troubles with QFile::setPermissions

[rock37]

hey folks,

i have the following code to test QFile::setPermissions:

  QString fn = QString("%1/%2").arg(_temporary_dir.path(), "test.txt");
  QFile n = QFile(fn);

  QVERIFY(n.open(QFile::ReadWrite));
  QVERIFY(QFile::exists(fn));
  QVERIFY(QFile::setPermissions(fn, {}));

  QFile::setPermissions(fn, QFileDevice::ReadUser);
  QFileDevice::Permissions flags = QFile::permissions(fn);

  QCOMPARE(flags, QFileDevice::ReadUser);

why does this test fails ?

[rock37]

@rock37 i forgot to say that it fails at the last QCOMPARE command.

[SGaist]

Hi,

Why ? Good question
Do you have proper access to that file ?
Do you have the rights to change the permissions to that file ?
What OS are you on ?
Which version of Qt are you using ?
Did you check from somewhere else that the permissions were changed ?
Did you compare the values of the permissions before and after ?
What filesystem are you on ?

[ChrisW67]

@rock37 said in troubles with QFile::setPermissions:

why does this test fails ?

What does the test error message tell you about the flags actually returned?

This is what happens on my machine with a fixed file in /tmp.

********* Start testing of QFileTest *********
Config: Using QtTest library 6.6.2, Qt 6.6.2 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 10.3.1 20210422 (Red Hat 10.3.1-1)), ubuntu 22.04
PASS   : QFileTest::initTestCase()
FAIL!  : QFileTest::test_case1() Compared values are not the same
   Actual   (flags)                : 17408
   Expected (QFileDevice::ReadUser): 1024
   Loc: [/tmp/test/tst_qfiletest.cpp(33)]
PASS   : QFileTest::cleanupTestCase()
Totals: 2 passed, 1 failed, 0 skipped, 0 blacklisted, 0ms
********* Finished testing of QFileTest *********
Press <RETURN> to close this window...

I tested the permissions on the file after the first setPermission() call are as expected.
I tested that the last setPermissions() call reported success.

Regarding the failing test. The actual file:

/tmp$ ls -l /tmp/test.txt 
-r-------- 1 chrisw chrisw 0 Feb 29 07:05 /tmp/test.txt

and the returned value:

17408 is 0x4400 => QFileDevice::ReadOwner | QFileDevice::ReadUser

Please read the warning in the flags QFileDevice::Permissions docs

If you set ReadUser|WriteUser then you get ReadOwner |WriteOwner|ReadUser|WriteUser back.

[rock37]

@ChrisW67 hmm, how can i then test this function ?

[rock37]

@rock37 so that it works on all os's...

[JonB]

@rock37
@ChrisW67 is suggesting you try

QCOMPARE(flags, QFileDevice::ReadOwner | QFileDevice::ReadUser);

And see if that works on all platforms. If it varies you might have to have an OS-specific check, but hopefully it will work.

[rock37]

@JonB it does also fail, i'm atm on the linux platform but it has to work on all platforms.

[JonB]

@rock37 So if that's really the case make your test QCOMPARE() flags vary according to platform behaviour for this.

[ChrisW67]

@rock37 If you are only interested if the ReadUser flag, regardless of platform, is set then only test for that. Something like:

QVERIFY(flags & QFileDevice::ReadUser);