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diff --git a/xpa/man/man3/xpanew.3 b/xpa/man/man3/xpanew.3 new file mode 100644 index 0000000..f4f72b6 --- /dev/null +++ b/xpa/man/man3/xpanew.3 @@ -0,0 +1,344 @@ +.\" Automatically generated by Pod::Man 2.22 (Pod::Simple 3.13) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. \*(C+ will +.\" give a nicer C++. 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Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH "NAME" +\&\fBXPANew: create a new \s-1XPA\s0 access point\fR +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <xpa.h> +\& +\& XPA XPANew(char *class, char *name, char *help, +\& int (*send_callback)(), +\& void *send_data, char *send_mode, +\& int (*rec_callback)(), +\& void *rec_data, char *rec_mode); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +Create a new \s-1XPA\s0 public access point with the class:name +identifier template +and enter this access point into the \s-1XPA\s0 name server, so that it +can be accessed by external processes. \fIXPANew()\fR returns an \s-1XPA\s0 struct. +Note that the length of the class and name designations must be less +than or equal to 1024 characters each. +.PP +The \s-1XPA\s0 name server daemon, xpans, will be started automatically if it +is not running already (assuming it can be found in the path). The +program's ip address and listening port are specified by the +environment variable \s-1XPA_NSINET\s0, which takes the form :. If +no such environment variable exists, then xpans is started on the +current machine listening on port 14285. It also uses 14286 as a +known port for its public access point (so that routines do not have +to go to the name server to find the name server ip and port!) +As of \s-1XPA\s0 2.1.1, version information is exchanged between the xpans +process and the new access point. If the access point uses an \s-1XPA\s0 +major/minor version newer than xpans, a warning is issued by both processes, +since mixing of new servers and old xpa programs (xpaset, xpaget, +xpans, etc.) is not likely to work. You can turn off the warning +message by setting the \s-1XPA_VERSIONCHECK\s0 environment variable to \*(L"false\*(R". +.PP +The help string is meant to be returned by a request from xpaget: +.PP +.Vb 1 +\& xpaget class:name \-help +.Ve +.PP +A send_callback and/or a receive_callback can be specified; at +least one of them must be specified. +.PP +A send_callback can be specified that will be executed in response to +an external request from the xpaget program, the \fIXPAGet()\fR routine, or +\&\fIXPAGetFd()\fR routine. This callback is used to send data to the +requesting client. +.PP +The calling sequence for \fIsend_callback()\fR is: +.PP +.Vb 7 +\& int send_callback(void *send_data, void *call_data, +\& char *paramlist, char **buf, size_t *len) +\& { +\& XPA xpa = (XPA)call_data; +\& ... +\& return(stat); +\& } +.Ve +.PP +The send_mode string is of the form: \*(L"key1=value1,key2=value2,...\*(R" +The following keywords are recognized: +.PP +.Vb 4 +\& key value default explanation +\& \-\-\-\-\-\- \-\-\-\-\-\-\-\- \-\-\-\-\-\-\-\- \-\-\-\-\-\-\-\-\-\-\- +\& acl true/false true enable access control +\& freebuf true/false true free buf after callback completes +.Ve +.PP +The call_data should be recast to the \s-1XPA\s0 struct as shown. In +addition, client-specific data can be passed to the callback in +send_data. +.PP +The paramlist will be supplied by the client as qualifying parameters +for the callback. There are two ways in which the \fIsend_callback()\fR +routine can send data back to the client: +.PP +1. The \fIsend_callback()\fR routine can fill in a buffer and pass back a +pointer to this buffer. An integer len also is returned to specify the +number of bytes of data in buf. \s-1XPA\s0 will send this buffer to the +client after the callback is complete. +.PP +2. The send_callback can send data directly to the client by writing +to the fd pointed by the macro: +.PP +.Vb 1 +\& xpa_datafd(xpa) +.Ve +.PP +Note that this fd is of the kind returned by \fIsocket()\fR or \fIopen()\fR. +.PP +If a buf has been allocated by a standard malloc routine, filled, and +returned to \s-1XPA\s0, then freebuf generally is set so that the buffer will +be freed