Reading a file in C with File Descriptor
c, file, file-descriptor
Solution
When you say "have to use `read()`" I can't tell if that's your understanding of the situation given a file descriptor from `open()` or a restriction on some kind of assignment.
If you have a file descriptor but you're more comfortable with `fscanf()` and friends, use `fdopen()` to get a `FILE *` from your fd and proceed to use stdio.
Internally it uses functions like `read()` into a buffer and then processes those buffers as you read them with `fscanf()` and friends.
Problem
I want to read from a file by using its file descriptor. I can't use its name because of assignment rules. I obtain it by calling `open` and it works fine. At this moment I know that I have to use the `read()` function in order to read from it. My problem is that `read()` function requires as an argument the number of bytes to read, and I want to read a whole line from the file each time, so I don't know how many bytes to read. If i use for example `fscanf()`, it works fine with a simple string and I take back the whole line as I want. So my question is: Is there any function like `fscanf()` which can be called with file descriptor and not with a file pointer?