Detect if presence of a character in a string with Lua - linux

I can have two types of string: nxs_flo_dev.nexus orfpdesk.
I want to test if there is a . in the string.
If there is a . I divide the string otherwise I do not do anything.
if(ngx.var.host.contains('.') then
content_by_lua 'ngx.say(ngx.var.host:match("(.-)%."))';
end
Is there a function to do that? Because .contains() doesn't work.


Use match again. Remember to escape the dot with %.:
if ngx.var.host:match('%.') then
If you want to do this inside content_by_lua do
content_by_lua 'if ngx.var.host:match('%.') then ngx.say(ngx.var.host:match("(.-)%.")) end';
Given your edit, this is the simplest solution:
content_by_lua 'ngx.say(ngx.var.host:match("(.-)%.") or ngx.var.host)';

Related

How to get a substring of this string Python3

string:
ecsdcsdcsdfvdfv":"https://scdsscdcsdent-mxp1-1.cdninstdscsdcagdssdcsdam.com/v/t51.283485-19/s320x320/79000872_1455436197941341_7513464347075543040_n.pnk?_nc_ht=scontent-mxp1-1.cdninadcdcdm.codcsdcm&_nc_ohc=0fehqjedb48AX8r72Hi&oh=eb1f6a78a2dcd67e443aa7f74eee91b4&oe=5E7F0A0C","vsvdfvsfvcfvfdcvfd
substring that i want to get:
https://scdsscdcsdent-mxp1-1.cdninstdscsdcagdssdcsdam.com/v/t51.283485-19/s320x320/79000872_1455436197941341_7513464347075543040_n.pnk?_nc_ht=scontent-mxp1-1.cdninadcdcdm.codcsdcm&_nc_ohc=0fehqjedb48AX8r72Hi&oh=eb1f6a78a2dcd67e443aa7f74eee91b4&oe=5E7F0A0C
i tried this but doesn't work
print (log.split("ecsdcsdcsdfvdfv",1)[1])

You can try this
log.split('":"')[1].split('","')[0]
But this is not the best way to do what you are trying to achieve. Better parse it and get what you want.

This yield the expected result.
The way you used .split() was wrong, you did not include the " character.
string = 'ecsdcsdcsdfvdfv":"https://scdsscdcsdent-mxp1-1.cdninstdscsdcagdssdcsdam.com/v/t51.283485-19/s320x320/79000872_1455436197941341_7513464347075543040_n.pnk?_nc_ht=scontent-mxp1-1.cdninadcdcdm.codcsdcm&_nc_ohc=0fehqjedb48AX8r72Hi&oh=eb1f6a78a2dcd67e443aa7f74eee91b4&oe=5E7F0A0C","vsvdfvsfvcfvfdcvfd'
substring = string.split('ecsdcsdcsdfvdfv":"')[1].split('","vsvdfvsfvcfvfdcvfd')[0]

If you want to get the string between the ":" and ",", then you can use regular expression to do it.
re.match('(.*\":\")([^\",\"]*)(\",\".*)', log).group(2)
Given your input
'ecsdcsdcsdfvdfv":"https://scdsscdcsdent-mxp1-1.cdninstdscsdcagdssdcsdam.com/v/t51.283485-19/s320x320/79000872_1455436197941341_7513464347075543040_n.pnk?_nc_ht=scontent-mxp1-1.cdninadcdcdm.codcsdcm&_nc_ohc=0fehqjedb48AX8r72Hi&oh=eb1f6a78a2dcd67e443aa7f74eee91b4&oe=5E7F0A0C","vsvdfvsfvcfvfdcvfd'
you will get
'https://scdsscdcsdent-mxp1-1.cdninstdscsdcagdssdcsdam.com/v/t51.283485-19/s320x320/79000872_1455436197941341_7513464347075543040_n.pnk?_nc_ht=scontent-mxp1-1.cdninadcdcdm.codcsdcm&_nc_ohc=0fehqjedb48AX8r72Hi&oh=eb1f6a78a2dcd67e443aa7f74eee91b4&oe=5E7F0A0C'
And if you input something like
'ecsdcsdcs":"dfvdfv":"https://s...F0A0C","vsvdfvsfvcfvfdc","vfd'
you will get
'https://s...F0A0C'
Dont forget to import re.