automatically when the callback is completed and data has +been sent to the client. If a static buf is returned, freebuf should +be set to false to avoid a system error when freeing static storage. +Note that default value for freebuf implies that the callback will +allocate a buffer rather than use static storage. +.PP +On the other hand, if buf is dynamically allocated using a method +other than a standard malloc/calloc/realloc routine (e.g. using Perl's +memory allocation and garbage collection scheme), then it is necessary +to tell \s-1XPA\s0 how to free the allocated buffer. To do this, use the +\&\fIXPASetFree()\fR routine within your callback: +.PP +.Vb 1 +\& void XPASetFree(XPA xpa, void (*myfree)(void *), void *myfree_ptr); +.Ve +.PP +The first argument is the usual \s-1XPA\s0 handle. The second argument is the +special routine to call to free your allocated memory. The third +argument is an optional pointer. If not \s-1NULL\s0, the specified free +routine is called with that pointer as its sole argument. If \s-1NULL\s0, the +free routine is called with the standard buf pointer as its sole +argument. This is useful in cases where there is a mapping between the +buffer pointer and the actual allocated memory location, and the +special routine is expecting to be passed the former. +.PP +If, while the callback performs its processing, an error occurs that +should be communicated to the client, then the routine XPAError should be +called: +.PP +.Vb 1 +\& XPAError(XPA xpa, char *s); +.Ve +.PP +where s is an arbitrary error message. The returned error message +string will be of the form: +.PP +.Vb 1 +\& XPA$ERROR [error] (class:name ip:port) +.Ve +.PP +If the callback wants to send a specific acknowledgment message back +to the client, the routine XPAMessage can be called: +.PP +.Vb 1 +\& XPAMessage(XPA xpa, char *s); +.Ve +.PP +where s is an arbitrary error message. The returned error message +string will be of the form: +.PP +.Vb 1 +\& XPA$MESSAGE [message] (class:name ip:port) +.Ve +.PP +Otherwise, a standard acknowledgment is sent back to the client +after the callback is completed. +.PP +The callback routine should return 0 if no error occurs, or \-1 to +signal an error. +.PP +A receive_callback can be specified that will be executed in response +to an external request from the xpaset program, or the XPASet (or +\&\fIXPASetFd()\fR) routine. This callback is used to process data received +from an external process. +.PP +The calling sequence for receive_callback is: +.PP +.Vb 7 +\& int receive_callback(void *receive_data, void *call_data, +\& char *paramlist, char *buf, size_t len) +\& { +\& XPA xpa = (XPA)call_data; +\& ... +\& return(stat); +\& } +.Ve +.PP +The mode string is of the form: \*(L"key1=value1,key2=value2,...\*(R" +The following keywords are recognized: +.PP +.Vb 6 +\& key value default explanation +\& \-\-\-\-\-\- \-\-\-\-\-\-\-\- \-\-\-\-\-\-\-\- \-\-\-\-\-\-\-\-\-\-\- +\& acl true/false true enable access control +\& buf true/false true server expects data bytes from client +\& fillbuf true/false true read data into buf before executing callback +\& freebuf true/false true free buf after callback completes +.Ve +.PP +The call_data should be recast to the \s-1XPA\s0 struct as shown. In +addition, client-specific data can be passed to the callback in +receive_data. +.PP +The paramlist will be supplied by the client. In addition, if the +receive_mode keywords buf and fillbuf are true, then on entry into the +\&\fIreceive_callback()\fR routine, buf will contain the data sent by the +client. If buf is true but fillbuf is false, it becomes the callback's +responsibility to retrieve the data from the client, using the data fd +pointed to by the macro xpa_datafd(xpa). If freebuf is true, then buf +will be freed when the callback is complete. +.PP +If, while the callback is performing its processing, an error occurs +that should be communicated to the client, then the routine XPAError +can be called: +.PP +.Vb 1 +\& XPAError(XPA xpa, char *s); +.Ve +.PP +where s is an arbitrary error message. +.PP +The callback routine should return 0 if no error occurs, or \-1 to +signal an error. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +See xpa(n) for a list of \s-1XPA\s0 help pages |