NAME
libinn - InterNetNews library routines
SYNOPSIS
#include "libinn.h"
typedef struct _TIMEINFO {
time_t time;
long usec;
long tzone;
} TIMEINFO;
char *
GenerateMessageID()
void
HeaderCleanFrom(from)
char *from;
char *
HeaderFind(Article, Header, size)
char *Article;
char *Header;
int size;
FILE *
CAopen(FromServer, ToServer)
FILE *FromServer;
FILE *ToServer;
FILE *
CAlistopen(FromServer, ToServer, request)
FILE *FromServer;
FILE *ToServer;
char *request;
void
CAclose()
struct _DDHANDLE *
DDstart(FromServer, ToServer)
FILE *FromServer;
FILE *ToServer;
void
DDcheck(h, group)
DDHANDLE *h;
char *group;
char *
DDend(h)
DDHANDLE *h;
void
CloseOnExec(fd, flag)
int fd;
int flag;
int
SetNonBlocking(fd, flag)
int fd;
int flag;
int
LockFile(fd, flag)
int fd;
int flag;
char *
GetConfigValue(value)
char *value;
char *
GetFileConfigValue(value)
char *value;
char *
GetFQDN()
char *
GetModeratorAddress(FromServer, ToServer, group)
FILE *FromServer;
FILE *ToServer;
char *group;
int
GetResourceUsage(usertime, systime)
double *usertime;
double *systime;
int
GetTimeInfo(now)
TIMEINFO *now;
int
NNTPlocalopen(FromServerp, ToServerp, errbuff)
FILE **FromServerp;
FILE **ToServerp;
char *errbuff;
int
NNTPremoteopen(FromServerp, ToServerp, errbuff)
FILE **FromServerp;
FILE **ToServerp;
char *errbuff;
int
NNTPconnect(host, FromServerp, ToServerp, errbuff)
char *host;
FILE **FromServerp;
FILE **ToServerp;
char *errbuff;
int
NNTPcheckarticle(text)
char *text;
int
NNTPsendarticle(text, ToServer, Terminate)
char *text;
FILE *ToServer;
int Terminate;
int
NNTPsendpassword(server, FromServer, ToServer)
char *server;
FILE *FromServer;
FILE *ToServer;
void
Radix32(value, p)
unsigned long value;
char *p;
char *
ReadInFile(name, Sbp)
char *name;
struct stat *Sbp;
char *
ReadInDescriptor(fd, Sbp)
int fd;
struct stat *Sbp;
char *
INNVersion()
DESCRIPTION
Libinn is a library of utility routines for manipulating
Usenet articles and related data. It is not necessary to
use the header file libinn.h; if it is not available, it is
only necessary to properly declare the TIMEINFO datatype, as
given above.
GenerateMessageID uses the current time, process-ID, and
fully-qualified domain name of the local host to create a
Message-ID header that is highly likely to be unique. The
returned value points to static space that is reused on
subsequent calls.
HeaderCleanFrom removes the extraneous information from the
value of a ``From'' or ``Reply-To'' header and leaves just
the official mailing address. In particular, the following
transformations are made to the from parameter:
address --> address
address (stuff) --> address
stuff <address> --> address
The transformations are simple, based on RFC 1036 which lim-
its the format of the header.
HeaderFind searches through Article looking for the speci-
fied Header. Size should be the length of the header name.
It returns a pointer to the value of the header, skipping
leading whitespace, or NULL if the header cannot be found.
Article should be a standard C string containing the text of
the article; the end of the headers is indicated by a blank
line - two consecutive \n characters.
CAopen and CAclose provide news clients with access to the
active file; the ``CA'' stands for Client Active. CAopen
opens the active(5) file for reading. It returns a pointer
to an open FILE, or NULL on error. If a local or NFS-
mounted copy exists, CAopen will use that file. The From-
Server and ToServer parameters should be FILE's connected to
the NNTP server for input and output, respectively. See
NNTPremoteopen or NNTPlocalopen, below. If either parameter
is NULL, then CAopen will just return NULL if the file is
not locally available. If they are not NULL, CAopen will
use them to query the NNTP server using the ``list'' command
to make a local temporary copy.
The CAlistopen sends a ``list'' command to the server and
returns a temporary file containing the results. The
request parameter, if not NULL, will be sent as an argument
to the command. Unlike CAopen, this routine will never use
a locally-available copy of the active file.
CAclose closes the active file and removes any temporary
file that might have been created by CAopen or CAlistopen.
CloseOnExec can make a descriptor ``close-on-exec'' so that
it is not shared with any child processes. If the flag is
non-zero, the file is so marked; if zero, the ``close-on-
exec'' mode is cleared.
DDstart, DDcheck, and DDend are used to set the Distribution
header; the ``DD'' stands for Default Distribution. The
distrib.pats(5) file is consulted to determine the proper
value for the Distribution header after all newsgroups have
been checked. DDstart begins the parsing. It returns a
pointer to an opaque handle that should be used on subse-
quent calls. The FromServer and ToServer parameters should
be FILE's connected to the NNTP server for input and output,
respectively. If either parameter is NULL, then an empty
default will ultimately be returned if the file is not
locally available.
DDcheck should be called with the handle, h, returned by
DDstart and a newgroups, group, to check. It can be called
as often as necessary.
