逗點大的雨滴

parent process create child process

add value util bigger than five and then exit

#include <unistd.h> /* Symbolic Constants */
#include <sys/types.h> /* Primitive System Data Types */
#include <errno.h> /* Errors */
#include <stdio.h> /* Input/Output */
#include <sys/wait.h> /* Wait for Process Termination */
#include <stdlib.h> /* General Utilities */

int main()
{
   pid_t childpid; /* variable to store the child's pid */
   int value=0; /* parent process: child's exit status */

   /* only 1 int variable is needed because each process would have its
   * own instance of the variable
   * here, 2 int variables are used for clarity */

   /* now create new process */
   childpid = fork();

   if (childpid >= 0) /* fork succeeded */
   {
   if (childpid == 0) /* fork() returns 0 to the child process */
   {
   printf("Child: Here's my PID: %d\n", getpid());
   while(value<5){
   value+=1;
   printf("Child value= %d\n",value);
   sleep(1);
   }
   printf("Child: Goodbye!\n");
   exit(0);
   }
   else /* fork() returns new pid to the parent process */
   {
   printf("Parenet: Here's my PID: %d\n", getpid());
   while(value<5){
   value+=1;
   printf("Parent value= %d\n",value);
   sleep(1);
   }
   printf("PARENT: Goodbye!\n");
   exit(0); /* parent exits */
   }
   }
   else /* fork returns -1 on failure */
   {
   perror("fork"); /* display error message */
   exit(0);
   }

makefile

fork:fork.o
   cc -o fork fork.o

fork.o:fork.c
   cc -c fork.c

clean:
   rm -rf fork *.o

繼續閱讀...

client result socketfd 4

XXXXX:~/socket/select/test1_add_strtok$ ./client

input message to server or client : ex: to clientid message
recv message : online client id 4
recv message : welcome to myserver,your client id is 4
to 4 aaaa

input message to server or client : ex: to clientid message
recv message : aaaa From client 4 message
recv message : to 4 aaaa
recv message : online client id 4 5
recv message : abc From client 5 message

client result sockfd 5

xxxx:~/socket/select/test1_add_strtok$ ./client

input message to server or client : ex: to clientid message
recv message : online client id 4 5
recv message : welcome to myserver,your client id is 5
to 4 abc

input message to server or client : ex: to clientid message
recv message : to 4 abc

server result

steven@73-247:~/socket/select$ ./server
Waiting on select()...
  Listening client socket 3 is readable
  New incoming connection - 4
Waiting on select()...
  Descriptor 4 is readable
  server recv: to 4 aaaa
Waiting on select()...
  Listening client socket 3 is readable
  New incoming connection - 5
Waiting on select()...
  Descriptor 5 is readable
  server recv: to 4 abc
Waiting on select()...

server code

steven@73-247:~/socket/select$ cat server.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <errno.h>
#include <string.h>

#define SERVER_PORT 1234

#define TRUE 1
#define FALSE 0
void int2str(int i, char *s) {
  sprintf(s,"%d",i);
}
main (int argc, char *argv[])
{
   int i, len, rc, on = 1,m;
   int listen_sd, max_sd, new_sd;
   int tok_i;
   int desc_ready, end_server = FALSE;
   int close_conn;
   char buffer[80],temp_buffer[80],s[80];
   struct sockaddr_in addr;
   struct timeval timeout;
   fd_set master_set,working_set;

   char clist[80];
   int loop = 4,loop_i = 4;
   char *tok;
   char to_mes[80];
   int count=0,to=0,to_cid;

   /*************************************************************/
   /* Create an AF_INET stream socket
   /*************************************************************/
   listen_sd = socket(PF_INET, SOCK_STREAM, 0);
   if (listen_sd < 0)
   {
   perror("socket() failed");
   exit(-1);
   }

   /*************************************************************/
   /* Allow socket descriptor to be reuseable */
   /*On success, zero is returned. On error, -1 is returned */
   /*************************************************************/
   rc = setsockopt(listen_sd, SOL_SOCKET, SO_REUSEADDR,(char *)&on, sizeof(on));
   if (rc < 0)
   {
   perror("setsockopt() failed");
   close(listen_sd);
   exit(-1);
   }

   /*************************************************************/
   /* Set socket to be non-blocking. All of the sockets for */
   /* the incoming connections will also be non-blocking since */
   /* they will inherit that state from the listening socket. */
   /*on success zero is returned. On error, -1 is returned */
   /*int ioctl(int fd, unsigned long request, char *arg) */
   /*FLOCLEX : set the close-on-exec flag for file descriptor */
   /*FIONCLEX : clear the close-on-exec flag for file descriptor*/
   /*FIOASYNC : allows the receipt of asynchronous I/O signals */
   /*FIONBIO : File IOctl Nonblock I/O */
   /*************************************************************/
   rc = ioctl(listen_sd, FIONBIO, (char *)&on);
   if (rc < 0)
   {
   perror("ioctl() failed");
   close(listen_sd);
   exit(-1);
   }

