skiprec.3

speech signal process tools

.\" Copyright (c) 1987-1990 Entropic Speech, Inc.
.\" Copyright (c) 1990-1997 Entropic Research Laboratory, Inc. All rights reserved.
.\" @(#)skiprec.3	1.6 30 Sep 1997 ESI/ERL
.ds ]W (c) 1997 Entropic Research Laboratory, Inc.
.TH SKIPREC 3\-ESPSu 30 Sep 1997
.SH NAME
skiprec \- skip fixed-length records in a file

fea_skiprec \- skip records in a file
.SH SYNOPSIS
.nf
.ft B
void
skiprec(stream, nrec, size)
FILE *stream;
long nrec;
int size;

void
fea_skiprec(stream, nrecs, hdr)
FILE *stream;
long nrecs;
struct header *hdr;
.ft
.fi
.SH DESCRIPTION
.PP
.I skiprec
changes position in a binary file.
It skips forward
.I nrec
records, each containing
.I size
bytes.
It first tries to accomplish this with a disk seek operation.
If the seek would change the position to beyond the end of the file,
the position is left at the end of the file.
If this fails (for instance,
.I stream
may be a pipe) and
.I nrec
is nonnegative, it skips forward by reading the file and discarding the output.
.PP
.I fea_skiprec
changes position in a file described by the ESPS header structure
indicated by
.I hdr.
When the file is an ordinary FEA file
.RI ( FEA (5\-ESPS)),
the effect is simply that of
.LP
.RS
.nf
.if t .ft I
skiprec(stream, nrecs, size_rec(hdr));
.if t .ft P
.fi
.RE
.LP
However,
.I fea_skiprec
also works when
.RI * hdr
is a surrogate header created by
.IR read_header (3\-ESPS)
upon reading a NIST
.I Sphere
file or an Entropic
.I Esignal
file.
In those cases
.I fea_skiprec
calls the appropriate
.I Sphere
or
.I Esignal
routine.
It can thus handle certain formats
that do not store records in fixed-size chunks.
Examples are
.I Sphere
variable-rate compressed formats and the
.I Esignal
ASCII representation.
Being more general than the combination of
.I skiprec
with
.IR size_rec (3\-ESPS),
the function
.I fea_skiprec
is to be preferred.
.SH DIAGNOSTICS
If a seek error occurs and
.I nrec
is negative,
.I skiprec
prints an error message on the error output and exits.
An assertion failure
.RI ( spsassert (3\-ESPS))
occurs if
.I skiprec
is called with a NULL argument
.I stream
or a negative argument
.I siz,
or if
.I fea_skiprec
is called with a NULL argument
.I stream
or a NULL argument
.I hdr.
.SH SEE ALSO
.IR read_header (3\-ESPS),
.IR size_rec (3\-ESPSu),
.IR spsassert (3\-ESPS),
.br
.IR FEA (5\-ESPS)
.SH AUTHOR