QIO(3)QIO(3)NAMEqio - quick I/O part of InterNetNews library
SYNOPSIS
#include "qio.h"
QIOSTATE *
QIOopen(name)
char *name;
QIOSTATE *
QIOfdopen(fd)
int fd;
void
QIOclose(qp)
QIOSTATE *qp;
char *
QIOread(qp)
QIOSTATE *qp;
int
QIOlength(qp)
QIOSTATE *qp;
int
QIOtoolong(qp)
QIOSTATE *qp;
int
QIOerror(qp)
QIOSTATE *qp;
int
QIOtell(qp)
QIOSTATE *qp;
int
QIOrewind(qp)
QIOSTATE *qp;
int
QIOfileno(qp)
QIOSTATE *qp;
DESCRIPTION
The routines described in this manual page are part of
libstorage(3). They are used to provide quick read access
to files or articles specified with tokens. All routines
are not available for token. The letters ``QIO'' stand
for Quick I/O.
QIOopen opens the file name for reading. If name is the
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QIO(3)QIO(3)
token of an article, QIOopen calls SMretrieve. If
<HAVE_ST_BLKSIZE in include/config.h> is defined, QIOopen
will call stat(2) and use the returned block size; if that
fails (or <HAVE_ST_BLKSIZE in include/config.h> is not
defined) it will use QIO_BUFFER. It returns NULL on
error, or a pointer to a handle to be used in other calls.
QIOfdopen performs the same function except that fd refers
to an already-open descriptor.
QIOclose closes the open file and releases any resources
used by it.
QIOread returns a pointer to the next line in the file.
The trailing newline will be replaced with a \0. If EOF
is reached, an error occurs, or if the line is longer than
the buffer, QIOread returns NULL.
After a successful call to QIOread, QIOlength will return
the length of the current line.
The functions QIOtoolong and QIOerror can be called after
QIOread returns NULL to determine if there was an error,
or if the line was too long. If QIOtoolong returns non-
zero, then the current line did not fit in the buffer, and
the next call to QIOread will try read the rest of the
line. Long lines can only be discarded. If QIOerror
returns non-zero, then a serious I/O error occurred.
QIOtell returns the lseek(2) offset at which the next line
will start.
QIOrewind sets the read pointer back to the beginning of
the file.
QIOfileno returns the descriptor of the open file.
QIOlength, QIOtoolong, QIOerror, QIOtell, and QIOfileno
are implemented as macro's defined in the header file.
EXAMPLE
QIOSTATE *h;
long offset;
char *p;
h = QIOopen("/etc/motd", QIO_BUFFER);
for (offset = QIOtell(h); (p = QIOread(h)) != NULL; offset = QIOtell(h))
printf("At %ld, %s\n", offset, p);
if (QIOerror(h)) {
perror("Read error");
exit(1);
}
QIOclose(h);
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QIO(3)QIO(3)HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNet-
News. This is revision 1.1.2.1, dated 1999/06/12.
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