how to open an external text file, identify two strings and save the lines of the text file where the two strings appear
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Hi,
I would like to open an external text file, identify two strings, for example "Pattern1" and "Pattern2" and save in two variables, line1 and line2, the number of the line of the text file where "Pattern1" and "Pattern2". I am attaching the text file. In this example line1=12 and line2=24
I thank you in advance,
Best regards,
Hugo
1 Commento
Risposta accettata
Mathieu NOE
il 12 Mar 2021
hello Hugo
see below
Filename = 'sample_text.txt';
[Pattern1_line, Pattern2_line] = extract_data(Filename);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function [Pattern1_line, Pattern2_line] = extract_data(Filename)
fid = fopen(Filename);
tline = fgetl(fid);
% initialization
k = 0;
p = 0;
q = 0;
Pattern1_line = 0;
Pattern2_line = 0;
while ischar(tline)
k = k+1; % loop over line index
% retrieve line Date/Time
if contains(lower(tline),'pattern1') % lower make matlab not case sensitive
Pattern1_line = k;
end
% retrieve line Date/Time
if contains(lower(tline),'pattern2') % lower make matlab not case sensitive
Pattern2_line = k;
end
tline = fgetl(fid);
end
fclose(fid);
end
1 Commento
Jan
il 29 Giu 2021
Note: contains has an option to ignore the case. This is more efficient than lower() of the input.
Più risposte (2)
Jan
il 29 Giu 2021
S = fileread('sample_text.txt');
C = strsplit(S, '\n');
Pattern1_line = find(contains(C, 'Pattern1', 'IgnoreCase', true));
Pattern2_line = find(contains(C, 'Pattern2', 'IgnoreCase', true));
0 Commenti
Hugo
il 12 Mar 2021
3 Commenti
Mathieu NOE
il 16 Mar 2021
hello
you should get the two variables in your workspace
that's what the line :
[Pattern1_line, Pattern2_line] = extract_data(Filename);
does.
proof :
I got in my workspace :
Pattern1_line = 12
Pattern2_line = 24
Now if you want to save it in a output file, I didn't code it but I suppose you know how to do it
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