Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
I have a C / C++ program which needs to read in a file that may or may not be gzip compressed. I know we can use gzread() from zlib to read in both compressed and uncompressed files – however, I want to use the zlib functions ONLY if the file is gzip compressed (for performance reasons).
So is there any way to programatically detect or check if a certain file is gzipped from C / C++?
There is a magic number at the beginning of the file. Just read the first two bytes and check if they are equal to
0x1f8b.