Find the 137th character in a file?

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Sergio 2024-1-15

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评论： Hassaan 2024-1-26

采纳的回答： Walter Roberson

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Hi, I have a file in MATLAB that has a lot of text. I would like to find the 137th character in the file.

For this I tried the following code, but witout any luck. How can any character at a given numbered position in a text file? Thanks

>> C = char(137)
C =
''

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Dyuman Joshi 2024-1-24

I've unaccepted the incorrect answer, and accepted the correct one i.e. @Walter Roberson's.

Hassaan 2024-1-26

@Dyuman Joshi

Okay.

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采纳的回答

Walter Roberson 2024-1-16

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datastruct = load('data1.mat');
T = datastruct.T;
item_of_interest = T(137);

更多回答（3 个）

Stephen23 2024-1-15

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fnm = 'theNameOfYourFile.txt';
txt = fileread(fnm);
txt(137)

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Dyuman Joshi 2024-1-18

@Sergio, you might have accepted the wrong answer.

Stephen23 2024-1-18

@Dyuman Joshi: I agree. The only correct answer for a MAT file would be Walter Roberson's.

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Hassaan 2024-1-15

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编辑：Hassaan 2024-1-15

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Approach 1

% Open the file in read mode
fileID = fopen('yourfile.txt', 'r');
% Check if the file was opened successfully
if fileID == -1
    error('File cannot be opened.');
end
% Read the entire contents of the file into a string
fileContents = fread(fileID, '*char')';
% Close the file
fclose(fileID);
% Check if the file contains at least 137 characters
if length(fileContents) >= 137
    % Extract the 137th character
    charAt137 = fileContents(137);
else
    error('The file does not contain 137 characters.');
end
% Display the 137th character
disp(charAt137);

Make sure to replace 'yourfile.txt' with the actual name of your text file. The fread function reads the contents of the file, and the *char argument specifies that it should read the data as characters. Then, we simply index into the fileContents to find the 137th character.

Please note that this code assumes that the text file is encoded in ASCII or UTF-8 without multi-byte characters. If the text file contains multi-byte characters (like those in UTF-16 or other encodings), you will need to account for that when reading and indexing the file.

Approach 2

% Define the filename of the text file you want to read
fileName = 'FileName.txt';
% Read the entire contents of the file into a string
txtRead = fileread(fileName);
% Find and display the character at the 137th position
charAt137 = txtRead(137);
% Display the result
disp(['Character at position 137: ', charAt137]);

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If you find the solution helpful and it resolves your issue, it would be greatly appreciated if you could accept the answer. Also, leaving an upvote and a comment are also wonderful ways to provide feedback.

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Walter Roberson 2024-1-18

Neither of these approaches are suitable for the problem at hand.

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Shivam 2024-1-15

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编辑：Shivam 2024-1-15

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Hi,

I understand that you want to extract the 137th character from a .txt file.

You can refer to the following workaround to extract the 137 character from a .txt file:

file = fopen('sampleTxtFile.txt', 'r');
% Check for successfully opened file
if file == -1
    error('File cannot be opened.');
end
% Move to the desired position in the file (137th character)
fseek(file, 136, 'bof'); % 'bof' means beginning of file, indices start at 0
% Read one character from the current position
ch = fread(file, 1, 'char');
fclose(file);
% Convert the character code to a character
desiredCharacter = char(ch)