LIBINN(3)
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
limits 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 contain-
ing the text of the article; the end of the headers is
indicated by a blank line -- two consecutive \n charac-
ters.
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
FromServer and ToServer parameters should be FILE's con-
nected to the NNTP server for input and output, respec-
tively. 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 argu-
ment 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 Distribu-
tion 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 news-
groups have been checked. DDstart begins the parsing. It
returns a pointer to an opaque handle that should be used
on subsequent calls. The FromServer and ToServer parame-
ters 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, other-
wise 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 configu-
ration parameter. See inn.conf(5) for details on the
parameters 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 mod-
erators(5) for details on how the address is determined.
GetModeratorAddress does no checking to see if the speci-
fied group is actually moderated. The returned value
points to static space that is reused on subsequent calls.
The FromServer and ToServer parameters should be FILE's
connected to the NNTP server for input and output, respec-
tively. 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 cur-
rent process and any children it may have spawned. It
gets the values by doing a getrusage(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 comparing 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
ToServerp will be filled in with FILE's which can be used
to communicate 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
limitations 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 fail-
ure, 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 con-
nected 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 character 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 mem-
ory, 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 lt;rsalz@uunet.uu.net for InterNet-
News. This is revision 1.21, dated 1996/07/12.
SEE ALSO
active(5) dbz(3z) parsedate(3) inn.conf(5) innd-
comm(3) moderators(5) passwd.nntp(5).