ngx.re.match及ngx.re.find中options参数的困惑

jie123108 · 2016-11-10T16:21:49+00:00

Hello! 2016-11-09 1:44 GMT-08:00 Ivan King: > 现在有新的疑问，在什么情况&#...

ngx.re.match及ngx.re.find中options参数的困惑

jie123108

Hi,春哥，及各位：

在使用ngx.re.find时，关于以下两个参数，有点困惑：

m             multi-line mode (similar to Perl's /m modifier)
s             single-line mode (similar to Perl's /s modifier)

按我的理解，s是只能匹配到单行的，m是可以匹配到多行的，但是我实际测试，刚好相反：

local content = [[
#EXTM3U
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:5.000000,
84ad54899b6cd89046b5e8ac816b39eb-00001.ts
#EXTINF:5.000000,
84ad54899b6cd89046b5e8ac816b39eb-00002.ts
#EXTINF:5.000000,
]]

local ts_pattern = [[[^#\n].*\.ts]]
ngx.re.find(content, ts_pattern)
local from, to, err = ngx.re.find(content, ts_pattern, "jos")
if from then
ngx.say("jos matched: [[", string.sub(content, from, to), "]]")
end
local from, to, err = ngx.re.find(content, ts_pattern, "jom")
if from then
ngx.say("jom matched: [[", string.sub(content, from, to), "]]")
end

这段代码输出是这样的：

resty test.lua
jos matched: [[EXTM3U
#EXT-X-MEDIA-SEQUENCE:0
#EXTINF:5.000000,
84ad54899b6cd89046b5e8ac816b39eb-00001.ts
#EXTINF:5.000000,
84ad54899b6cd89046b5e8ac816b39eb-00002.ts]]
jom matched: [[84ad54899b6cd89046b5e8ac816b39eb-00001.ts]]

可以看到：s选项返回了多行，m选项返回了一行，请问这是什么原因导致的？还是我理解有误？

jie123108

附上nginx版本：

nginx -V
nginx version: openresty/1.11.2.1
built by gcc 4.4.7 20120313 (Red Hat 4.4.7-17) (GCC)
built with OpenSSL 1.0.1e-fips 11 Feb 2013
TLS SNI support enabled
configure arguments: --prefix=/usr/local/ngx_openresty/nginx --with-cc-opt=-O2 --add-module=../ngx_devel_kit-0.3.0 --add-module=../echo-nginx-module-0.60 --add-module=../xss-nginx-module-0.05 --add-module=../ngx_coolkit-0.2rc3 --add-module=../set-misc-nginx-module-0.31 --add-module=../form-input-nginx-module-0.12 --add-module=../encrypted-session-nginx-module-0.06 --add-module=../srcache-nginx-module-0.31 --add-module=../ngx_lua-0.10.6 --add-module=../ngx_lua_upstream-0.06 --add-module=../headers-more-nginx-module-0.31 --add-module=../array-var-nginx-module-0.05 --add-module=../memc-nginx-module-0.17 --add-module=../redis2-nginx-module-0.13 --add-module=../redis-nginx-module-0.3.7 --add-module=../rds-json-nginx-module-0.14 --add-module=../rds-csv-nginx-module-0.07 --with-ld-opt=-Wl,-rpath,/usr/local/ngx_openresty/luajit/lib --with-http_sub_module --with-http_gzip_static_module --with-http_stub_status_module --with-poll_module --with-pcre=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../pcre-8.37 --with-zlib=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../zlib-1.2.8 --add-module=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../ngx_request_stats --add-module=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../ngx_geo_mod --with-http_mp4_module --with-http_flv_module --with-stream --with-http_ssl_module

moonbingbing

你对于这两个 Modifiers 的理解是不对的，你看下官方文档，写的非常清楚：

m
Treat the string as multiple lines. That is, change "^" and "$" from matching the start of the string's first line and the end of its last line to matching the start and end of each line within the string.
s
Treat the string as single line. That is, change "." to match any character whatsoever, even a newline, which normally it would not match.

2016-11-10 16:41 GMT+08:00 xiaojie liu <jie1...@gmail.com>:

附上nginx版本：
nginx -V
nginx version: openresty/1.11.2.1
built by gcc 4.4.7 20120313 (Red Hat 4.4.7-17) (GCC)
built with OpenSSL 1.0.1e-fips 11 Feb 2013
TLS SNI support enabled
configure arguments: --prefix=/usr/local/ngx_openresty/nginx --with-cc-opt=-O2 --add-module=../ngx_devel_kit-0.3.0 --add-module=../echo-nginx-module-0.60 --add-module=../xss-nginx-module-0.05 --add-module=../ngx_coolkit-0.2rc3 --add-module=../set-misc-nginx-module-0.31 --add-module=../form-input-nginx-module-0.12 --add-module=../encrypted-session-nginx-module-0.06 --add-module=../srcache-nginx-module-0.31 --add-module=../ngx_lua-0.10.6 --add-module=../ngx_lua_upstream-0.06 --add-module=../headers-more-nginx-module-0.31 --add-module=../array-var-nginx-module-0.05 --add-module=../memc-nginx-module-0.17 --add-module=../redis2-nginx-module-0.13 --add-module=../redis-nginx-module-0.3.7 --add-module=../rds-json-nginx-module-0.14 --add-module=../rds-csv-nginx-module-0.07 --with-ld-opt=-Wl,-rpath,/usr/local/ngx_openresty/luajit/lib --with-http_sub_module --with-http_gzip_static_module --with-http_stub_status_module --with-poll_module --with-pcre=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../pcre-8.37 --with-zlib=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../zlib-1.2.8 --add-module=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../ngx_request_stats --add-module=/usr/local/src/ngx_openresty/openresty-1.11.2.1/../ngx_geo_mod --with-http_mp4_module --with-http_flv_module --with-stream --with-http_ssl_module

--

jie123108

我只看了https://github.com/openresty/lua-nginx-module 上面的文档说明，没看到这个说明。敢问一下，你发的这个说明，来自哪个文档？我去看一下。

2016-11-10 17:04 GMT+08:00 Ming <moonb...@gmail.com>:

你对于这两个 Modifiers 的理解是不对的，你看下官方文档，写的非常清楚：
m
Treat the string as multiple lines. That is, change "^" and "$" from matching the start of the string's first line and the end of its last line to matching the start and end of each line within the string.
s
Treat the string as single line. That is, change "." to match any character whatsoever, even a newline, which normally it would not match.

moonbingbing

http://perldoc.perl.org/perlre.html#Modifiers

来自 perl 的文档

在 2016年11月10日下午5:12，xiaojie liu <jie1...@gmail.com>写道：

我只看了https://github.com/openresty/lua-nginx-module 上面的文档说明，没看到这个说明。敢问一下，你发的这个说明，来自哪个文档？我去看一下。

2016-11-10 17:04 GMT+08:00 Ming <moonb...@gmail.com>:
你对于这两个 Modifiers 的理解是不对的，你看下官方文档，写的非常清楚：
m
Treat the string as multiple lines. That is, change "^" and "$" from matching the start of the string's first line and the end of its last line to matching the start and end of each line within the string.
s
Treat the string as single line. That is, change "." to match any character whatsoever, even a newline, which normally it would not match.

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