap value.

Start by first checking the last to characters in your string. If the value is _0, trim the last two characters and you are left with the weapon name. (Conditions 5 6 or 7)

If not you can split the string by the _.
Result 2 = Condition 1
Result 4 = condition 4

Result 3
The final 2 conditions can be parsed out by grabbing the mp value and converting it to binary.
If the result has only 1 "1" in it. it is an attachment Condition 3
If not you are left with condition 2.

If I am wrong about the MP value then of course this post will be no help at all.

Re: Parsing concatenated string

No, mp is just mp, always. It just means 'multiplayer'. It's kind of redundant, I know, but hey I did not decide how the log files are written ;)

Re: Parsing concatenated string

Hi Nick,

Have you made any progress? If not I have managed to make a function that can retrieve the weapons/attachments from the log string. I used a couple of HashTables to accomplish it and used the HashCodes of the weapon names as the Keys. All of the HashCodes are unique and I assume they would be on every other OS as well.

I don't know if it's by any means the best approach or how quickly it will perform within a loop but maybe it will help you find a better method if it doesn't perform all that well:

VB.NET Code:

Imports System.IO
 
Public Class Form1
    Dim HTWeapons As New Hashtable
    Dim HTAttachments As New Hashtable
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
 
        'Weapons HashTable
        Dim Weapons() As String = File.ReadAllLines("Path\Weapons.txt")
        For Each w As String In Weapons
            HTWeapons.Add(w.GetHashCode, w)
        Next w
 
        'Attachments HashTable
        Dim Attachments() As String = File.ReadAllLines("Path\Attachments.txt")
        For Each a As String In Attachments
            HTAttachments.Add(a.GetHashCode, a)
        Next a
 
        'Get the part of the Logfile to check (assumes the _mp was stripped from the end)
        Dim LogString As String = "ak47_ft"
 
        'Get a list of the weapons/attachments in order of appearance within the log string
        Dim Results As List(Of String) = SearchLog(LogString, "_"c)
 
        For Each s As String In Results
            MsgBox(s)
            's will either be wrapped in <Weapon></Weapon> or <attachment></attachment> tags now so you can easily figure out the order etc.
        Next
    End Sub
 
    Private Function SearchLog(ByVal LogInput As String, ByVal SplitChar As Char) As List(Of String)
        Dim Results As New List(Of String)
 
        Dim StartIndex As Integer = 0
        Dim NextSplitChar As Integer = LogInput.IndexOf(SplitChar)
        If NextSplitChar = -1 Then
            'No underscores means that we should be looking at a weapon
            Results.Add(HTWeapons.Item(LogInput.GetHashCode))
            Return Results
        End If
 
        Do While True
            'As the maximum number of underscores in any weapon/attachment is 3
            'control upto how many underscores to look past when creating a substring
            For i As Integer = 0 To 3
                Dim GetSubString As String = LogInput.Substring(StartIndex, NextSplitChar - StartIndex)
                Dim HashCode As Integer = GetSubString.GetHashCode
                If HTWeapons.ContainsKey(HashCode) Then
                    'Weapon found in log
                    Results.Add("<Weapon>" & HTWeapons.Item(HashCode) & "</Weapon>")
                    StartIndex = NextSplitChar
                    Exit For
                ElseIf HTAttachments.ContainsKey(HashCode) Then
                    'Attachment found in log
                    Results.Add("<Attachment>" & HTAttachments.Item(HashCode) & "</Attachment>")
                    StartIndex = NextSplitChar
                    Exit For
                Else
                    'Nothing found, extend substring to include chars upto the next splitchar occurence
                    If NextSplitChar >= LogInput.Length Then Exit Do
                    NextSplitChar = LogInput.IndexOf(SplitChar, NextSplitChar + 1)
                    If NextSplitChar = -1 Then NextSplitChar = LogInput.Length
                End If
            Next i
            'When a result is found, reset the startindex so we can look for the next weapon/attachment in the string
            If NextSplitChar >= LogInput.Length Then Exit Do
            StartIndex = NextSplitChar + 1
            NextSplitChar = LogInput.IndexOf(SplitChar, StartIndex)
            If NextSplitChar = -1 Then NextSplitChar = LogInput.Length
        Loop
 
        Return Results
 
    End Function
 
End Class

And here's the contents of the files

Attachments.txt:

