Linux下获取C标准库信息的函数 confstr
man 3 confstr
NAME
confstr - get configuration dependent string variables
SYNOPSIS
#include <unistd.h>
size_t confstr(int name, char *buf, size_t len);
函数根据name的值来获取相关信息，name目前支持的值有
1 _CS_GNU_LIBC_VERSION 表示查询GNU C库版本 只在GNU C库的2.3.2开始支持
_CS_GNU_LIBC_VERSION (GNU C library only; since glibc 2.3.2)
A string which identifies the GNU C library version on this system (e.g, "glibc 2.3.4").
2 CS_GNU_LIBPTHREAD_VERSION 查询posix标准的实现方
_CS_GNU_LIBPTHREAD_VERSION (GNU C library only; since glibc 2.3.2)
A string which identifies the POSIX implementation supplied by this C library (e.g, "NPTL 2.3.4" or "linuxthreads-0.10").
3 _CS_PATH PATH环境变量的值
_CS_PATH
A value for the PATH variable which indicates where all the POSIX.2 standard utilities can be found.
