erlang内置函数

123表示数字'123'表示原子"123"表示列表

whereis(RegName)->pid()|port()|undefinedReturnsthepidorportidentifierwiththeregisterednameRegName

unregister(RegName)->true

RemovestheregisterednameRegName,associatedwithapidoraportidentifier.

time()->Time{Hour,Minute,Second}.

now()->Timestamp{MegaSecs,Secs,MicroSecs}

localtime()->DateTime{{Year,Month,Day},{Hour,Minute,Second}}

throw(Any)->no_return()

catchthrow({hello,there}).//{hello,there}

Failure:nocatchifnotevaluatedwithinacatch.

Bin=term_to_binary(Tuple).//<<131,104,3,100,0,1,97,100,0,1,98,100,0,1,99>>

binary_to_term(Bin).//{a,b,c}

statistics(wall_clock).//统计运行时间

erlang:start_timer(Time,Dest,Msg)->TimerRef

Startsatimerwhichwillsendthemessage{timeout,..}toDestafterTimemilliseconds.

erlang:send_after(Time,Dest,Msg)->TimerRef

StartsatimerwhichwillsendthemessageMsgtoDestafterTimemilliseconds.

split_binary(Bin,Pos)->{binary(),binary()}

list_to_binary("0123456789").

{B1,B2}=split_binary(B,3).->B1=<<"012">>.

插入新元素到元组中

insert_element(2,{one,two,three},new).->{one,new,two,three}

append_element({one,two},three).->{one,two,three}

element(1,{a,b,[c,d]})->a获取元组的第1个元素

tuple_size({a,b,{c,d}}).->3

is_tuple({})->trueis_tuple(a)->false

is_atom(Term)

is_binary(Term)

is_bitstring(Term)

is_function(Term)->boolean()

is_list(Term)->boolean()

is_integer(Term)->boolean()等is_xxx函数

float(55).->55.0

round(5.5)->6

tuple_to_list({a,b,[c,d]}).->[a,b,[c,d]]

list_to_tuple([a,b,{d,e}]).->{a,b,{d,e}}

list_to_integer("123").->123

list_to_integer("3FF",16).->1023

integer_to_list(13).->"13"注意不能用13.0badargument异常

integer_to_binary(77).-><<"77">>

binary_to_integer(<<"123">>).->123

binary_to_integer(<<"3FF">>,16).->1023

list_to_float("1.34").->1.34注意使用"1"作为参数badargment异常

float_to_list(1.34)->"1.34000000000000007994e+00"

float_to_binary(7.12,[{decimals,4}]).-><<"7.1200">>

float_to_binary(7.12,[{decimals,4},compact]).-><<"7.12">>

atom_to_list(abc).->"abc"

list_to_atom([1,2,3])->'\001\002\003'但[a,b,c]则badargument异常

list_to_atom([$1,$2,$3])->'123'

list_to_binary([1,2,3])-><<1,2,3>>但[a,b,c]则badargument异常

list_to_binary([$1,$2,$3])-><<"123">>.<<1,2,3>>不等同于<<"123">>

list_to_bitstring([1,2,3])-><<1,2,3>>但[a,b,c]则badargument异常

list_to_bitstring([$1,$2,$3])-><<"123">>.

正确的用法list_to_atom([$a,$b,$c]).

binary_to_term(Binary)->term()

hd([a,b,c])->a

tl([a,b,c]).->[b,c].返回tail部分，空列表badargument异常

length([a,c,b])->3

spawn(Fun)->pid()

spawn(Node,Fun)->pid()

spawn(Module,Function,Args)->pid()

spawn(Node,Module,Function,Args)->pid()

spawn_link(Module,Function,Args)->pid()

spawn_link(Node,Module,Function,Args)->pid()

exit(Reason)->no_return()

StopstheexecutionofthecallingprocesswiththeexitreasonReason

catchexit(foobar).->{'EXIT',foobar}

exit(Pid,Reason)->true

SendsanexitsignalwithexitreasonReasontotheprocessorportidentifiedbyPid.

link(PidOrPort)->true

Createsalinkbetweenthecallingprocessandanotherprocess(orport)

unlink(Id)->true

Removesthelink,ifthereisone,betweenthecallingprocessandtheprocessorportreferredtobyId.

register(RegName,PidOrPort)->true

registered()->[RegName]

processes()->[pid()]Returnsalistofprocessidentifierscorrespondingtoalltheprocessescurrentlyexistingonthelocalnode.

purge_module(Module)->true

RemovesoldcodeforModule.BeforethisBIFisused,erlang:check_process_code/2shouldbecalledtocheckthatnoprocessesareexecutingoldcodeinthemodule.

erlang:loaded()->[Module]

ReturnsalistofallloadedErlangmodules(currentand/oroldcode)

erlang:send(Dest,Msg)->Msg等同于Dest!Msg

self()->pid()

nodes()Returnsalistofallvisiblenodesinthesystem,excludingthelocalnode

node()->NodeReturnsthenameofthelocalnode.

进程字典相关函数：

put(name,sky).

put(sex,1).

get()->[{Key,Val}]

get(name)->sky

erase(name).

erase().