Section: Input/Ouput Functions
fp = fopen(fname,mode,byteorder)
Here fname
is a string containing the name of the file to be
opened. mode
is the mode string for the file open command.
The first character of the mode string is one of the following:
'r'
Open file for reading. The file pointer is placed at
the beginning of the file. The file can be read from, but
not written to.
'r+'
Open for reading and writing. The file pointer is
placed at the beginning of the file. The file can be read
from and written to, but must exist at the outset.
'w'
Open file for writing. If the file already exists, it is
truncated to zero length. Otherwise, a new file is
created. The file pointer is placed at the beginning of
the file.
'w+'
Open for reading and writing. The file is created if
it does not exist, otherwise it is truncated to zero
length. The file pointer placed at the beginning of the file.
'a'
Open for appending (writing at end of file). The file is
created if it does not exist. The file pointer is placed at
the end of the file.
'a+'
Open for reading and appending (writing at end of file). The
file is created if it does not exist. The file pointer is
placed at the end of the file.
'le','ieee-le','little-endian','littleEndian','little'
'be','ieee-be','big-endian','bigEndian','big'
fread
,
fwrite
, or fclose
for file access.
Note that three handles are assigned at initialization time:
3
.
fopen
. First, we create a new
file, which we want to be little-endian, regardless of the type of the machine.
We also use the fwrite
function to write some floating point data to
the file.
--> fp = fopen('test.dat','wb','ieee-le') fp = 8 --> fwrite(fp,float([1.2,4.3,2.1])) ans = 3 --> fclose(fp) ans = 0 --> quit
Next, we open the file and read the data back
--> fp = fopen('test.dat','rb','ieee-le') fp = 8 --> fread(fp,[1,3],'float') ans = 1.2000 4.3000 2.1000 --> fclose(fp) ans = 0 --> quit
Now, we re-open the file in append mode and add two additional float
s to the
file.
--> fp = fopen('test.dat','a+','le') fp = 8 --> fwrite(fp,float([pi,e])) ans = 2 --> fclose(fp) ans = 0 --> quit
Finally, we read all 5 float
values from the file
--> fp = fopen('test.dat','rb','ieee-le') fp = 8 --> fread(fp,[1,5],'float') ans = 1.2000 4.3000 2.1000 3.1416 2.7183 --> fclose(fp) ans = 0 --> quit