32bit or 64bit

How to know your OS is 32bit or 64bit

判断操作系统是 32bit 的还是 64bit的。

uname –a
# Output: Linux pvxeon015 2.6.9-78.ELsmp #1 SMP Wed Jul 9 15:46:26 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux

How to know your cpu is 32bit or 64bit

判断 CPU 是32bit的还是64bit的。

grep flags /proc/cpuinfo
## lm = Long mode - 64 bit CPU
## 

Note: 64bit cpu can run a 32bit OS (64bit的cpu是可以安装32bit的操作系统的)

How to know your executable is 32bit or 64bit

判断一个二进制可执行文件是32bit的还是64bit的。

file /depot/coreutils-5.2.1/bin/ls
# Output: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.2.5 …

How to compile 32bit executable on 64bit macine

在64bit的环境下编译32bit的程序。

g++ -m32 ….

We know amd64, is there something like Intel-64?

AMD64 和 Intel-64有什么分别呢？

Yes. There are Intel-64 implementation. http://en.wikipedia.org/wiki/X86-64

But AMD implement the 64bit architecture first, and Intel-64 is comparable with AMD-64, so people use AMD64 for x86-64.