How to escape a portion of a string in regular expressions

Hello,

i want to dynamically create a regular expression from an input string. However i only want a small subset of expressions to be treated as such. Most of the input shall be treated as literal (e.g. dots '.' shall actually be treated as dots and not wildcards)

Is there a way to escape a whole group/substring when defining a regexp, or is the only way to escape all special chars, except the ones i want to keep, manually. If i need to escape everything manually, is there a syntax/keyword which gets me all special chars in the string so i can escape all of them?

Example (dots shall be treated as literal dots):

>> r = myfun('a.b.c','a.b.')
r = 1

>> r_myfun('aXb.c','a.b.')
r = []

[Rik]

I think that would be the best solution: find all special characters and escape them. Be careful with how you implement that. A list of strreps would have side effects:

str='a.b';
str=strrep(str,'.','\.');
str=strrep(str,'\','\\');
str

str = 'a\\.b'

[Max Heimann]

Given how many operators are supported this list could get quite long. I was hoping there was a way to write something like regexp('a.b.c.','\escapeThisGroup(a.b.)') meaning i am looking for a literal match for 'a.b.'.

IIRC java does this with \Q and \E.

[Walter Roberson]

Perhaps the newer "pattern" facilities would help?

[Max Heimann]

Thats also great, but i need it to work in an earlier version than 2020.

Answer 1

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/regexptranslate.html

regexptranslate with the 'wildcard' option, perhaps?

[Max Heimann]

This is great, thank you. I think i can work with this and use the 'escape' option. Afterwards i can look for the escaped versions of the patterns i want to match and de-escape them.