Strange result of SysUtils.ExtractRelativePath

[AlexTP]

Code: Pascal  [Select][+][-]

1. uses sysutils;
2. begin
3.   Writeln(ExtractRelativePath('/home/a/b/file.json', 'name.json'));
4. end.
5.  

Prints

../../../name.json

I am not sure it's ok result.
Maybe FPC pre-3.2 gave another result, cannot check now.

user@PC:~/fpcupdeluxe/fpcupdeluxe32/fpc/bin/x86_64-linux$ ./fpc
Free Pascal Compiler version 3.2.3-556-gc0f20e0e5f-dirty [2021/11/28] for x86_64

[Bart]

Maybe FPC pre-3.2 gave another result, cannot check now.

Same result for 3.0.4 and trunk.
So, if it is a bug, at least it's consistent.

Bart

[WooBean]

Hi,
from LHelp we have:

"function ExtractRelativePath(const BaseName: UnicodeString;  const DestName: UnicodeString):UnicodeString;
...
Note that directories must end on a path delimiter for this function to work correctly. If not, the last part is stripped and treated as a file name. "

So, there is no bug.

[Kays]

ExtractRelativePath expects two absolute paths (or at least two starting from the same directory). If name.json was in the same directory as file.json, the “relative” path name.json is already the relative path you intend to extract, so you using this routine is pointless.