Michael Van Canneyt wrote:
On Thu, 5 Dec 2013, Dennis Poon wrote:
I tried to read the mac address in the captioned file path.
In terminal, I can simply 'cat' and display the mac address.
In FPC, when I tried to use TFileStream to read it,
FS := TFileStream.Create('/sys/class/net/eth1/address',
fmOpenRead+fmShareDenyWrite);
it raised "stream read error"
home: >./t
00:1f:d0:a2:df:c4
home: >cat t.pp
{$mode objfpc}
{$H+}
uses sysutils, classes;
Var
S : String;
begin
SetLength(S,100);
with TFileStream.Create('/sys/class/net/eth1/address',
fmOpenRead+fmShareDenyWrite) do
try
SetLength(S,Read(S[1],100));
Writeln(S);
finally
free;
end;
end.
Works fine here. Permission problem on your machine maybe ?
Michael.
So, strange.
I tried again and found that it works if I uses BaseUnix and then call
fpRead but not with TFileStream.Read
My interface uses are:
uses
Classes, SysUtils, DB, iniFiles;
My implementation uses:
uses md5, uStrUtils
{$IFDEF UNIX}
,BaseUnix
{$ENDIF}
;
function GetUnixMac(TheDevice : String) : String;
const
UnixPath = '/sys/class/net/%s/address';
var s,
FileName : String;
FS : TFilestream;
Var fHandle : cint;
len : longint;
buffer :string[255];
begin
result := '';
FileName := Format(UnixPath,[TheDevice]);
if FileExists(FileName) then begin
//this fpread will work and give me mac address
fHandle:=fpOpen(FileName,O_RdOnly);
If fHandle > 0 then
try
len := fpRead (fHandle,buffer[1],255);
setlength(Buffer,len);
Log(TheDevice+' Mac:'+buffer);
result := StringReplace(buffer,#10,';',[rfReplaceAll]);
finally
fpClose(fHandle);
end;
{//strange, the following will raise stream read error
FS := TFilestream.Create(FileName, fmOpenRead+fmShareDenyWrite );
try
if FS.Size > 0 then begin
SetLength(s, FS.Size);
FS.ReadBuffer(s[1], FS.Size);
Log(TheDevice+' Mac:'+S);
result := StringReplace(s,#10,';',[rfReplaceAll]);
end;
finally
FreeAndNil(FS);
end;
}
end;
end;
Why your machine works but my does not and has to rely on fpRead instead
of TFileStream???
Dennis
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