moved files to include; moved a file to examples/

1 files changed, 141 insertions, 0 deletions

diff --git a/examples/1instance.c b/examples/1instance.c
new file mode 100644
index 0000000..8feadb5
--- /dev/null
+++ b/examples/1instance.c
@@ -0,0 +1,141 @@
+#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) fprintf(stderr,"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
+  fprintf(stderr,"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
+  fprintf(stderr,"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