How to distinuguish between Fedora/centOS and Debian/Ubuntu OS in Qt5

Ryna

Hi,
My application needs to support Linux (Ubuntu and Fedora). Which is the best way/MACRO to differentiate between Ubuntu and Fedora OS in Qt5?
Thanks for your help.

jeremy_k

There might be a file /etc/os-release that contains sh style variable assignments. For example:

NAME="Ubuntu"
VERSION="20.04.2 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.2 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

ID and VERSION_ID seem to exist reliably in the distros I've looked at (Ubuntu, Debian, Fedora, OpenSUSE, and vendor supported versions of these). There are lots of variables that are distribution-specific.

QSysInfo will use this file, at least in the version of the Qt source I'm looking at. QSysInfo::productType() might be a reasonable choice for this purpose.

Kent-Dorfman

There is no linux requirement for distros to identify themselves so any attempt will be ad-hoc. I'd suggest writing your app to be distro neutral.

jeremy_k

There might be a file /etc/os-release that contains sh style variable assignments. For example:

NAME="Ubuntu"
VERSION="20.04.2 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04.2 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal

ID and VERSION_ID seem to exist reliably in the distros I've looked at (Ubuntu, Debian, Fedora, OpenSUSE, and vendor supported versions of these). There are lots of variables that are distribution-specific.

QSysInfo will use this file, at least in the version of the Qt source I'm looking at. QSysInfo::productType() might be a reasonable choice for this purpose.

ChrisW67

Jeremy_k has a run-time answer that may work.

Differentiating at compile time (i.e. with a macro) is not feasibly simply because the build machine and the run time machine are not the same.

@Ryna Why do you need to tell the two apart? What will you do differently?

JonB

@Ryna
Purely OOI, why do you need to distinguish between these distros? If, say, you want to run apt under Debian I would just test whether /usr/bin/apt is present,

Otherwise uname -a gives what information is available. I presume you can access what you want from that via uname() (man 2 uname) as a system call from code.

raven-worx

@Ryna
see QSysInfo class and inspect its properties

Ryna

@raven-worx yes, I checked that. productVersion can help me. Thank you

Ryna

@jeremy_k Thank you. Yes that has worked.

JoeCFD

Try this env to see if it helps.
echo $DESKTOP_SESSION

Ryna

@ChrisW67 said in How to distinuguish between Fedora/centOS and Debian/Ubuntu OS in Qt5:

@Ryna Why do you need to tell the two apart? What will you do differently?

I need to use dpkg that needs me to distinguish between two distros.

JonB

@Ryna said in How to distinuguish between Fedora/centOS and Debian/Ubuntu OS in Qt5:

I need to use dpkg that needs me to distinguish between two distros.

So why not test for whether dpkg is present?

JoeCFD

@JonB what if it is not installed?

JonB

@JoeCFD
First it would be pretty odd for a Deb not to have dpkg, so far as I know.

The OP seems to want to run dpkg. If it's Deb but not available he can't run it, just like under Fed. I don't see what you gain by trying to look for some product type in this situation. Up to the OP.

Ryna

@JonB Packages which I am able to install on mint, same package I was unable to install on fedora. Looks like I need to take different version of package for both distros. Fedora and Mint versions are constant and can't be changed so I can pick up package based on this differentiation I guess.