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syswrite

See the current Perl documentation for syswrite.

Here is our local, out-dated (pre-5.6) version:


syswrite - fixed-length unbuffered output to a filehandle



syswrite FILEHANDLE,SCALAR,LENGTH,OFFSET

syswrite FILEHANDLE,SCALAR,LENGTH



Attempts to write LENGTH bytes of data from variable SCALAR to the specified FILEHANDLE, using the system call write(2). It bypasses stdio, so mixing this with reads (other than sysread()), print(), write(), seek(), or tell() may cause confusion because stdio usually buffers data. Returns the number of bytes actually written, or undef if there was an error. If the LENGTH is greater than the available data in the SCALAR after the OFFSET, only as much data as is available will be written.

An OFFSET may be specified to write the data from some part of the string other than the beginning. A negative OFFSET specifies writing that many bytes counting backwards from the end of the string. In the case the SCALAR is empty you can use OFFSET but only zero offset.