DDend releases any state maintained in the handle and
returns an allocated copy of the text that should be used
for the Distribution header.
SetNonBlocking enables (if flag is non-zero) or disables (if
flag is zero) non-blocking I/O on the indicated descriptor.
It returns -1 on failure or zero on success.
LockFile tries to lock the file descriptor fd. If flag is
non-zero it will block until the lock can be made, otherwise
it will return -1 if the file cannot be locked. It returns
-1 on failure or zero on success.
GetConfigValue returns the value of the specified configura-
tion parameter. See inn.conf(5) for details on the parame-
ters and their interpretation. The returned value points to
static space that is reused on subsequent calls.
GetFileConfigValue returns the specified configuration
parameter from the inn.conf file without checking for any
defaults. The returned value points to static space that is
reused on subsequent calls, or NULL if the value is not
present.
GetFQDN returns the fully-qualified domain name of the local
host. The returned value points to static space that is
reused on subsequent calls, or NULL on error.
GetModeratorAddress returns the mailing address of the
moderator for specified group or NULL on error. See modera-
tors(5) for details on how the address is determined. Get-
ModeratorAddress does no checking to see if the specified
group is actually moderated. The returned value points to
static space that is reused on subsequent calls. The From-
Server and ToServer parameters should be FILE's connected to
the NNTP server for input and output, respectively. If
either of these parameters is NULL, then an attempt to get
the list from a local copy is made.
GetResourceUsage fills in the usertime and systime parame-
ters with the total user and system time used by the current
process and any children it may have spawned. It gets the
values by doing a ds R$ times (2) system call. It returns
-1 on failure, or zero on success.
GetTimeInfo fills in the now parameter with information
about the current time and tzone. The ``time'' and ``usec''
fields will be filled in by a call to gettimeofday(2). The
``tzone'' field will be filled in with the current offset
from GMT. This is done by calling localtime(3) and compar-
ing the value with that returned by a call to gmtime(3). For
efficiency, the ``tzone'' field is only recalculated if more
than an hour pass passed since the last time GetTimeInfo has
been called. This routine returns -1 on failure, or zero on
success.
NNTPlocalopen opens a connection to the private port of an
InterNetNews server running on the local host. It returns
-1 on failure, or zero on success. FromServerp and ToSer-
verp will be filled in with FILE's which can be used to com-
municate with the server. Errbuff can either be NULL or a
pointer to a buffer at least 512 bytes long. If not NULL,
and the server refuses the connection, then it will be
filled in with the text of the server's reply. This routine
is not for general use.
NNTPremoteopen does the same except that it calls GetCon-
figValue to find the name of the local server, and opens a
connection to the standard NNTP port. Any client program
can use this routine. It returns -1 on failure, or zero on
success.
NNTPconnect is the same as NNTPremoteopen except that the
desired host is given as the host parameter.
NNTPcheckarticle verifies that the text meets the NNTP limi-
tations on line length. It returns -1 on failure, or zero
if the text is valid.
NNTPsendarticle writes text on ToServer using NNTP conven-
tions for line termination. The text should consist of one
or more lines ending with a newline. If Terminate is non-
zero, then the routine will also write the NNTP data-
termination marker on the stream. It returns -1 on failure,
or zero on success.
NNTPsendpassword sends authentication information to an NNTP
server by finding the appropriate entry in the
passwd.nntp(5) file. Server contains the name of the host;
GetConfigValue will be used if server is NULL. FromServer
and ToServer should be FILE's that are connected to the
server. No action is taken if the specified host is not
listed in the password file.
Radix32 converts the number in value into a radix-32 string
into the buffer pointed to by p. The number is split into
five-bit pieces and each pieces is converted into a charac-
ter using the alphabet 0..9a..v to represent the numbers
0..32. Only the lowest 32 bits of value are used, so p need
only point to a buffer of eight bytes (seven characters and
the trailing \0).
ReadInFile reads the file named name into allocated memory,
appending a terminating \0 byte. It returns a pointer to
the space, or NULL on error. If Sbp is not NULL, it is
taken as the address of a place to store the results of a
stat(2) call.
ReadInDescriptor performs the same function as ReadInFile
except that fd refers to an already-open file.
INNVersion returns a pointer to a string identifying the INN
version, suitable for printing in logon banners.
EXAMPLES
char *p;
char *Article;
char buff[256];
FILE *F;
FILE *ToServer;
FILE *FromServer;
if ((p = HeaderFind(Article, "From", 4)) == NULL)
Fatal("Can't find From line");
(void)strcpy(buff, p);
HeaderCleanFrom(buff);
if ((F = CAopen(FromServer, ToServer)) == NULL)
Fatal("Can't open active file");
/* Don't pass the file on to our children. */
CloseOnExec(fileno(F), 1);
/* Make a local copy. */
p = ReadInDescriptor(fileno(F), (struct stat *)NULL);
/* Close the file. */
CAclose();
if (NNTPremoteopen(&FromServer, &ToServer) < 0)
Fatal("Can't connect to server");
if ((p = GetModeratorAddress("comp.sources.unix")) == NULL)
Fatal("Can't find moderator's address");
HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews.
This is revision 1.21, dated 1996/07/12.
SEE ALSO
active(5), dbz(3z), parsedate(3), inn.conf(5), inndcomm(3),
moderators(5), passwd.nntp(5).
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