C managing configuration

[Харбин Хэйлунцзян]

I need to keep some data in configuration files to initialize it at the start of my program and to save some in between its runs. As I understand it the convention is to keep such data in files with the .config extension. There must be some standard API for reading from and changing data in such files. I would appreciate it if someone pointed me into the right direction.

 

[covacat]

maybe in some desktop env stuff but traditional unix had an /etc/argv[0].rc maybe and .argv[0]rc and the api was something like fputs and fgets

 

[SirDice]

configuration files to initialize it at the start of my program

/usr/local/etc/myapp.conf

and to save some in between its runs.

/tmp/myapp/
/var/tmp/myapp/
/var/run/myapp/
/var/db/myapp/
/var/cache/myapp/
Depending on the type of data.

As I understand it the convention is to keep such data in files with the .config extension.

Unix never used or cared about file extensions. They are for a user's convenience, not the computer's. It really doesn't care what you name it. This whole idea of extensions is a product from the CP/M MS-DOS era (and everything that's been based on that).

There must be some standard API for reading from and changing data in such files.

Everything is a file. That's the standard API.

 

[Kai Burghardt]

[…] There must be some standard API for reading from and changing data in such files. […]

libucl(3) – not standard as in “available everywhere”, but in the long‑term to be standard to configure the FreeBSD base system. See also Thread 92016 [for some strange reason as of 12/08/25 21:25Z inaccessible] (Thread 67720 just for ini‑style files).​

 

[Харбин Хэйлунцзян]

Thanks to everyone for responding. I'll try to digest this.