String trimming for output format - fortran

Question

This is my code:
Program String_Triming
Implicit none
Open(15, File = 'Output.txt')
Write(15,'(A,1x,"j",1x,A)') Ispis(20.45),Ispis(20.45)
Write(15,'(A,1x,"j",1x,A)') Ispis(-20.45),Ispis(-20.45)
Close(15)
Contains
Function Ispis ( Deg ) result ( Str )
Real,intent(in)::Deg
Character(len=16):: Str
If ( Deg > 0 ) then
Write(Str,'(F0.3)') 1000.0 + Deg
Str = Str(2:)
Else
Write(Str,'(F8.3)') 1000.0 + abs(Deg)
Write(Str,'("-",A)') Str(3:)
End If
End Function Ispis
End program String_Triming
The content of Output.txt file is:
020.450 j 020.450
-20.450 j -20.450
The result I want to get from this code is:
020.450 j 020.450
-20.450 j -20.450
How do I get that result? Is there way to trim the length of Str to Len=8 which is the length of 020.450?

Answer 1

It's not quite clear what you want. If all you want is to remove the spaces from the output file, why not just run it through sed instead of writing a Fortran Program:
$ cat Output.txt
020.450 j 020.450
-20.450 j -20.450
$ sed -r 's/ +/ /g' Output.txt
020.450 j 020.450
-20.450 j -20.450
If you want to produce output like this in the first place, you could 'overwrite' the first three characters of str with an integer format. Something like this:
function Ispis(Deg) result(Str)
real, intent(in) :: Deg
character(len=7) :: Str
write(Str, '(F7.3)') Deg
if ( Deg < 0 ) then
write(Str(:3), '(I3.2)') int(Deg)
else
write(Str(:3), '(I3.3)') int(Deg)
end if
end function Ispis
note: the length of 020.450 is 7, not 8.

Answer 2

This is the solution for getting wanted result:
Program Main
Implicit none
Open(15,File='Output.txt')
Write(15,'(1x,a,1x,"j",1x,a,1x,"Juhu!")') Writing_01(67.45),Writing_01(-4.04)
Write(15,'(1x,a,1x,"j",1x,a,1x,"Juhu!")') Writing_02(67.45),Writing_02(-4.04)
Close(15)
Contains
Function Writing_01 ( Deg ) Result ( Str )
Real,intent(in) :: Deg
Character(:),allocatable :: Str
Character(len = 15 ) :: Str_temp
If ( int( Deg ) > 0 ) then
Write(Str_temp , '(F0.2)' ) 100000.0 + Deg
Str_temp = Str_temp(2:)
Else
Write(Str_temp, '(F0.2)' ) 100000.0 + abs(Deg)
Str_temp = "-"//Str_temp(3:)
Endif
Str = trim ( adjustl ( Str_temp ))
End Function Writing_01
Function Writing_02 ( Deg ) Result ( Str_temp )
Real,intent(in) :: Deg
Character(:),allocatable :: Str_temp
Character(len=1561) :: Form_02 , Res
If (int( Deg ) > 0 ) then
Form_02 = '(i5.5,f0.2)' ! allow a total of 4 leading zeros.
Else
Form_02 = '(i5.4,f0.2)' ! "-" sign takes up one space, so 3 leading zeros remain.
Endif
Write(Res , Form_02 ) int( Deg ), abs( Deg - int( Deg ) )
Str_temp = trim ( adjustl ( Res ))
End Function Writing_02
End program Main