Linux Confstr and uname function _ get C library and kernel information

#include <stdio.h> #include <sys/utsname.h>//unameint main (int argc, char **argv[]) {struct utsname  u; if (uname (&u)! =-1) {printf ("Get the name and information of the current kernel such as the following \ n" "   " sysname:%s\n ""   nodename:%s\n ""   release:%s\n "   "version:%s\n" "   machine:%s\n"   , U.sysname, U.nodename, U.release, U.version, u.machine);} return 0;}

The output is as follows:

Gets the name and information for the current kernel, such as the following sysname:linuxnodename:fesrelease:2.6.32-220.el6.x86_64version: #1 SMP Wed 9 08:03:13 EST 2011machine:x86_64

size_t confstr (int name, char *buf, size_t len);
The CONFSTR function gets the value of a dependent configuration string variable
1. _cs_gnu_libc_version,the GNU C Library VERSION on the This system
2. _cs_gnu_libpthread_version,the POSIX implementation supplied by this C library
3, _cs_path,a value for the PATH variable which indicates where all the POSIX.2 standard utilities can be found.

#include <stdio.h> #include <stdlib.h> #include <unistd.h>//confstrint main (int argc, char **argv[]) { Char *pathbuf, *gun_libpthread_version_buf, *gun_libc_version_buf;size_t n;n = Confstr (_cs_path,null, (size_t) 0); Pathbuf = malloc (n), if (pathbuf = = NULL) abort (), Confstr (_cs_path, Pathbuf, N);p rintf ("_cs_path, A value for the PATH varia Ble:%s\n ", pathbuf); free (pathbuf);p athbuf = Null;n = Confstr (_cs_gnu_libpthread_version,null, (size_t) 0); if (n > 0) { Gun_libpthread_version_buf = malloc (n);} if (gun_libpthread_version_buf = = NULL) abort (); Confstr (_cs_gnu_libpthread_version, GUN_LIBPTHREAD_VERSION_BUF, N); printf ("_cs_gnu_libpthread_version, the POSIX implementation supplied by this C library:%s\n", Gun_libpthread_version_ BUF); free (gun_libpthread_version_buf); gun_libpthread_version_buf = Null;n = Confstr (_cs_gnu_libc_version,null, ( size_t) 0); if (n > 0) {gun_libc_version_buf = malloc (n);} if (gun_libc_version_buf = = NULL) abort (); Confstr (_cs_gnu_libc_version, Gun_libc_versiON_BUF, N);p rintf ("_cs_gnu_libc_version, the GNU C library VERSION on this system:%s\n", gun_libc_version_buf); Free (gun_ LIBC_VERSION_BUF); gun_libc_version_buf = Null;return 0;}

the output results are as follows:

_cs_path, A value for the PATH variable:/bin:/usr/bin_cs_gnu_libpthread_version, the POSIX implementation supplied by this C LIBRARY:NPTL 2.12_cs_gnu_libc_version, the GNU C library VERSION on this system:glibc 2.12

Linux Confstr and uname function _ get C library and kernel information