Replace string in text file
64 views (last 30 days)
Show older comments
Kian
on 12 Aug 2020
Answered: kuchina mani chandra
on 3 Apr 2023
I have a txt file in which there are a bunch of lines. The first two lines are shown below:
10125731872 50 3731 -9999 307 166 -9999 827 4090 -9999 587 332 5 -9999
10125731873 50 117 322 9 -9999 187 300 1273 280 103 -9999 39 -9999
I need to add an "M" after all -9999 values. In a text editor this would be simply done by using the replace tool while looking for all "-9999 " and replacing them with "-9999M". Simple! But I have a hard time doing the same thing in Matlab.
Any idea how I can do this simple task?
Thanks.
0 Comments
Accepted Answer
Walter Roberson
on 12 Aug 2020
filename = 'a_txt_file.txt';
new_filename = ['new_' filename];
S = fileread(filename);
S = regexprep(S, '-9999\>', '$&M');
fid = fopen(new_filename, 'w');
fwrite(fid, S);
fclose(fid);
It is recommended that new_filename be different than filename: otherwise if something goes wrong in the writing process, you could lose your only copy of the input.
5 Comments
Walter Roberson
on 12 Aug 2020
Edited: Walter Roberson
on 12 Aug 2020
regexprep(S, '-9999( |$)', '-9999M', 'lineanchors' )
More Answers (1)
kuchina mani chandra
on 3 Apr 2023
Function replaceStringIntxtFile(filepath,stringToReplace,ReplaceWith) Filedata = readlines(filepath); replacedFiledata =replace(Filedata,stringToReplace,ReplaceWith); F=fopen(filepath,'w'); fprintf(f,'%s\n'replacedFiledata); fclose(f) end
0 Comments
See Also
Categories
Find more on Characters and Strings in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!