Provided by: libxpa-dev_2.1.18-4_amd64 bug


       XPASetFd -  send data from stdin to one or more XPA servers


         #include <xpa.h>

         int XPASetFd(XPA xpa,
                      char *template, char *paramlist, char *mode,
                      int fd, char **names, char **messages, int n)


       Read data from a standard I/O fd and send it to one or more XPA servers whose class:name
       identifier matches the specified template.

       A template of the form "class1:name1" is sent to the XPA name server, which returns a list
       of at most n matching XPA servers.  A connection is established with each of these servers
       and the paramlist string is passed to the server as the data transfer request is
       initiated. If an XPA struct is passed to the call, then the persistent connections are
       updated as described above. Otherwise, temporary connections are made to the servers
       (which will be closed when the call completes).

       The XPASetFd() routine then reads bytes from the specified fd until EOF and sends these
       bytes to the XPA servers.  The final parameter n specifies the maximum number of servers
       to contact.  A string containing the class:name and ip:port of each server is returned in
       the name array.  If a given server returned an error, then the error message will be
       stored in the associated element of the messages array.  NB: if specified, the name and
       messages arrays must be of size n or greater.

       The return value will contain the actual number of servers that were processed.  This
       value thus will hold the number of valid entries in the names and messages arrays, and can
       be used to loop through these arrays.  In names and/or messages is NULL, no information is
       passed back in that array.

       The mode string is of the form: "key1=value1,key2=value2,..."  The following keywords are

         key           value           default         explanation
         ------        --------        --------        -----------
         ack           true/false      true            if false, don't wait for ack from server (after callback completes)
         verify        true/false      false           send buf from XPASet[Fd] to stdout

       The ack keyword is useful in cases where one does not want to wait for the server to
       complete, e.g. is a lot of processing needs to be done on the passed data or when the
       success of the server operation is not relevant to the client.

       Example -

         #include <xpa.h>

         #define NXPA 10
         int  i, got;
         int fd;
         char *names[NXPA];
         char *messages[NXPA];
         fd = open(...);
         got = XPASetFd(NULL, "ds9", "fits", NULL, fd, names, messages, NXPA);
         for(i=0; i<got; i++){
           if( messages[i] != NULL ){
             /* error processing */
             fprintf(stderr, "ERROR: %s (%s)\n", messages[i], names[i]);
           if( names[i] )
           if( messages[i] )


       See xpa(7) for a list of XPA help pages