topic Re: Edición de la expresión de campo de AutoCAD o edición de expresiones diésel - Insertar archivo in AutoCAD Forum

Editing AutoCAD Field Expression or Diesel expression editing - Insert file name

Anonymous — Fri, 22 Mar 2019 18:07:36 GMT

How would you enter a file name but remove the last four characters?

For example, after typing field in AutoCAD, you can grab the field expression string:

%<\AcVar Filename \f "%tc1%fn2">%

Which will add the file name.

How can you do this but remove the last four characters:

WL-A-XYZ_R1A would become WL-A-XYZ

So I dont have the revision R1A displayed

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

rkmcswain — Fri, 22 Mar 2019 18:20:47 GMT

You can use this DIESEL expression.

$(substr,$(getvar,dwgname),1,$(-,$(strlen,$(getvar,dwgname)) ,8))

Which means the field code string will be:

%<\AcDiesel $(substr,$(getvar,dwgname),1,$(-,$(strlen,$(getvar,dwgname)) ,8))>%

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

Anonymous — Fri, 22 Mar 2019 18:27:00 GMT

You can try this:

$(substr,$(getvar,"dwgname"),1,8)

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

rkmcswain — Fri, 22 Mar 2019 18:44:07 GMT

@Anonymous wrote:
You can try this:
$(substr,$(getvar,"dwgname"),1,8)

That only works if the portion of the file name you want to retain is eight characters long.

See above, where that DIESEL statement reads the entire file name, no matter what the length, and removes the last eight characters, which is the four character suffix and the four characters ".DWG"

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

Anonymous — Fri, 22 Mar 2019 18:53:45 GMT

@rkmcswain Exactly!! My expression goes from character 1 to 8, since its name is 12 it will remove the last 4.

His expression got much better

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

rkmcswain — Mon, 25 Mar 2019 11:52:06 GMT

@Frjuniornogueira wrote:

Exactly!! My expression goes from character 1 to 8, since its name is 12 it will remove the last 4.

That makes little sense. Why hardcode something to only work in one particular case, when it can be written so that it works in multiple scenarios?

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

Anonymous — Thu, 28 Mar 2019 15:04:40 GMT

True, but how do you add that extra feature in the code?

Re: Edición de la expresión de campo de AutoCAD o edición de expresiones diésel - Insertar archivo

Anonymous — Thu, 19 Nov 2020 10:14:21 GMT

¿Cuál sería la cadena para eliminar los caracteres "x" delante y "x" detrás. ¿Sin tener en cuenta la longitud del nombre de archivo? Gracias

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

neabailey — Wed, 09 Mar 2022 17:00:21 GMT

@rkmcswain This has been super helpful. Is there a way to remove the first 4 characters instead of the last 4? For example making file name WSS-titleblock-01.dwg look like titleblock-01.dwg.

~nic

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

dvicarioXT — Fri, 20 May 2022 06:11:28 GMT

That should be easier, try this:

$(substr,$(getvar,dwgname),5)

Where 5 is the position of the first character you pick. You can also exclude a certain amount of characters from the start AND the end, but it's a bit more complex (I'm not an expert, maybe there's a better way to do that):

$(substr,$(getvar,dwgname),5,$(-,$(strlen,$(getvar,dwgname)),8))

You take away 4 from the beginning (so you start with the 5th character) and 4 (8-4=4) from the end.

I hope that helps

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

cadffm — Fri, 20 May 2022 06:43:22 GMT

deleted ~superfluous~

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

ryan_gajelomo — Fri, 01 Aug 2025 05:48:32 GMT

@rkmcswain can you help me with this? i am trying to get only the "ceiling light feature detail" only. but the last 11 characters are not removed.

this is the filename:

MDGI_MDG_L1_A0_X1.1.406_CEILING LIGHT FEATURE DETAIL_250801.dwg

and i used this diesel expression:

$(substr,$(getvar,dwgname),25,$(-,$(strlen,$(getvar,dwgname)) ,11))

i am trying to get only the "ceiling light feature detail". but the last 11 characters are not removed.

did i failed at somepoint? any help is much appreciated. thank you!

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file

cadffm — Fri, 01 Aug 2025 07:17:03 GMT

Hi,

and the part starts always with character 25 and ends 11 befor end ??

Substr , "string" , start character nr, length

String: dwgname

Start: 25

Length: full length - 24 - 11

Your "length" part should be:

$(-,$(strlen,$(getvar,dwgname)),35)

Untested

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file name

ryan_gajelomo — Fri, 01 Aug 2025 08:12:36 GMT

hi, thanks for your reply. to answer your question, yes, it always begins with 25th character.

after searching for some time, i somewhat found a solution to my query. i forgot to save the link where i found it, but i think it's from cadtutor.

Here's what he/she did:

$(substr,$(substr,$(getvar,"dwgname"),1,$(-,$(strlen,$(getvar,"dwgname")),11)),25)

wherein it gets the whole string length that begins with the 25th character and subtract 11 last characters.

from filename: MDGI_MDG_L1_A0_X1.1.406_CEILING LIGHT FEATURE DETAIL_250801.dwg

result:

it also works for my other files as well:

from filename: MDGI_MDG_L1_A0_X1.1.101_PARTITION WALL FINISH PLAN_250731

result:

as of the moment, that query of mine is kinda solved.

what i'm having right now is this:

some of the filenames has (example: X1.1.301a).

now, i'm wondering how am i going to add-in the "a" without ruining the result.

please help. many thanks!

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file name

cadffm — Fri, 01 Aug 2025 09:01:12 GMT

Hi,

>"as of the moment, that query of mine is kinda solved."

Glad to help

My DIESEL line would be: $(substr,$(getvar,dwgname),25,$(-,$(strlen,$(getvar,dwgname)),35))

>>"what i'm having right now is this: "

So, A sample filename could be: MDGI_MDG_L1_A0_X1.1.406aCEILING LIGHT FEATURE DETAIL_250801.dwg

Thats unusual, but otherwise your "always from 25" statement is wrong.

Let's see:

substr of DWGNAME

start with char 16

length: IF char 24 is "_", then length is 8, else length is 9

Take a look to the DIESEL catalog and IF function [F1]

$(substr,$(getvar,dwgname),16,$(if,$(eq,_,$(substr,$(getvar,dwgname),24,1)),8,9))

Re: Editing AutoCAD Field Expression or Diesel expression editing - Insert file name

simone_tiezza — Tue, 21 Oct 2025 14:01:20 GMT

Hi,
is there a way to set a character as a "break" in my filename? For example my filename is Test01_02x.dwg and from the expression I would like to get only 02x, so "_" is my break character. My file names have different length but the same syntax (XXXX_YYY)

Thanks a lot