trim .txt off of file names

[RCR1991]

Hi,

I read a list of files all w/ .txt extension. Program I am passing that info to needs to have just the filename passed to it, not the extension. Been searching the archives here and found this copy command pasted below--but I don't completely understand the syntax.

Code:
//code to read file list
GetFileList>D:\AOK_5_1_06_CHART\test\*.txt,files
Separate>files,;,file_names

Let>k=0
Repeat>k
Let>k=k+1

Let>fn2={copy(file_names_%k%,4,length(file_names_%k%)-4)}
Message>%fn2%

Label>end
//Until>k,file_names_count

The lines in bold above are what I am stuck on.

Purpose is to get a newvar (fn2) to hold the value of the variable file_names - last 4 characters. The copy command was deep in a thread about this sort of text manipulation, and I believe was submitted by one of the MJT folk. But I cannot find documentation on the syntax so....help how to make this work?

TIA

Rob

[Marcus Tettmar]

That syntax is wrong and in any case starts from the 4th character. You want this:

Let>filename=file_names_%k%
Let>filename={copy(%filename%,1,length(%filename%)-4)}

E.g. try this example on it's own:

Let>filename=somefile.txt
Let>filename={copy(%filename%,1,length(%filename%)-4)}
MessageModal>filename

You will see that the outcome is somefile without the .txt

How does it work? Read the Complex Expressions topic in the help file. In there you will see topics for the copy and length functions.

Length returns the length of a string, so in this case Length(%filename%) returns the length of somefile.txt = 12. Copy extracts x chars from some string starting from position n. In this case the string is filename, the starting position is the first char (1) and the number of chars to extract is the length of filename - 4 = 8 characters. 1 to 8 is somefile. .txt is 4 you see.

So all it is is the two functions combined. The following is the same in longer form but easier to read:

Let>filename=somefile.txt
Let>len_filename={length(%filename%)}
//len_filename should now equal 12
Let>filename={copy(%filename%,1,%len_filename%-4)}

Hope this explains it.