| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <stdio.h> |
| |
| typedef struct { |
| char* filename; /* this file is the pipe (set by user) */ |
| char is_server; /* this is set by open_control_file */ |
| int fd; /* this is set by open_control_file */ |
| } single_instance_struct; |
| |
| /* returns fd, is_server is set to -1 if server, 0 if client */ |
| int open_control_file(single_instance_struct* str) |
| { |
| struct stat buf; |
| |
| if(stat(str->filename,&buf)) { |
| mkfifo(str->filename,128|256); |
| str->is_server=-1; |
| str->fd=open(str->filename,O_NONBLOCK|O_RDONLY); |
| } else { |
| str->fd=open(str->filename,O_NONBLOCK|O_WRONLY); |
| if(errno==ENXIO) { |
| str->is_server=-1; |
| str->fd=open(str->filename,O_NONBLOCK|O_RDONLY); |
| } else |
| str->is_server=0; |
| } |
| |
| return(str->fd); |
| } |
| |
| void delete_control_file(single_instance_struct* str) |
| { |
| remove(str->filename); |
| } |
| |
| void close_control_file(single_instance_struct* str) |
| { |
| close(str->fd); |
| } |
| |
| typedef void (*event_dispatcher)(char* message); |
| |
| int get_next_message(char* buffer,int len,single_instance_struct* str,int usecs) |
| { |
| struct timeval tv; |
| fd_set fdset; |
| int num_fds; |
| |
| FD_ZERO(&fdset); |
| FD_SET(str->fd,&fdset); |
| tv.tv_sec=0; |
| tv.tv_usec=usecs; |
| |
| num_fds=select(str->fd+1,&fdset,NULL,NULL,&tv); |
| if(num_fds) { |
| int reallen; |
| |
| reallen=read(str->fd,buffer,len); |
| if(reallen==0) { |
| close(str->fd); |
| str->fd=open(str->filename,O_NONBLOCK|O_RDONLY); |
| num_fds--; |
| } |
| buffer[reallen]=0; |
| #ifdef DEBUG_1INSTANCE |
| if(reallen!=0) rfbLog("message received: %s.\n",buffer); |
| #endif |
| } |
| |
| return(num_fds); |
| } |
| |
| int dispatch_event(single_instance_struct* str,event_dispatcher dispatcher,int usecs) |
| { |
| char buffer[1024]; |
| int num_fds; |
| |
| if((num_fds=get_next_message(buffer,1024,str,usecs)) && buffer[0]) |
| dispatcher(buffer); |
| |
| return(num_fds); |
| } |
| |
| int loop_if_server(single_instance_struct* str,event_dispatcher dispatcher) |
| { |
| open_control_file(str); |
| if(str->is_server) { |
| while(1) |
| dispatch_event(str,dispatcher,50); |
| } |
| |
| return(str->fd); |
| } |
| |
| void send_message(single_instance_struct* str,char* message) |
| { |
| #ifdef DEBUG_1INSTANCE |
| int i= |
| #endif |
| write(str->fd,message,strlen(message)); |
| #ifdef DEBUG_1INSTANCE |
| rfbLog("send: %s => %d(%d)\n",message,i,strlen(message)); |
| #endif |
| } |
| |
| #ifdef DEBUG_MAIN |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| single_instance_struct str1 = { "/tmp/1instance" }; |
| |
| void my_dispatcher(char* message) |
| { |
| #ifdef DEBUG_1INSTANCE |
| rfbLog("Message arrived: %s.\n",message); |
| #endif |
| if(!strcmp(message,"quit")) { |
| delete_control_file(str1); |
| exit(0); |
| } |
| } |
| |
| int main(int argc,char** argv) |
| { |
| int i; |
| |
| loop_if_server(str1,my_dispatcher); |
| |
| for(i=1;i<argc;i++) |
| send_event(str1,argv[i]); |
| |
| return(0); |
| } |
| |
| #endif |