fgetl - Read line from file, removing newline characters - MATLAB (original) (raw)

Main Content

Read line from file, removing newline characters

Syntax

Description

tline = fgetl([fileID](#d126e531458)) returns the next line of the specified file, removing the newline characters.

• If the file is nonempty, then fgetl returnstline as a character vector.
• If the file is empty and contains only the end-of-file marker, thenfgetl returns tline as a numeric value -1.

example

Examples

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Read a single line from a file, first excluding newline characters, and then including them. Use the following file.

To read the first line from the file badpoem.txt, use fopen to open the file. Then read the first line using fgetl, which excludes the newline character.

fid = fopen('badpoem.txt'); line_ex = fgetl(fid) % read line excluding newline character

line_ex = 'Oranges and lemons,'

To reread the same line from the file, first reset the read position indicator back to the beginning of the file.

Use the fgets function to read the first line from the file badpoem.txt, which reads the line including the newline character.

line_in = fgets(fid) % read line including newline character

line_in = 'Oranges and lemons, '

Compare the output by examining the lengths of the lines returned by the fgetl and fgets functions.

fgetl returns an output that displays in one line, while fgets returns an output that includes the newline character and, therefore, displays it in two lines.

line_ex = 'Oranges and lemons,'

line_in = 'Oranges and lemons, '

Close the file.

Input Arguments

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File identifier of an open file, specified as an integer. Before usingfgetl to read a line from the file, you must usefopen to open the file and obtain its identifier fileID.

Data Types: double

Tips

• fgetl reads characters using the encoding scheme associated with the file. To specify the encoding scheme, usefopen.
• When fgetl encounters the ASCII characters in the order0A 0D, which are a line feed followed by a carriage return, it will read them as a single ASCII newline character.
• To read lines from a file while keeping newline characters, use fgets.

Extended Capabilities

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Usage notes and limitations:

• If the function fgetl does not read content from the file, then the generated code reports either an error or returns an empty value instead of returning -1.
• If the function fgetl reads a null byte, the returned values might be truncated.

Version History

Introduced before R2006a

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You can read data from primary online sources by performing low-level file read operations over an internet URL.

This function supports thread-based environments.