Removing the last characters from a string

[Dann Morgan]

Afternoon,

I am trying to shorten a file name, so that it omits the last 4 characters. I am using Stata 14.

The data files have names such as: 200112dvb.dta, 20013ascasde.dta, 20013gbfer.dta

The code I am using is:

local years 2001 2002
foreach year of local years{
cd "dir"
local files : dir . files "`year'*.dta"
foreach f of local files {
disp "`f'"
local file = substr("`f'", 1, length(`f')-4)
}
}

However, the code I am using returns an error r(198). In particular, it says 200112dvb: operator invalid.

Any assistance would be much appreciated.

[Junie Joseph]

Hi Dann,

I believe your issue is because you are using the command length instead of the command strlen. Try that and let me know of your results!

Junie

[Dann Morgan]

Thanks Junie. Unfortunately I still get the same error message.

[Mike Lacy]

You need double quotes around the dereferenced local `f' given as an argument to length(), which expects a string.

local file = substr("`f'", 1, length("`f'")-4)

[Nick Cox]

You need " " around each mention of the local macro f. Otherwise you're trying to work with the macro name, not its contents.

[Junie Joseph]

That is it! Sorry, I forgot to mention that as well. It's nice to know that length should also work in addition to strlen. Thanks Mike and Nick.

[Dann Morgan]

Many thanks.