Is stringA in StringB in MATLAB

Is there a way to check if a string exists within another string in MATLAB. In python this is done easily with a in b. I do not want indexes or anything like that. I just want to check if its true or not. The answers that I find is "strcmp" or "strfind" and also regexp. regexp returns indexes. strcmp(a, b) does not seem to work. I have a string a = 'ac' and another string b = 'bc_gh_ac'. And want to check if a in b.
Best regards

The answer is indeed strfind. You have to be careful with the order of the parameters which at first seems unusual - the pattern is the second argument, not the first. The following code demonstrates:
a='ac';
b='bc_gh_ac';
strfind(b,a)
If you simply want to test whether the string is present or not then use the isempty function:
if ~isempty(strfind(b,a))
disp('String is present');
end

Display the specific part of the string in PostgreSQL 9.3

I have a string to modify as per the requirements.
For example:
The given string is:
str1 varchar = '123,456,789';
I want to show the string as:
'456,789'
Note: The first part (delimited) with comma, I want to remove from string and show the rest of string.
In SQL Server I used STUFF() function.
SELECT STUFF('123,456,789',1,4,'');
Result:
456,789
Question: Is there any string function in PostgreSQL 9.3 version to do the same job?

you can use regular expressions:
select substring('123,456,789' from ',(.*)$');
The comma matches the first comma found in the string. The part inside the brackets (.*) is returned from the function. The symbol $ means the end of the string.
A alternative solution without regular expressions:
select str, substring(str from position(',' in str)+1 for length(str)) from
(select '123,456,789'::text as str) as foo;

You could first turn the string to array and return second and third cell:
select array_to_string((regexp_split_to_array('123,456,789', ','))[2:3], ',')
Or you could use substring-function with regular expressions (pattern matching):
SELECT substring('123,456,789' from '[0-9]+,([0-9]+,[0-9]+)')
[0-9]+ means one or more digits
parentheses tell to return that part from the string
Both solutions work on your specific string.

Your The SQL Server example indicates you just want to remove the first 4 characters, which makes the rest of your question seem misleading because it completely ignores what's in the string. Only the positions matters.
Be that as it may, the simple and cheap way to cut off leading characters is with right():
SELECT right('123,456,789', -4);
SQL Fiddle.

Reading from a string using sscanf in Matlab

I'm trying to read a string in a specific format
RealSociedad
this is one example of string and what I want to extract is the name of the team.
I've tried something like this,
houseteam = sscanf(str, '%s');
but it does not work, why?

You can use regexprep like you did in your post above to do this for you. Even though your post says to use sscanf and from the comments in your post, you'd like to see this done using regexprep. You would have to do this using two nested regexprep calls, and you can retrieve the team name (i.e. RealSociedad) like so, given that str is in the format that you have provided:
str = 'RealSociedad';
houseteam = regexprep(regexprep(str, '^<a(.*)">', ''), '</a>$', '')
This looks very intimidating, but let's break this up. First, look at this statement:
regexprep(str, '^<a(.*)">', '')
How regexprep works is you specify the string you want to analyze, the pattern you are searching for, then what you want to replace this pattern with. The pattern we are looking for is:
^<a(.*)">
This says you are looking for patterns where the beginning of the string starts with a a<. After this, the (.*)"> is performing a greedy evaluation. This is saying that we want to find the longest sequence of characters until we reach the characters of ">. As such, what the regular expression will match is the following string:
<ahref="/teams/spain/real-sociedad-de-futbol/2028/">
We then replace this with a blank string. As such, the output of the first regexprep call will be this:
RealSociedad</a>
We want to get rid of the </a> string, and so we would make another regexprep call where we look for the </a> at the end of the string, then replace this with the blank string yet again. The pattern you are looking for is thus:
</a>$
The dollar sign ($) symbolizes that this pattern should appear at the end of the string. If we find such a pattern, we will replace it with the blank string. Therefore, what we get in the end is:
RealSociedad

Found a solution. So, %s stops when it finds a space.
str = regexprep(str, '<', ' <');
str = regexprep(str, '>', '> ');
houseteam = sscanf(str, '%*s %s %*s');
This will create a space between my desired string.

