What is libg2c library?
g++, gcc, libraries, linux
Solution
What is GNU Fortran?
`g77` consists of several components:
A modified version of the `gcc` command, which also might be installed as the system's `cc` command. (In many cases, `cc` refers to the system's “native” C compiler, which might be a non-GNU compiler, or an older version of `gcc` considered more stable or that is used to build the operating system kernel.)
The `g77` command itself, which also might be installed as the system's `f77` command.
The `libg2c` run-time library. This library contains the machine code needed to support capabilities of the Fortran language that are not directly provided by the machine code generated by the `g77` compilation phase.
`libg2c` is just the unique name `g77` gives to its version of `libf2c` to distinguish it from any copy of `libf2c` installed from `f2c` (or versions of `g77` that built `libf2c` under that same name) on the system.
You may think of it as, `libg2c` is to `g77` as `libc` is to `gcc`.
Note that as of the GCC 4.x series, `g77` has been discontinued, replaced by gfortran, which produces programs that do not require an extra `libg2c` runtime library.
Problem
I have found the code which links against of 'g2c' library. Why do I need it? Just would like to understand why it might be important and what it does in general. Thanks!