VB Code:

acog
reflex
drum
dualclip
elbit
extclip
ft
gl
grip
ir
upgradesight
lps
mk
speed
rf
silencer
snub
vzoom
dw
auto

Weapons.txt (There were 3 attachments in the original list that I have removed):

VB Code:

ak47
ak74u
asp
aug
knife_ballistic
china_lake
m1911
commando
crossbow_explosive
cz75
dragunov
enfield
famas
fnfal
g11
galil
hk21
hs10
ithaca
kiparis
knife
l96a1
m14
m16
m60
m72_law
mac11
makarov
mp5k
mpl
pm63
psg1
python
rottweil72
rpg
rpk
skorpion
spas
spectre
stoner63
strela
uzi
wa2000
concussion_grenade
flash_grenade
frag_grenade
sticky_grenade
tabun_gas
willy_pete
airstrike
auto_gun_turret
cobra_20mm_comlink
dog_bite
hind_minigun_pilot_firstperson
huey_minigun_gunner
m220_tow
mortar
napalm
rcbomb
claymore
satchel_charge
hatchet
explosive_bolt
explodable_barrel
hind_rockets_firstperson
minigun_mp
m202_flash

Hope this helps :)

Re: Parsing concatenated string

You can possibly clean up your code if you change the order you check things.

Split the array and check the first string to see if the first string is a weapon part. (20 possible strings(Hind, M202, m72 ect.))
If it is a weapon part the whole sting is a weapon with no attachments.
Condition 5 ,6 or 7.

Then it becomes easy to deal with the rest.

Check the Array length.
Result 2 = Condition 1
Result 4 = condition 4

Result 3
Check first string in the array for attachment. (2 possible Strings(ft, gl))
If attachment then condition 3

else condition 2.

You could speed this up a little by checking Condition 1 first, then Condition 3 Length array(0) is 2, Then (5,6,7). Then pick up condition 4and 2.

Re: Parsing concatenated string

I wrote a quick sub that i think will meet your needs. If you call Get_Weapon with your log file weapon string you can use WeaponStr, Attach1Str and Attach2Str as the values for your database. I added AttackKill as an attachment kill flag if you want to use it

I appears that FT and GL are your only Attachment Kills so this should work. If this is not the case we can modify this slightly to deal with other attachment kills.

I wrote the WeapPart check as a string for simplification. You can modify this to read the weap part strings from your database or a text file if you like.

Code:

Dim WeaponStr As String Dim Attach1Str As String Dim Attach2Str As String Dim AttachKill As Boolean Public Sub Get_Weapon(ByVal ReadStr As String) Dim ReadArr As Array Dim WeapPart As String Dim WeapPartArr As Array Dim I As Integer 'Set Variables WeaponStr = "" Attach1Str = "" Attach2Str = "" AttachKill = false WeapPart = "auto,china,cobra,concussion,crossbow,dog,explodable,explosive,flash,frag,heuy,hind,knife,m202,m220,m72,minigun,satchel,sticky,tabun,willy" ' Read Log String ReadArr = Split(ReadStr, "_") ' Condition 1 If ReadArr.Length = 2 Then WeaponStr = ReadArr(0) Exit Sub End If ' Condition 3 If ReadArr(0).length = 2 Then WeaponStr = ReadArr(1) Attach1Str = ReadArr(0) AttachKill = true Exit Sub End If ' Condition 5, 6, 7 WeapPartArr = Split(WeapPart, ",") For I = 0 To 20 If ReadArr(0) = WeapPartArr(I) Then WeaponStr = Replace(Microsoft.VisualBasic.Left(ReadStr, (Len(ReadStr) - 3)), "_", " ") Exit Sub End If Next 'Condition 2 If ReadArr.Length = 3 Then WeaponStr = ReadArr(0) Attach1Str = ReadArr(1) Exit Sub End If 'Condition 4 If ReadArr.Length = 4 Then WeaponStr = ReadArr(0) Attach1Str = ReadArr(1) Attach2Str = ReadArr(2) Exit Sub End If End Sub

Re: Parsing concatenated string

Thanks, I'll take a look at these, looks better than my idea's. There is one other attachment kill: mk (masterkey, which is an underbarrel shotgun).

Re: Parsing concatenated string

That code should be able to handle MK with no changes.

Fortunately, all three of your attachment kills start with 2 digit strings.

Re: Parsing concatenated string

Thanks guys. There were a few technicalities that required fixing but that was easy enough. So far I have not encountered any problems with it so it seems to work fine :)