Lua: Search a specific string

Hi all tried all the string pattrens and library arguments but still stuck.
i want to get the name of the director from the following string i have tried the string.matcH but it matches the from the first character it finD from the string
the string is...
fixstrdirector = {id:39254,cast:[{id:15250,name:Hope Davis,character:Aunt Debra,order:5,cast_id:10,profile_path:/aIHF11Ss8P0A8JUfiWf8OHPVhOs.jpg},{id:53650,name:Anthony Mackie,character:Finn,order:3,cast_id:11,profile_path:/5VGGJ0Co8SC94iiedWb2o3C36T.jpg},{id:19034,name:Evangeline Lilly,character:Bailey Tallet,order:2,cast_id:12,profile_path:/oAOpJKgKEdW49jXrjvUcPcEQJb3.jpg},{id:6968,name:Hugh Jackman,character:Charlie Kenton,order:0,cast_id:13,profile_path:/wnl7esRbP3paALKn4bCr0k8qaFu.jpg},{id:79072,name:Kevin Durand,character:Ricky,order:4,cast_id:14,profile_path:/c95tTUjx5T0D0ROqTcINojpH6nB.jpg},{id:234479,name:Dakota Goyo,character:Max Kenton,order:1,cast_id:15,profile_path:/7PU6n4fhDuFwuwcYVyRNVEZE7ct.jpg},{id:8986,name:James Rebhorn,character:Marvin,order:6,cast_id:16,profile_path:/ezETMv0YM0Rg6YhKpu4vHuIY37D.jpg},{id:930729,name:Marco Ruggeri,character:Cliff,order:7,cast_id:17,profile_path:/1Ox63ukTd2yfOf1LVJOMXwmeQjO.jpg},{id:19860,name:Karl Yune,character:Tak Mashido,order:8,cast_id:18,profile_path:/qK315vPObCNdywdRN66971FtFez.jpg},{id:111206,name:Olga Fonda,character:Farra Lemkova,order:9,cast_id:19,profile_path:/j1qabOHf3Pf82f1lFpUmdF5XvSp.jpg},{id:53176,name:John Gatins,character:Kingpin,order:10,cast_id:41,profile_path:/A2MqnSKVzOuBf8MVfNyve2h2LxJ.jpg},{id:1126350,name:Sophie Levy,character:Big Sister,order:11,cast_id:42,profile_path:null},{id:1126351,name:Tess Levy,character:Little Sister,order:12,cast_id:43,profile_path:null},{id:1126352,name:Charlie Levy,character:Littlest Sister,order:13,cast_id:44,profile_path:null},{id:187983,name:Gregory Sims,character:Bill Panner,order:14,cast_id:45,profile_path:null}],crew:[{id:58726,name:Leslie Bohem,department:Writing,job:Screenplay,profile_path:null},{id:53176,name:John Gatins,department:Writing,job:Screenplay,profile_path:/A2MqnSKVzOuBf8MVfNyve2h2LxJ.jpg},{id:17825,name:Shawn Levy,department:Directing,job:Director,profile_path:/7f2f8EXdlWsPYN0HPGcIlG21xU.jpg},{id:12415,name:Richard Matheson,department:Writing,job:Story,profile_path:null},{id:57113,name:Dan Gilroy,department:Writing,job:Story,profile_path:null},{id:25210,name:Jeremy Leven,department:Writing,job:Story,profile_path:null},{id:17825,name:Shawn Levy,department:Production,job:Producer,profile_path:/7f2f8EXdlWsPYN0HPGcIlG21xU.jpg},{id:34970,name:Susan Montford,department:Production,job:Producer,profile_path:/1XJt51Y9ciPhkHrAYE0j6Jsmgji.jpg},{id:3183,name:Don Murphy,department:Production,job:Producer,profile_path:null},{id:34967,name:Rick Benattar,department:Production,job:Producer,profile_path:null},{id:1126348,name:Eric Hedayat,department:Production,job:Producer,profile_path:null},{id:186721,name:Ron Ames,department:Production,job:Producer,profile_path:null},{id:10956,name:Josh McLaglen,department:Production,job:Executive Producer,profile_path:null},{id:57634,name:Mary McLaglen,department:Production,job:Executive Producer,profile_path:null},{id:23779,name:Jack Rapke,department:Production,job:Executive Producer,profile_path:null},{id:488,name:Steven Spielberg,department:Production,job:Executive Producer,profile_path:/cuIYdFbEe89PHpoiOS9tmo84ED2.jpg},{id:30,name:Steve Starkey,department:Production,job:Executive Producer,profile_path:null},{id:24,name:Robert Zemeckis,department:Production,job:Executive Producer,profile_path:/isCuZ9PWIOyXzdf3ihodXzjIumL.jpg},{id:531,name:Danny Elfman,department:Sound,job:Original Music Composer,profile_path:/pWacZpYPos8io22nEiim7d3wp2j.jpg},{id:18265,name:Mauro Fiore,department:Crew,job:Cinematography,profile_path:null},{id:54271,name:Dean Zimmerman,department:Editing,job:Editor,profile_path:null},{id:25365,name:Richard Hicks,department:Production,job:Casting,profile_path:null},{id:5490,name:David Rubin,department:Production,job:Casting,profile_path:null},{id:52088,name:Tom Meyer,department:Art,job:Production Design,profile_path:null}]}
i have tried string.match(fixstrdirector,"name:(.+),department:Directing")
but it gives me the from the first occurace it find the name to the end of thr string
output:
Hope Davis,character:Aunt Debra,order:5,cast_id:10,profile_path:/aIHF11Ss8P0A8JUfiWf8OHPVhOs.jpg},{id:53650,name:Anthony Mackie,character:Finn,order:3,cast_id:11,profile_path:/5VGGJ0Co8SC94iiedWb2o3C36T.jpg},{id:19034,name:Evangeline Lilly,character:Bailey Tallet,order:2,cast_id:12,profile_path:/oAOpJKgKEdW49jXrjvUcPcEQJb3.jpg},{id:6968,name:Hugh Jackman,character:Charlie Kenton,order:0,cast_id:13,profile_path:/wnl7esRbP3paALKn4bCr0k8qaFu.jpg},{id:79072,name:Kevin Durand,character:Ricky,order:4,cast_id:14,profile_path:/c95tTUjx5T0D0ROqTcINojpH6nB.jpg},{id:234479,name:Dakota Goyo,character:Max Kenton,order:1,cast_id:15,profile_path:/7PU6n4fhDuFwuwcYVyRNVEZE7ct.jpg},{id:8986,name:James Rebhorn,character:Marvin,order:6,cast_id:16,profile_path:/ezETMv0YM0Rg6YhKpu4vHuIY37D.jpg},{id:930729,name:Marco Ruggeri,character:Cliff,order:7,cast_id:17,profile_path:/1Ox63ukTd2yfOf1LVJOMXwmeQjO.jpg},{id:19860,name:Karl Yune,character:Tak Mashido,order:8,cast_id:18,profile_path:/qK315vPObCNdywdRN66971FtFez.jpg},{id:111206,name:Olga Fonda,character:Farra Lemkova,order:9,cast_id:19,profile_path:/j1qabOHf3Pf82f1lFpUmdF5XvSp.jpg},{id:53176,name:John Gatins,character:Kingpin,order:10,cast_id:41,profile_path:/A2MqnSKVzOuBf8MVfNyve2h2LxJ.jpg},{id:1126350,name:Sophie Levy,character:Big Sister,order:11,cast_id:42,profile_path:null},{id:1126351,name:Tess Levy,character:Little Sister,order:12,cast_id:43,profile_path:null},{id:1126352,name:Charlie Levy,character:Littlest Sister,order:13,cast_id:44,profile_path:null},{id:187983,name:Gregory Sims,character:Bill Panner,order:14,cast_id:45,profile_path:null}],crew:[{id:58726,name:Leslie Bohem,department:Writing,job:Screenplay,profile_path:null},{id:53176,name:John Gatins,department:Writing,job:Screenplay,profile_path:/A2MqnSKVzOuBf8MVfNyve2h2LxJ.jpg},{id:17825,name:Shawn Levy

