mseek — set current position in binary file.
mseek(n [,fd, flag])
a positive scalar: The offset from origin in number of bytes.
scalar. The fd parameter returned by the function mopen. -1 stands for last opened file. Default value is -1.
a string. specifies the origin. Default value 'set'.
The function mseek() sets the position of the next input or output operation
on the stream fd. The new position is at
the signed distance given by n bytes from the beginning, from
the current position, or from the end of the file, according to the
flag value which can be 'set', 'cur' or 'end'.
mseek() allows the file position indicator to be set beyond
the end of the existing data in the file. If data is later
written at this point, subsequent reads of data in the gap
will return zero until data is actually written into the
gap. mseek(), by itself, does not extend the size of the
file.
file3='test3.bin' fd1= mopen(file3,'wb'); for i=1:10, mput(i,'d'); end mseek(0); mput(678,'d'); mseek(0,fd1,'end'); mput(932,'d'); mclose(fd1) fd1= mopen(file3,'rb'); res=mget(11,'d') res1=[1:11]; res1(1)=678;res1($)=932; if res1<>res ;write(%io(2),'Bug');end; mseek(0,fd1,'set'); // trying to read more than stored data res1=mget(100,'d',fd1); if res1<>res ;write(%io(2),'Bug');end; meof(fd1) mclearerr(fd1) mclose(fd1);