On 03/24/2016 09:58 AM, Zhang Freeman wrote: > Hi List! > > I post to ask for the differenced between 'Requires' and 'Requires(pre)' > used in RPM spec file. > > As RPM wiki[1] tells, dependency defined via 'Requires(pre)' should be > fulfilled before installation and can be freely removed after > installation, and 'Requires' should be fulfilled after installation but > before execution. > > However, things won't stick to the script in real life. I find these two > work in the same way. > > Suppose I want to install package A, which depends on package B. RPM > stops the process and warns me the dependency. After B is installed, > installation of A turns to be succeed. Then I remove B, RPM erases both > A and B! No matter it is "Requires(pre)" or "Requires". > > Shouldn't A stay operational after I remove B if I use 'Requires(pre)' ? Well, it should... not sure if the implementation really fully does it that way. Also note, that there might be other dependencies for package B that may prevent the erasure. Also note that dependency solver like yum/dnf/zypper/... may have different idea of what packages to remove than rpm itself (which actually doesn't select packages to remove a t all, but just spits out error messages). Another difficult to spot difference between Requires: and Requires(pre): is package ordering during the installation. In case of circular dependencies rpm give precedence to Requires(pre): dependencies and rather breaks up normal Requires: Florian -- Red Hat GmbH, http://www.de.redhat.com/, Registered seat: Grasbrunn, Commercial register: Amtsgericht Muenchen, HRB 153243, Managing Directors: Paul Argiry, Charles Cachera, Michael Cunningham, Michael O'Neill _______________________________________________ Rpm-list mailing list Rpm-list@xxxxxxxxxxxxx http://lists.rpm.org/mailman/listinfo/rpm-list
