Matlab: Find a string in a text file - matlab

Question

I've searched around, bud didn't find a proper solution. So I ask it again.
There many lines in the .txt file. Looks Like this:
PRINT CONTENTS OF SUPERELEMENT yg_bde
PRINT OPTION = 3
HEADER =
8 55 2 12 6
13 0 13 11 0
1 1 0 0 1
0 0 1 78 14014
0 1584 166 103 yg_b
de 1561 0
922 931 1105 1121 1144
1158 1323 1503 0 989
1047 110005225 0 0 3
0 0
419 0 0 0 0
0 0 0 0
HEADER SUMMARY:
NUMBER OF ROWS = 55
NUMBER OF MATRICES = 2
NUMBER OF EDGE PLOT LINES = 12
NUMBER OF DEGREES OF FREEDOM PER NODE = 6
NUMBER OF DEGREE OF FREEDOM INDICES = 13
NUMBER OF NODES = 11
NUMBER OF LOAD VECTORS = 1
NUMBER OF TRANSFORMATIONS = 0
BASE FILE NAME= yg_bde
I need to locate the NUMBER OF ROWS = 55 and get the row number.
I think what need to do is
1. find and locate the Number of ROWS
2. Turn this line into number, so I can get the 55 number
I tried strfind(file ,string), but it can't return the line number, just the index when the file is in one line.
So, How can I Locate the NUMBER OF ROWS?
UPDATE:
whos data
Name Size Bytes Class Attributes
data 1x1 3094 struct

Answer 1

Approach #1
importdata based approach -
%// Import text data as a cell array with each cell holding each row of text data
data = importdata(inputfile,'\n') %// Edit inputfile to the path of your text file
%// Find the row(s) that holds the string 'NUMBER OF ROWS'
row_idx = find(~cellfun('isempty',strfind(data,'NUMBER OF ROWS')))
%// Find the number(s) in that/those row(s)
num = arrayfun(#(x) regexp(data{x}, '\d+', 'match'),row_idx)
Output I got -
row_idx =
19
num =
'55'
Now, num is a cell array. If you would like to have a numeric array, wrap it with str2double -
num_array = str2double(num)
Note: This also works if you have multiple lines with the string 'NUMBER OF ROWS'.
Approach #2
Alternative fgetl based approach that works by reading the text file line-by-line -
fid = fopen(inputfile); %// Edit inputfile to the path of your text file
tline = fgetl(fid);
num = [];
while ischar(tline)
if ~isempty(strfind(tline,'NUMBER OF ROWS'))
num = [num regexp(tline, '\d+', 'match')]; %#ok<AGROW>
end
tline = fgetl(fid);
end
fclose(fid);
num_array = str2double(num)