How can my C/C++ application determine if the root user is executing the command?

Question

I am writing an application that requires root user privileges to execute. If executed by a non root user, it exits and terminates with a perror message such as:

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Answer 1

I would recommend NOT making this change, but instead improving your error message. It's doubtful that your application actually needs to "be root"; instead it needs certain privileges which root has, but which operating systems with fine-grained security controls might be able to grant to the application without giving it full root access. Even if that's not possible now, it may be possible 6 months or 2 years from now, and users are going to be irritated if your program is refusing to run based on backwards assumptions about the permission model rather than just checking that it succeeds in performing the privileged operations it needs to.