wsh(Windows Scripting Host), String length limit on Windows Scripting Host Run method

String length limit on Windows Scripting Host Run method

Author	Message
rcalder #1 / 13	String length limit on Windows Scripting Host Run method Does anyone know if there is a string length limit to the command line you pass into the Windows Scripting Host .Run method? Our app dynamically builds the string to pass in but sometimes (when the string is quite long) it generates an error.
Wed, 20 Jul 2005 04:14:50 GMT

MVP #2 / 13	String length limit on Windows Scripting Host Run method Quote: > Does anyone know if there is a string length limit to the command line > you pass into the Windows Scripting Host .Run method? > Our app dynamically builds the string to pass in but sometimes (when > the string is quite long) it generates an error. It's a limitation of the OS, not the Run method. I've never been able to find any official documentation, but past posts and personal observation indicates that it's somewhere around 1K. -- Michael Harris Microsoft.MVP.Scripting Seattle WA US
Wed, 20 Jul 2005 10:42:11 GMT

Lee #3 / 13	String length limit on Windows Scripting Host Run method Quote: >Does anyone know if there is a string length limit to the command line >you pass into the Windows Scripting Host .Run method? >Our app dynamically builds the string to pass in but sometimes (when >the string is quite long) it generates an error. This test case generates errors when the argument length is greater than 2001 characters: <html> <head> <script type="text/javascript"> function launch(count){ var arg="X"; while(arg.length<count) arg+=arg; arg=arg.substr(0,count); var Shell=new ActiveXObject("WScript.Shell"); Shell.Run("myHTA.hta "+arg); } </script> </head> <body> <form> <input name="count" value="1000"> <input type="button" value="launch" onclick="launch(this.form.count.value)"> </form> </body> </html> myHTA.hta is simply: <html> <head> <HTA:application id="myHTA"> </head> <body> <script type="text/javascript"> var arg=myHTA.commandLine.replace(/^.* X/,"X"); document.write("I see "+arg.length+" characters."); </script> </body> </html>
Wed, 20 Jul 2005 06:43:27 GMT

larrydaloo #4 / 13	String length limit on Windows Scripting Host Run method Quote: > Does anyone know if there is a string length limit to the command line > you pass into the Windows Scripting Host .Run method? > Our app dynamically builds the string to pass in but sometimes (when > the string is quite long) it generates an error. Generally, I would think 512 chars, but the command line limit is 32767 I dunno
Wed, 20 Jul 2005 11:45:53 GMT

MVP #5 / 13	String length limit on Windows Scripting Host Run method 2046 characters, but in practice you have to account for quoting and full paths with everything used if you are using drag-drop... -- Please respond in the newsgroup so everyone may benefit. http://dev.remotenetworktechnology.com (email requests for support contract information welcomed) ---------- Subscribe to Microsoft's Security Bulletins: http://www.microsoft.com/technet/security/bulletin/notify.asp Quote: > > Does anyone know if there is a string length limit to the command line > > you pass into the Windows Scripting Host .Run method? > > Our app dynamically builds the string to pass in but sometimes (when > > the string is quite long) it generates an error. > It's a limitation of the OS, not the Run method. I've never been able to > find any official documentation, but past posts and personal observation > indicates that it's somewhere around 1K. > -- > Michael Harris > Microsoft.MVP.Scripting > Seattle WA US
Fri, 22 Jul 2005 00:19:41 GMT

MVP #6 / 13	String length limit on Windows Scripting Host Run method That length (32767) is the upper limit to the buffer length I think. In other words, the command line _should_ be able to take that many characters; the problem is that only 2K or so gets passed on to an app via the shell. -- Please respond in the newsgroup so everyone may benefit. http://dev.remotenetworktechnology.com (email requests for support contract information welcomed) ---------- Subscribe to Microsoft's Security Bulletins: http://www.microsoft.com/technet/security/bulletin/notify.asp Quote: > > Does anyone know if there is a string length limit to the command line > > you pass into the Windows Scripting Host .Run method? > > Our app dynamically builds the string to pass in but sometimes (when > > the string is quite long) it generates an error. > Generally, I would think 512 chars, but the command line limit is 32767 > I dunno
Fri, 22 Jul 2005 00:22:49 GMT

Joe Earnes #7 / 13	String length limit on Windows Scripting Host Run method Hi Alex, I think you're right. I believe that the 32K is a settable buffer for DOS 7.1 (Win9x) and otherwise for the command processor, not for the handling of files within the main Windows GUI itself. I have always assumed that the same limits apply as apply to running files variously in the Run box or shortcuts and, more particularly, from the registry shell commands (which I have also assumed to be the same handler as used by Shell and Shell.Application to run files). My best guess anyway. Regards, Joe Earnest \| That length (32767) is the upper limit to the buffer length I think. In other \| words, the command line _should_ be able to take that many characters; the \| problem is that only 2K or so gets passed on to an app via the shell. --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.410 / Virus Database: 231 - Release Date: 10-31-02
Fri, 22 Jul 2005 01:17:22 GMT

Joe Earnes #8 / 13	String length limit on Windows Scripting Host Run method Hi, Do you have a reference for the 2046. I've looked but never found a precise statement. (I probably overlooked something obvious, as usual.;-) Regards, Joe Earnest \| 2046 characters, but in practice you have to account for quoting and full paths \| with everything used if you are using drag-drop... --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.410 / Virus Database: 231 - Release Date: 10-31-02
Fri, 22 Jul 2005 01:19:39 GMT

