MATLAB Programming

Using Low-Level File I/O Functions
Using Low-Level File I/O Functions
MATLAB includes a set of low-level file I/O functions that are based on the I/O
functions of the ANSI Standard C Library. If you know C, you are probably
familiar with these routines. This section covers
• “Opening Files” on page 6-104
• “Reading Binary Data” on page 6-106
• “Writing Binary Data” on page 6-108
• “Controlling Position in a File” on page 6-108
• “Reading Strings Line by Line from Text Files” on page 6-110
• “Reading Formatted ASCII Data” on page 6-111
• “Writing Formatted Text Files” on page 6-113
• “Closing a File” on page 6-114
TheMATLABfileI/OfunctionsusethesameprogrammingmodelastheC
language routines. To read or write data, you perform these steps:
1 Open the file, using fopen. fopen returns a file identifier that you use with
all the other low-level file I/O routines.
2 Operate on the file.
a Read binary data, using fread.
b Write binary data, using fwrite.
c
Read text strings from a file line-by-line, using fgets or fgetl.
d Read formatted ASCII data, using fscanf.
e
Write formatted ASCII data, using fprintf.
3 Close the file, using fclose.
This section also describes how these functions affect the current position
inthefilewhere read or write operations happen and how you can change
the position in thefile.
6-103