我尝试过的 cgi 脚本无法从我的 inets httpd 服务器检索 json 数据。
为了在 cgi 脚本中检索 json 数据，您需要能够读取请求的主体，其中将包含以下内容：
{"a": 1, "b": 2}
使用 perl cgi 脚本，我可以读取如下请求的正文：
my $cgi = CGI->new;
my $req_body = $cgi->param('POSTDATA');
我认为这是读取服务器管道到脚本标准输入的间接方式，因为在 python cgi 脚本中我必须编写：
req_body = sys.stdin.read()
当我从apache服务器请求 cgi 脚本时，我的 perl 和 python cgi 脚本可以成功地从 apache 获取 json 数据。但是当我从我的inets httpd服务器请求相同的 cgi 脚本时，我的 perl cgi 脚本对请求正文没有读取任何内容，并且我的 python cgi 脚本挂起然后服务器超时。我的 cgi 脚本能够"a=1&b=2"从服务器检索格式化为格式的数据inets httpd——在这种情况下，perl 和 python 中的 cgi 工具会自动为我解析数据，因此我无需尝试读取请求的正文，而是访问结构那个cgi创建的。
这是我的 httpd 服务器配置（server.conf）：
[
{modules, [
mod_alias,
mod_actions,
mod_esi,
mod_cgi,
mod_get,
mod_log
]},
{bind_address, "localhost"},
{port,0},
{server_name,"httpd_test"},
{server_root,"/Users/7stud/erlang_programs/inets_proj"},
{document_root,"./htdocs"},
{script_alias, {"/cgi-bin/", "/Users/7stud/erlang_programs/inets_proj/cgi-bin/"} },
{erl_script_alias, {"/erl", [mymod]} },
{erl_script_nocache, true},
{error_log, "./errors.log"},
{transfer_log, "./requests.log"}
].
我用这个程序（）启动我的 httpd 服务器s.erl：
-module(s).
-compile(export_all).
%Need to look up port with httpd:info(Server)
ensure_inets_start() ->
case inets:start() of
ok -> ok;
{error,{already_started,inets}} -> ok
end.
start() ->
ok = ensure_inets_start(),
{ok, Server} = inets:start(httpd,
[{proplist_file, "./server.conf"}]
),
Server.
stop(Server) ->
ok = inets:stop(httpd, Server).
我的 cgi 脚本 ( 1.py):
#!/usr/bin/env python3
import json
import cgi
import cgitb
cgitb.enable() #errors to browser
import sys
sys.stdout.write("Content-Type: text/html")
sys.stdout.write("\r\n\r\n")
#print("<div>hello</div>")
req_body = sys.stdin.read()
my_dict = json.loads(req_body)
if my_dict:
a = my_dict.get("a", "Not found")
b = my_dict.get("b", "Not found")
total = a + b
print("<div>Got json: {}</div>".format(my_dict) )
print("<div>a={}, b={}, total={}</div>".format(a, b, total))
else:
print("<div>Couldn't read json data.</div>")
我的 cgi 脚本 ( 1.pl):
#!/usr/bin/env perl
use strict;
use warnings;
use 5.020;
use autodie;
use Data::Dumper;
use CGI;
use CGI::Carp qw(fatalsToBrowser);
use JSON;
my $q = CGI->new;
print $q->header,
$q->start_html("Test Page"),
$q->h1("Results:"),
$q->div("json=$json"),
$q->end_html;
在终端窗口中启动服务器：
~/erlang_programs/inets_proj$ erl
Erlang/OTP 20 [erts-9.2] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:10] [hipe] [kernel-poll:false]
Eshell V9.2 (abort with ^G)
1> c(s).
s.erl:2: Warning: export_all flag enabled - all functions will be exported
{ok,s}
2> Server = s:start().
<0.86.0>
3> httpd:info(Server).
[{mime_types,[{"htm","text/html"},{"html","text/html"}]},
{server_name,"httpd_test"},
{erl_script_nocache,true},
{script_alias,{"/cgi-bin/",
"/Users/7stud/erlang_programs/inets_proj/cgi-bin/"}},
{bind_address,{127,0,0,1}},
{modules,[mod_alias,mod_actions,mod_esi,mod_cgi,mod_get,
mod_log]},
{server_root,"/Users/7stud/erlang_programs/inets_proj"},
{erl_script_alias,{"/erl",[mymod]}},
{port,51301},
{transfer_log,<0.93.0>},
{error_log,<0.92.0>},
{document_root,"./htdocs"}]
4>
卷曲请求：
$ curl -v \
> -H 'Content-Type: application/json' \
> --data '{"a": 1, "b": 2}' \
> http://localhost:51301/cgi-bin/1.py
* Trying ::1...
* TCP_NODELAY set
* Connection failed
* connect to ::1 port 51301 failed: Connection refused
* Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to localhost (127.0.0.1) port 51301 (#0)
> POST /cgi-bin/1.py HTTP/1.1
> Host: localhost:51301
> User-Agent: curl/7.58.0
> Accept: */*
> Content-Type: application/json
> Content-Length: 16
>
* upload completely sent off: 16 out of 16 bytes
===== hangs for about 5 seconds ====
< HTTP/1.1 504 Gateway Time-out
< Date: Thu, 08 Mar 2018 11:02:27 GMT
< Content-Type: text/html
< Server: inets/6.4.5
* no chunk, no close, no size. Assume close to signal end
<
* Closing connection 0
$
我的目录结构：
~/erlang_programs$ tree inets_proj/
inets_proj/
├── apache_cl.erl
├── cgi-bin
│ ├── 1.pl
│ └── 1.py
├── cl.beam
├── cl.erl
├── errors.log
├── htdocs
│ └── file1.txt
├── mylog.log
├── mymod.beam
├── mymod.erl
├── old_server.conf
├── old_server3.conf
├── old_server4.conf
├── requests.log
├── s.beam
├── s.erl
├── server.conf
└── urlencoded_post_cl.erl