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 specified
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
FromServer 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 subsequent 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 configuration
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
moderators(5) for details
on how the address is determined.
GetModeratorAddress 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
FromServer 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
parameters 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
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
taking the value of the ``tm_gmtoff'' field, negating it, and dividing it by
60. 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
GetConfigValue
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
conventions 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 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 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).