I have some c source files. Inside, there is multiple comments with '//' style and others with '/* */' style.
I want to change all of them to /* */ to have more uniformity inside my code and also to respect the standard column width.
How can I change all this comments automatically ?
Thank you for reading !

Edit: I just realize that I didn't explain something important. I need to change my comments to make them compatible with C89. The rest of the coding style is already compatible. Just I don't want to delete all comment or to edit all of them manually. And I think it is also an interesting question.
Typically, that would be the job of a code formatter, and you'd need to at least be able to lex C, which is not really something you want to implement in a shell script or awk program.
Instead, for example, clang-format has plenty options to adjust how your comments look, and should be pretty much available on any desktop OS.
Note that using // for one-line comments is actually fine, imho, and you don't gain anything by using the /*  */ syntax for such.
How can I change all // comments into /* */ comments in C language?