how to find index of each occurrence of my pattern in a file

Hi,

I have text file (contents are shown belew)

Hi Helo

How are you mekala

what are you doing

where are you going mekala

I want to get the row index if row contains "mekala

I use below code:

fid=fopen("test.txt")

data=fgetl(fid)

idx=strfind(data,'mekala').

idx is showing empty.

[Ruger28]

fgetl gets a single line. You need to read your entire file in and then try something like you have above.

Answer 1

[Meg Noah]

This solution will find the lines that contain the whole phrase. The example illustrates how to consider or not consider the case of the letters. It alludes to whether or not a word is plural. Operates on the attached text files. If the phrase is split between two or more lines a different solution would be needed. Is this sufficient for your needs?

%% read the text file
%% find same word phrase in a single line 
%  a phrase with line-break will not be displayed
disp('Example: Case Sensitive');
filename = 'Buffaloes.txt';
searchPhrase = 'lying low';

strContents = fileread(filename);
fileAsCellArray = regexp(strContents, '\r\n|\r|\n', 'split');
fileAsCellArray = fileAsCellArray';
% find(~cellfun('isempty',contains(fileAsCellArray,searchPhrase)))
idxLineWithSearchPhrase = find(contains(fileAsCellArray,searchPhrase));
if (~isempty(idxLineWithSearchPhrase))
    fprintf(1,'In %s, found %d lines with phrase: %s\n',filename,length(idxLineWithSearchPhrase),searchPhrase);
    for iline = 1:length(idxLineWithSearchPhrase)
        fprintf(1,'Line %d: %s\n',idxLineWithSearchPhrase(iline), ...
            fileAsCellArray{idxLineWithSearchPhrase(iline)});
    end
else
    fprintf(1,'In %s, found no lines with phrase: %s\n',filename,searchPhrase);
end

%% make the above example case insensitive
disp(' ');
disp('Example: Case Insensitive');
filename = 'Buffaloes.txt';
searchPhrase = 'lying low';

strContents = lower(fileread(filename));
fileAsCellArray = regexp(strContents, '\r\n|\r|\n', 'split');
fileAsCellArray = fileAsCellArray';
% find(~cellfun('isempty',contains(fileAsCellArray,searchPhrase)))
idxLineWithSearchPhrase = find(contains(fileAsCellArray,searchPhrase));
if (~isempty(idxLineWithSearchPhrase))
    fprintf(1,'In %s, found %d lines with phrase: %s\n',filename,length(idxLineWithSearchPhrase),searchPhrase);
    for iline = 1:length(idxLineWithSearchPhrase)
        fprintf(1,'Line %d: %s\n',idxLineWithSearchPhrase(iline), ...
            fileAsCellArray{idxLineWithSearchPhrase(iline)});
    end
else
    fprintf(1,'In %s, found no lines with phrase: %s\n',filename,searchPhrase);
end

%% Just a word
disp(' ');
disp('Example: Case Insensitive - single word (may or may not be plural)');
filename = 'Daffodils.txt';

% single
searchPhrase = 'daffodil ';
strContents = lower(fileread(filename));
fileAsCellArray = regexp(strContents, '\r\n|\r|\n', 'split');
fileAsCellArray = fileAsCellArray';
% find(~cellfun('isempty',contains(fileAsCellArray,searchPhrase)))
idxLineWithSearchPhrase = find(contains(fileAsCellArray,searchPhrase));
if (~isempty(idxLineWithSearchPhrase))
    fprintf(1,'In %s, found %d lines with phrase: %s\n',filename,length(idxLineWithSearchPhrase),searchPhrase);
    for iline = 1:length(idxLineWithSearchPhrase)
        fprintf(1,'Line %d: %s\n',idxLineWithSearchPhrase(iline), ...
            fileAsCellArray{idxLineWithSearchPhrase(iline)});
    end
else
    fprintf(1,'In %s, found no lines with phrase: %s\n',filename,searchPhrase);
end

% plural
searchPhrase = 'daffodils';
strContents = lower(fileread(filename));
fileAsCellArray = regexp(strContents, '\r\n|\r|\n', 'split');
fileAsCellArray = fileAsCellArray';
% find(~cellfun('isempty',contains(fileAsCellArray,searchPhrase)))
idxLineWithSearchPhrase = find(contains(fileAsCellArray,searchPhrase));
if (~isempty(idxLineWithSearchPhrase))
    fprintf(1,'In %s, found %d lines with phrase: %s\n',filename,length(idxLineWithSearchPhrase),searchPhrase);
    for iline = 1:length(idxLineWithSearchPhrase)
        fprintf(1,'Line %d: %s\n',idxLineWithSearchPhrase(iline), ...
            fileAsCellArray{idxLineWithSearchPhrase(iline)});
    end
else
    fprintf(1,'In %s, found no lines with phrase: %s\n',filename,searchPhrase);
end