   /*************************************************************/
   /* Bind the socket */
   /*************************************************************/
   memset(&addr, 0, sizeof(addr));
   addr.sin_family = AF_INET;
   addr.sin_addr.s_addr = htonl(INADDR_ANY);
   addr.sin_port = htons(SERVER_PORT);
   rc = bind(listen_sd,(struct sockaddr *)&addr, sizeof(addr));
   if (rc < 0)
   {
   perror("bind() failed");
   close(listen_sd);
   exit(-1);
   }

   /*************************************************************/
   /* Set the listen back log */
   /*************************************************************/
   rc = listen(listen_sd, 32);
   if (rc < 0)
   {
   perror("listen() failed");
   close(listen_sd);
   exit(-1);
   }

   /*************************************************************/
   /* Initialize the master fd_set */
   /*************************************************************/
   FD_ZERO(&master_set);
   max_sd = listen_sd;

   /*************************************************************/
   /* Initialize the timeval struct to 3 minutes. If no */
   /* activity after 3 minutes this program will end. */
   /*************************************************************/

   /*************************************************************/
   /* Loop waiting for incoming connects or for incoming data */
   /* on any of the connected sockets. */
   /*************************************************************/
   do{
   //FD_ZERO(&master_set);
   FD_SET(listen_sd,&master_set);

   timeout.tv_sec = 5 * 60;
   timeout.tv_usec = 0;
   /**********************************************************/
   /* Copy the master fd_set over to the working fd_set. */
   /**********************************************************/
   memcpy(&working_set, &master_set, sizeof(master_set));
   /**********************************************************/
   /* Call select() and wait 5 minutes for it to complete. */
   /* success number of file descriptors */
   /* error -1 */
   /*int select(int nfds, fd_set *readfds, fd_set *writefds, */
   /* fd_set *exceptfds, struct timeval *timeout);*/
   /**********************************************************/
   printf("Waiting on select()...\n");
   rc = select(max_sd + 1, &working_set, NULL, NULL, &timeout);
   //printf("rc %d\n",rc);
   /**********************************************************/
   /* Check to see if the select call failed. */
   /**********************************************************/
   if (rc < 0)
   {
   perror(" select() failed");
   break;
   }
   /**********************************************************/
   /* Check to see if the 5 minute time out expired. */
   /**********************************************************/
   if (rc == 0)
   {
   printf(" select() timed out. End program.\n");
   break;
   }
   /**********************************************************/
   /* One or more descriptors are readable. Need to */
   /* determine which ones they are. */
   /**********************************************************/
   desc_ready = rc;
   for (i=0; i <= max_sd && desc_ready > 0; ++i)
   {
   /*******************************************************/
   /* Check to see if this descriptor is ready */
   /*int FD_ISSET(int fd, fd_set *set); */
   /*******************************************************/
   if (FD_ISSET(i, &working_set)){
   /****************************************************/
   /* A descriptor was found that was readable */
   /****************************************************/
   desc_ready -= 1;
   /****************************************************/
   /* Check to see if this is the listening socket */
   /****************************************************/
   if (i == listen_sd){
   printf(" Listening client socket %d is readable\n",i);
   /*************************************************/
   /* Accept all incoming connections */
   /*************************************************/
   /**********************************************/
   /* Accept each incoming connection. */
   /* Success non-negative integer */
   /* error -1 */
   /**********************************************/
   struct sockaddr_in client_addr;
   int addrlen = sizeof(client_addr);
   new_sd = accept(listen_sd, (struct sockaddr*)&client_addr,&addrlen);
   if (new_sd < 0)
   {
   if (errno != EWOULDBLOCK)
   {
   perror(" accept() failed");
   end_server = TRUE;
   }
   break;
   }
   /**********************************************/
   /* Add the new incoming connection */
   /**********************************************/
   printf(" New incoming connection - %d\n", new_sd);

   memset(clist,0,strlen(clist));
   strcpy(clist,"online client id ");

   for(loop = 4;loop < max_sd+2; loop++){
   //send(loop,clist,strlen(clist),0);
   int2str(loop,s);
   strcat(clist,s);
   strcat(clist," ");
   }
   clist[strlen(clist)]='\0';
   //debug
   //printf(" total clist %s\n",clist);
   for(loop_i=4;loop_i < max_sd+2;loop_i++){
   if(send (loop_i,clist,80,0) < 0){
   printf("send error");
   close_conn = TRUE;
   }
   }

   memset(clist,0,strlen(clist));
   strcpy(clist,"welcome to myserver,your client id is ");
   int2str(new_sd,s);
   strcat(clist,s);

   if(send(new_sd,clist,80,0)<0){
   printf("send error");
   close_conn = TRUE;
   }

   FD_SET(new_sd, &master_set);
   if (new_sd > max_sd){
   max_sd = new_sd;
   }
   }
   /****************************************************/
   /* existing connection must be readable */
   /* Receive all incoming data on this socket */
   /****************************************************/
   else{
   memset(buffer,0,strlen(buffer));
   memset(to_mes,0,strlen(to_mes));
   printf(" Descriptor %d is readable\n", i);
   close_conn = FALSE;

