sysreadFILEHANDLE,SCALAR,LENGTH,OFFSETsysreadFILEHANDLE,SCALAR,LENGTH
This function attempts to read
LENGTH
bytes of data into variable
SCALAR
from the specified
FILEHANDLE
using
read
(2). The function returns the number of bytes actually read, or 0 at EOF. It returns the undefined value on error.
SCALAR
will be grown or shrunk to the length actually read. The
OFFSET
, if specified, says where in the string to start putting the bytes, so that you can read into the middle of a string that's being used as a buffer. For an example, see
syswrite
. You should be prepared to handle the problems (like interrupted system calls) that standard I/O normally handles for you. Also, do not mix calls to
read
and
sysread
on the same filehandle unless you are into heavy wizardry (and/or pain).