Node:Binary I/O, Next:Temporary Files, Previous:String Input Conversions, Up:C-Style I/O Functions
Octave can read and write binary data using the functions fread
and fwrite
, which are patterned after the standard C functions
with the same names. The are able to automatically swap the byte order
of integer data and convert among ths supported floating point formats
as the data are read.
[val, count] = fread (fid, size, precision, skip, arch) | Built-in Function |
Read binary data of type precision from the specified file ID
fid.
The optional argument size specifies the amount of data to read and may be one of
If size is omitted, a value of The optional argument precision is a string specifying the type of data to read and may be one of
The default precision is The precision argument may also specify an optional repeat
count. For example, The precision argument may also specify a type conversion.
For example, The conversion and repeat counts may be combined. For example,
The optional argument skip specifies the number of bytes to skip
after each element (or block of elements) is read. If it is not
specified, a value of 0 is assumed. If the final block read is not
complete, the final skip is omitted. For example,
fread (f, 10, "3*single=>single", 8) will omit the final 8-byte skip because the last read will not be a complete block of 3 values. The optional argument arch is a string specifying the data format for the file. Valid values are
Conversions are currently only supported for The data read from the file is returned in val, and the number of
values read is returned in |
count = fwrite (fid, data, precision, skip, arch) | Built-in Function |
Write data in binary form of type precision to the specified file
ID fid, returning the number of values successfully written to the
file.
The argument data is a matrix of values that are to be written to the file. The values are extracted in column-major order. The remaining arguments precision, skip, and arch are
optional, and are interpreted as described for The behavior of |