This is sysinfo/t_uname.c (Listing 12-2, page 230), an example from the book, The Linux Programming Interface.

The source code file is copyright 2022, Michael Kerrisk, and is licensed under the GNU General Public License, version 3.

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/* t_uname.c

   Demonstrate the use of the uname() system call, which returns various
   identifying information about the system.
#ifdef __linux__
#define _GNU_SOURCE
#include <sys/utsname.h>
#include "tlpi_hdr.h"
main(int argc, char *argv[])
    struct utsname uts;

    if (uname(&uts) == -1)

    printf("Node name:   %s\n", uts.nodename);
    printf("System name: %s\n", uts.sysname);
    printf("Release:     %s\n", uts.release);
    printf("Version:     %s\n", uts.version);
    printf("Machine:     %s\n", uts.machine);
#ifdef _GNU_SOURCE
    printf("Domain name: %s\n", uts.domainname);


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