   /**********************************************/
   /* Receive data on this connection until the */
   /* recv fails with EWOULDBLOCK. */
   /**********************************************/

   rc = recv(i, buffer, sizeof(buffer), 0);
   if (rc < 0){
   if (errno != EWOULDBLOCK){
   perror(" recv() failed");
   close_conn = TRUE;
   }
   }
   buffer[strlen(buffer)-1]='\0';
   strcpy(temp_buffer,buffer);
   tok=strtok(temp_buffer," ");
   while(tok!=NULL){
   if( !strcmp(tok,"to") && count==0){
   to=1;
   }
   if(to==1 && count==1){
   to_cid=atoi(tok);
   }
   if(to==1 && count>1){
   strcat(to_mes,tok);
   strcat(to_mes," ");
   }
   tok=strtok(NULL," ");
   count++;
   }
   strcpy(temp_buffer,to_mes);
   strcat(temp_buffer," From client ");
   int2str(i,s);
   strcat(temp_buffer,s);
   strcat(temp_buffer," message ");
   temp_buffer[strlen(temp_buffer)-1]='\0';

   if(to==1){
   if(send(to_cid,temp_buffer,80,0)<0){
   printf("send error");
   close_conn = TRUE;
   }
   }
   to=0;
   count=0;
   if (rc == 0){
   printf(" Connection closed\n");
   close_conn = TRUE;
   }

   /**********************************************/
   /* Data was recevied */
   /**********************************************/

   len = rc;
   printf(" server recv: %s\n",buffer);

   //printf(" %d bytes received\n", len);
   /**********************************************/
   /* Echo the data back to the client */
   /**********************************************/

   rc = send(i, buffer, len, 0);

   if (rc < 0){
   perror(" send() failed");
   close_conn = TRUE;
   }
   if (close_conn){
   close(i);
   FD_CLR(i, &master_set);
   if (i == max_sd){
   while (FD_ISSET(max_sd, &master_set) == FALSE){
   max_sd -= 1;
   }
   }
   }

   } /* End of existing connection is readable */
   } /* End of if (FD_ISSET(i, &working_set)) */
   } /* End of loop through selectable descriptors */

   } while (end_server == FALSE);

   /*************************************************************/
   /* Cleanup all of the sockets that are open */
   /*************************************************************/
   for (i=0; i <= max_sd; ++i)
   {
   if (FD_ISSET(i, &master_set))
   close(i);
   }
}

client code

steven@73-245:~/socket/select/test1_add_strtok$ cat client.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <pthread.h>
#include <unistd.h>

void* recv_pthread(void* argument);
void* send_pthread(void* argument);

void error(char *msg)
{
   perror(msg);
   exit(0);
}
int sockfd;
int main(int argc, char *argv[])
{
   int portno,m,on=1;

   struct sockaddr_in serv_addr;
   struct hostent *server;
   char buffer[80],buff[80];
   char* host_name = "192.168.73.247";
   sockfd = socket(PF_INET, SOCK_STREAM,0);
   if (sockfd < 0){
   error("ERROR opening socket");
   }

   m=setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,(char *)&on, sizeof(on));
   if (m < 0){
   perror("setsockopt() failed");
   close(sockfd);
   exit(-1);
   }

   bzero((char *) &serv_addr,sizeof(serv_addr));
   serv_addr.sin_family = PF_INET;
   serv_addr.sin_port = htons(1234);
   serv_addr.sin_addr.s_addr = inet_addr(host_name);

   if (connect(sockfd,(struct sockaddr*)&serv_addr,sizeof(serv_addr)) <0){
   error("ERROR connecting");
   }
   pthread_t recv_id;
   pthread_t send_id;
   if(pthread_create(&recv_id,NULL,recv_pthread,NULL)!=0){
   printf("error creating the recv_thread\n");
   }
   if(pthread_create(&send_id,NULL,send_pthread,NULL)!=0){
   printf("error creating the send_thread\n");
   }
   while(1){
   sleep(1);
   }
   return 0;
}
void* recv_pthread(void* argument){
   int n;
   char buff[80];
   while(1){
   memset(buff,0,strlen(buff));
   n=recv(sockfd,buff,80,0);
   buff[strlen(buff)] = '\0';
   if (n < 0){
   error("ERROR reading from socket");
   }
   printf("recv message : %s\n",buff);
   }
}
void* send_pthread(void* argument){
   int n;
   char buffer[80];
   while(1){
   memset(buffer,0,strlen(buffer));
   printf("\ninput message to server or client : ex: to clientid message\n");
   fgets(buffer,80,stdin);
   n = send(sockfd,buffer,strlen(buffer),0);
   if (n < 0){
   error("ERROR writing to socket");
   }
   }
}
steven@73-245:~/socket/select/test1_add_strtok$

makefile

all:client server
client:client.o
   cc -o client client.o -lpthread
server:server.o
   cc -o server server.o

client.o:client.c
   cc -c client.c

server.o:server.c
   cc -c server.c

clean:
   rm -rf *.o client server

繼續閱讀...

逗點大的雨滴

2011年8月25日星期四

shell script (constructs)

shell script (variable)

signal to open flag

thread of C language

fork of C language

socket and select chart communication

2011年8月25日 星期四