You're searching from the first occurrence of "name:" until the "department:Directing" with everything in between.
Instead, you need to restrict what can be between the two strings. Here for example I'm saying that the characters that make up the name can only be alphanumeric or a space:
string.match(fixstrdirector,"name:([%w ]+),department:Directing")
Alternatively, given that there's a comma separating the parameters, a better approach would be to search for "name:" followed by any characters other than a comma, followed by "department:Directing":
string.match(fixstrdirector,"name:([^,]+),department:Directing")
Of course that wouldn't work if the name had a comma it in!

Lua patterns provides - modifier for tasks as you have above. As stated on PiL - Section 20.2:
The + modifier matches one or more characters of the original class.
It will always get the longest sequence that matches the pattern.
Like *, the modifier - also matches zero or more occurrences of
characters of the original class. However, instead of matching the
longest sequence, it matches the shortest one.
Next, when you are using . to match, it'll find any and all characters satisfying the pattern. Therefore, you'll get the result from first occurence of name until the ,department:Directing is found. Since you know that it is a JSON data, you can try to match for [^,]; that is, non-comma characters.
So, for your case try:
local tAllNames = {}
for sName in fixstrdirector:gmatch( "name:([^,]-),department:Directing" ) do
tAllNames[ #tAllNames + 1 ] = sName
end
and all your required names will be stored in the table tAllNames. An example of the above can be seen at codepad.

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