How do I find the number of character in a text file?
2 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
I have a text file 'inp.txt' containing one line like this:
'banerjee.raktim 123456789125'
I want to know the number of character present in this line, including the white space. And also want to know the position of the white space character.
The expected no of character is 28 and opsition of space is:
16
How to do this?
0 comentarios
Respuesta aceptada
Matt Fig
el 26 de En. de 2011
fid = fopen('inp.txt'); % see also fclose
A = char(fread(fid,inf)).';
A =
banerjee.raktim 123456789125
>> length(A)
ans =
28
>> strfind(A,' ')
ans =
16
3 comentarios
Jan
el 26 de En. de 2011
This "A = char(fread(fid,inf)).';" is can be improved: "A = fread(fid, [1, inf], '*char');" This avoid a data copy, casting and transpose operation, but creates a tiny [1x2] vector. But FGETL is efficient also and available in Matlab 6.5.
Más respuestas (2)
Walter Roberson
el 26 de En. de 2011
Are the quote marks and the period present in the file? For the purposes of this discussion I will presume they are not.
a = textread('inp.txt','%s','Whitespace','');
line_length = length(a{1});
space_pos = find(a{1} == ' ',1,'first');
fprintf('The actual number of characters was %d and the actual space position was %d', line_length, space_pos);
5 comentarios
Walter Roberson
el 26 de En. de 2011
Matlab 6.5? Sorry, that is before my time for functions such as textread(). This answer will not work for you.
Jan
el 26 de En. de 2011
TEXTREAD is available in Matlab 6.5, but you have to use lower case for 'whitespace'.
Gary
el 26 de En. de 2011
for a text file, doesn't each character represent 1 byte?
Does the 'dir' function exist in Matlab 6.5? In my tests creating a text file in Windows notepad, then getting the file size using Matlab's 'dir', the reported number of bytes in the file is equal to the number of characters I typed into it.
Of course, that doesn't tell you where the spaces are.
6 comentarios
Walter Roberson
el 28 de En. de 2011
The OP wants the number of characters on the first line, and gave a specific expected count that did not include any line terminators.
We saw in an earlier cssm thread that Matlab does not read past ^Z on MS Windows for a file opened as text, so any check based upon file size returned by dir() would have to account for possible line terminators and possible ^Z . I don't think it worth the effort compared to just reading the line and taking its length().
Walter Roberson
el 28 de En. de 2011
Gary, MS Windows is happy to write UTF-16 text files, so we cannot count on one character being the same as 1 byte, even without these issues of line or file terminators.
Ver también
Categorías
Más información sobre Environment and Settings en Help Center y File Exchange.
Productos
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!