How you can dig up configuration particulars in your Linux system with getconf

By | August 13, 2021

Linux techniques can report on much more configuration particulars than you possible ever knew have been accessible. The trick is utilizing the getconf command and having an concept what you might be on the lookout for. Be careful although. You would possibly end up a bit overwhelmed with what number of settings can be found.

To start out, let us take a look at a couple of settings that you simply may need anticipated to see to reply  some necessary questions.

For starters, how lengthy can a filename be?

You’ll be able to verify this setting by wanting on the NAME_MAX setting.

The “x” on the finish of the above command appears essential to keep away from an error (unsure why). You too can use the command proven beneath to see the worth. The -a causes getconf to point out all settings and the grep command then selects any settings that begin with “NAME_MAX”.



Is your system a 32- or a 64-bit system?

What number of processes can a person run without delay?

That is the utmost variety of simultaneous processes allowed per person ID. The processes clearly can not use the CPU on the similar time, however that is the quantity that may be lively.

How lengthy can usernames be?

Care to verify this out? When you create a really lengthy username like that proven beneath, you do not run into any issues.

I am unable to think about anybody prepared to kind wherever close to 256 characters to log in. Nonetheless, this reveals that usernames could be ridiculously lengthy if you happen to want them to be.

If you wish to checklist the entire accessible configuration particulars, be ready. It consists of 320 settings.

Here is what the start of the checklist seems to be like with a few of the settings briefly defined:

One comparatively simple approach to get began with getconf is to pick settings from the checklist utilizing grep. Listed below are all of the settings that embody “NAME” of their names:

Among the settings which can be in all probability probably the most related to Linux customers are the maximums outlined for numerous issues just like the file-name most size. Contemplating the settings, I doubt that I do know anybody has ever pushed residence grumbling that he could not create a file with a reputation that included greater than 255 characters. And can the system let you know if you happen to exceed that restrict? You guess it’ll. Here is a take a look at:

One extra character put us over the restrict within the second contact command proven above.

To checklist all of the setting with “MAX” of their names, run a command like this one:

The one actually massive setting close to the underside, ULONG_MAX, is the utmost worth for an object of kind unsigned lengthy int.

Figuring out what every of the 84 MAX settings truly represents is prone to take a while. Some are described in information just like the limits.h file proven beneath.

The limits.h file is supposed to be informative and can’t be used to alter setting values.

Probably the most fascinating issues concerning the getconf command’s output is exhibiting how beneficiant many of the settings truly are and what number of issues on Linux techniques have limits imposed.