erlang学习笔记 跨系统erlang查询脚本

1.利用 os:cmd 执行命令进行查询

2.利用 os:type 检查os版本, 对于不同操作系统的不同做不不同的处理

3 os:getpid, 获得自身的进程号

os 参考:http://www.erlang.org/doc/man/os.html

代码转自yufeng http://mryufeng.javaeye.com/blog/636809

-module(fd).

-export([start/0]).

get_total_fd_ulimit() ->

{MaxFds, _} = string:to_integer(os:cmd("ulimit -n")),

MaxFds.

get_total_fd() -> get_total_fd(os:type()).

get_total_fd({unix, Os})

when Os =:= linux orelse

Os =:= darwin orelse

Os =:= freebsd orelse Os =:= sunos ->

get_total_fd_ulimit();

get_total_fd(_) -> unknown.

get_used_fd_lsof() ->

Lsof = os:cmd("lsof -d \"0-9999999\" -lna -p " ++

os:getpid()),

string:words(Lsof, $\n).

get_used_fd() -> get_used_fd(os:type()).

get_used_fd({unix, Os})

when Os =:= linux orelse

Os =:= darwin orelse Os =:= freebsd ->

get_used_fd_lsof();

get_used_fd(_) -> unknown.

start()->

io:format("total fd: ~p~n"

"used fd: ~p~n", [get_total_fd(), get_used_fd()]),

halt(0).