Extract value until regexp case match

Hi,

I have this string. I was hoping to use regexp in order to extract the time and date embedded in this string. I was going to use regexp '.*?<=216', as prior to 216 is all the values I was hoping to extract. I was hoping that there would be an easy way to extract the date and time to a separate cell array. Thanks for any and all help.

"9/12/2022 7:38:51 PM

216 Indicator"

[Rik]

While this could work, is there a reason why you can't match the date itself directly?

[Dyel]

Is there a way using regexp to extract the datetime value, or something similar from a char array?

Answer 1

[Stephen23]

Does the data you want to match always occur at the start of the string?

A = "9/12/2022 7:38:51 PM 216 Indicator";
B = regexp(A,'^\S+\s+\S+\s[AP]M','match','once')

B = "9/12/2022 7:38:51 PM"

T = datetime(B,'inputFormat','d/M/u h:m:s aa')

T = datetime
   09-Dec-2022 19:38:51

[Dyel]

This did the trick. Thanks Stephen.

How I did it was to split it up using the SplitString fuction, and then convert the string with the date to datetime, in case anyone may find it useful.

 for j = 1:length(cf)
        loopname = cf(j).name;
        filetext = fileread(loopname);
        txtStr = convertCharsToStrings(filetext);
        indVal{i,j} = cell2mat(regexp(filetext, '(?<=Indicator[^0-9]*)[+-]?[0-9]*\.?[0-9]+', 'match'));
        splitStr = regexp(txtStr,'\n','split');
        dateStr = splitStr{1};
        date = datetime(dateStr);
        dateVal{i,j} = date;
        
    end