00001 /*
00002     FIFO-based server
00003     AUP2, Sec. 7.02.2
00004 
00005     Copyright 2003 by Marc J. Rochkind. All rights reserved.
00006     May be copied only for purposes and under conditions described
00007     on the Web page www.basepath.com/aup/copyright.htm.
00008 
00009     The Example Files are provided "as is," without any warranty;
00010     without even the implied warranty of merchantability or fitness
00011     for a particular purpose. The author and his publisher are not
00012     responsible for any damages, direct or incidental, resulting
00013     from the use or non-use of these Example Files.
00014 
00015     The Example Files may contain defects, and some contain deliberate
00016     coding mistakes that were included for educational reasons.
00017     You are responsible for determining if and how the Example Files
00018     are to be used.
00019 
00020 */
00021 #include "defs.h"
00022 #include "smsg.h"
00023 
00024 #define WANT_BUGFIX
00025 
00026 /* Server */
00027 /* Assumes no partial reads */
00028 /*[main]*/
00029 int main(void)
00030 {
00031     int fd_server, fd_client, i;
00032 #ifdef WANT_BUGFIX
00033     int fd_server_w;
00034 #endif
00035     ssize_t nread;
00036     struct simple_message msg;
00037     char fifo_name[100];
00038 
00039     printf("server started\n");
00040     if (mkfifo(SERVER_FIFO_NAME, PERM_FILE) == -1 && errno != EEXIST)
00041         EC_FAIL
00042     // will block waiting for writer
00043     ec_neg1( fd_server = open(SERVER_FIFO_NAME, O_RDONLY) )
00044 #ifdef WANT_BUGFIX
00045     ec_neg1( fd_server_w = open(SERVER_FIFO_NAME, O_WRONLY) )
00046 #endif
00047     while (true) {
00048         /* will return EOF if no writers -- a bug! */
00049         ec_neg1( nread = read(fd_server, &msg, sizeof(msg)) )
00050         //printf("back from read; nread = %d\n", nread);
00051         if (nread == 0) {
00052             errno = ENETDOWN;
00053             EC_FAIL
00054         }
00055         for (i = 0; msg.sm_data[i] != '\0'; i++)
00056             msg.sm_data[i] = toupper(msg.sm_data[i]);
00057         ec_false( make_fifo_name(msg.sm_clientpid, fifo_name,
00058           sizeof(fifo_name)) )
00059         ec_neg1( fd_client = open(fifo_name, O_WRONLY) )
00060         ec_neg1( write(fd_client, &msg, sizeof(msg)) )
00061         ec_neg1( close(fd_client) )
00062     }
00063     /* never actually get here */
00064     ec_neg1( close(fd_server) )
00065 #ifdef WANT_BUGFIX
00066     ec_neg1( close(fd_server_w) )
00067 #endif
00068     exit(EXIT_SUCCESS);
00069 
00070 EC_CLEANUP_BGN
00071     exit(EXIT_FAILURE);
00072 EC_CLEANUP_END
00073 }
c7/smsg_server.c
