I have sore throat, headache, bodyache, mild fever. is it a bacterial or viral infection?

Hard to say: It could be either. Your doctor can perform a throat swab and do a test on the sample to rule out a bacterial strep infection.

Could be either: Those symptoms actually can go with either a bacterial or viral infection. Strep throat is a possible bacterial cause of those symptoms. There could be several viruses causing this as well. Someone with mild symptoms could start with supportive care with fever reducer, fluids, and rest. If symptoms worsened or did not improve, one should be examined and have a strep test done.

More commonly viral: Viral infections are much more common and likely causing your symptom complex, but it is difficult to tell for sure. If your throat is red, with pus, and swollen, you should have it checked for possible strepthroat. Otherwise, viral is likely and symptoms will get better in a few days. Motrin/tylenol, and sorethroat spray to help your symptoms. Consult doc if you get worse. Good luck.