MVP #9 / 13	String length limit on Windows Scripting Host Run method Two or three arguments/discussions in win2000.cmdprompt.admin, and checking it out myself. There seems to be something different which happens with tools such as the exec method, and drag-drop onto an open object is exempt as well. For prior discussions, look for the following type of info. + Heaviest group os microsoft.public.win2000.cmdprompt.admin + "Magic numbers" which show up for different OSs and different shells are 127, 260, 2046, 2047, 2048. + Hot terms are "command tail", "command tail length", "console buffer". Phil Robyn, Marty List, Joe Richards, Dean Wells, Jonathan deBoyne Pollard, and myself have participated in some of the past discussions. -- Please respond in the newsgroup so everyone may benefit. http://dev.remotenetworktechnology.com (email requests for support contract information welcomed) ---------- Subscribe to Microsoft's Security Bulletins: http://www.microsoft.com/technet/security/bulletin/notify.asp Quote: > Hi, > Do you have a reference for the 2046. I've looked but never found a precise > statement. (I probably overlooked something obvious, as usual.;-) > Regards, > Joe Earnest > \| 2046 characters, but in practice you have to account for quoting and full > paths > \| with everything used if you are using drag-drop... > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.410 / Virus Database: 231 - Release Date: 10-31-02
Fri, 22 Jul 2005 01:36:35 GMT

MVP #10 / 13	String length limit on Windows Scripting Host Run method Quote: > Hi Alex, > I think you're right. I believe that the 32K is a settable buffer for DOS > 7.1 (Win9x) and otherwise for the command processor, not for the handling of > files within the main Windows GUI itself. I have always assumed that the > same limits apply as apply to running files variously in the Run box or > shortcuts and, more particularly, from the registry shell commands (which I > have also assumed to be the same handler as used by Shell and > Shell.Application to run files). My best guess anyway. I tried this out with one script calling another script using an arbitrary command line length with the Exec method. The calling script, Tweedledum.vbs, used the exec method to explicitly call "c:\windows\system32\cscript.exe C:\tmp\tweedledee.vbs " adding a string of "x" characters. Tweedledee then wrote the argument length to a text file. The last length it got before I errored out was 32710; when you add that to the 55-character length of the base string above, you get 32765. Arguments appear to get explicit quotes wrapped around them when passed in, so this comes to 32767. Since strings are usually terminated with a null character in API methods, this gives us our 32768-character limit for direct transfer. Note that when I switched to using Sh.Run and dropped the command to just "tweedledee.vbs", it choked at 2048 characters consistently for the full command line length. ' === tweedledum.vbs === Set Sh = CreateObject("WScript.Shell") basepath = "c:\windows\system32\cscript.exe C:\tmp\tweedledee.vbs " baseLen = Len(basePath) for i = 32755 - baseLen to 33000 - baseLen 'wscript.echo i + baseLen set exec = Sh.Exec(basepath & String(i, "x")) Do While Not Exec.StdOut.AtEndOfStream wscript.sleep 10 Loop wscript.echo exec.stdout.readall wscript.echo exec.stderr.readall next ' === tweedledee.vbs === v = len(WScript.Arguments(0)) AppendLine "c:\tmp\tweedle.log", v Sub AppendLine(FilePath, sData) 'Given the path to a file, will append line sData to it With CreateObject("Scripting.FileSystemObject")._ OpenTextFile(FilePath, 8, True, TristateUseDefault) .WriteLine sData: .Close End With End Sub -- Please respond in the newsgroup so everyone may benefit. http://dev.remotenetworktechnology.com (email requests for support contract information welcomed) ---------- Subscribe to Microsoft's Security Bulletins: http://www.microsoft.com/technet/security/bulletin/notify.asp
Fri, 22 Jul 2005 02:08:05 GMT

MVP #11 / 13	String length limit on Windows Scripting Host Run method Quote: > 2046 characters, but in practice you have to account for quoting and > full paths with everything used if you are using drag-drop... It can also be limited by personal firewall software. My working limit (with {filter}Armor) is 1023. -- Michael Harris Microsoft.MVP.Scripting Seattle WA US
Fri, 22 Jul 2005 05:09:27 GMT

MVP #12 / 13	String length limit on Windows Scripting Host Run method What the{filter}ens causes _that_ to limit it? This is something I don't get. ;) -- Please respond in the newsgroup so everyone may benefit. http://www.--.com/ (email requests for support contract information welcomed) ---------- Subscribe to Microsoft's Security Bulletins: http://www.--.com/ Quote: > > 2046 characters, but in practice you have to account for quoting and > > full paths with everything used if you are using drag-drop... > It can also be limited by personal firewall software. My working limit > (with {filter}Armor) is 1023. > -- > Michael Harris > Microsoft.MVP.Scripting > Seattle WA US
Fri, 22 Jul 2005 07:08:37 GMT

MVP #13 / 13	String length limit on Windows Scripting Host Run method Quote: > What the{filter}ens causes _that_ to limit it? > This is something I don't get. ;) Note that I use {filter}Armor only because it is a corporate requirement in order to make VPN connections to work from home. I used to use ZoneAlarm when I had a choice ;-). {filter}Armor apparently monitors process creation. It must consider a large command line to be virus-like. I've never had it cause a problem with anything real. You and I actually had an NG exchange on this subject where I mentioned this back in Feb 2002 ;-)... Google Groups: View Thread "buffer limits with StdOut when passing a lot of info..." http://www.--.com/ Quote: >>> 2046 characters, but in practice you have to account for quoting and >>> full paths with everything used if you are using drag-drop... >> It can also be limited by personal firewall software. My working >> limit (with {filter*}Armor) is 1023. >> -- >> Michael Harris >> Microsoft.MVP.Scripting >> Seattle WA US -- Michael Harris Microsoft.MVP.Scripting Seattle WA US
Fri, 22 Jul 2005 07:52:00 GMT

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