trim() function behavior

trim() function behavior

I quite often use the trim() function when concatenating string together so that spacing can be controlled (used often for creation filenames for example) however I noticed that if the variable being trimmed is blank none of the strings following are added to the string. Is this expected?


character*20 :: var1,var2,var3
character*132 :: string

var1 = '250.0'
var2 = 'millimetres'
var3 = 'tagline'

string = trim(var1)//' '//trim(var2)//' '//trim(var3)

string would be '250.0 millimetres tagline'

however if:

var2 = ' '

string would be just '250.0'

where I would expect '250.0 tagline'

I've only noticed this recently so may have been introduced in one of the later XE compiler updates.

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For more complete information about compiler optimizations, see our Optimization Notice.

Please report the specific compiler version which exhibits this behavior. Version (32-bit and 64-bit) on Windows prints:

250.0 tagline

I get:

250.0 tagline

in Update 9 (12.1.330)

Please show a complete program that demonstrates the problem and a command prompt log showing the build and run with the bad results.

Retired 12/31/2016

Hi Steve,

I'm running on Update 9 (12.1.330).

After some investigation the problem I flagged up occurs when thevar2 substring has not been initialised at all. This is down to bad programming practice on my part so apologies for that. However I would be interested to know if the behavoir of the function is as expected.

I know that len_trim() function does not like C strings with trailing char(0)/ Should these founctions still work even if they containare NULL characters using the first encountered NULL as the end of the string?

Thanks for your quick response.

TRIM and LEN_TRIM remove blanks only - not other characters. the NUL character has no special meaning in Fortran.

Retired 12/31/2016

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