I'm implementing a program of communication by sending and receiving data between a server and a client:
I have a problem when writing data to a file and multiply it by 3.0. The program is only doing it for the first number stored in the file.
This is because when reading numbers from a file input.asc the program is read as a single message, and should read number by number and send to the server.
The file input.asc can have any number for example:
1.0
2.0
3.0
How to change this part of the code to read number by number to the message (msg.buffer)?
The part of the code to change itś brown.
Client:
Code:#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/msg.h> #include <string.h> #include <ctype.h> #include <fcntl.h> #define SERVER 1L typedef struct { long msg_to; long msg_fm; char buffer[BUFSIZ]; } MESSAGE; int mid; key_t key; struct msqid_ds buf; MESSAGE msg; FILE *inFile; int main(int argc, char** argv) { //Aquiring Message Queue ID key = ftok(".", 'z'); mid = msgget(key, 0); //Display Message Queue and Client ID printf("Message Queue ID: %d\n", mid); printf("Client ID: %ld\n", (long)getpid()); //Opening input file, throw an error if invalid file inFile = fopen("input.asc", "r"); if(inFile == NULL){ printf("Unable to open File = input.asc"); return 1; } //Copy input into msg.buffer, loops breaks when EOF is reached int i = 0; while(1){ msg.buffer[i] = fgetc(inFile); if(msg.buffer[i]==EOF){ msg.buffer[i] = '\0'; break; } i++; } //Displaying message before conversion of server printf("Message before conversion:\n"); printf("%s\n", msg.buffer); //Getting Client PID and preparing message to message queue long iD = (long)getpid(); msg.msg_to = SERVER; msg.msg_fm = (long)getpid(); //Send message to Message Queue for Server, throws and error for invalid input if(msgsnd(mid, &msg, sizeof(msg.buffer), 0)==-1){ perror("msgsnd"); exit(-1); } //Client waits for response from Server, throws an error if invalid input if(msgrcv(mid, &msg, sizeof(msg), iD, 0)<0){ perror("msgrcv"); exit(-1); } //Display new converting message. printf("Message after conversion\n"); printf("%s\n", msg.buffer); //Removing message queue msgctl(mid, IPC_RMID, (struct msqid_ds *) 0); //Client exits return (EXIT_SUCCESS); }
Server:
Code:#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/ipc.h> #include <sys/msg.h> #include <string.h> #include <ctype.h> #include <fcntl.h> #define SERVER 1L typedef struct { long msg_to; long msg_fm; char buffer[BUFSIZ]; } MESSAGE; int mid; key_t key; struct msqid_ds buf; MESSAGE msg; int inbin; FILE *bin; FILE *outasc; int conta = 0; int main(int argc, char** argv) { //Creating a message queue key = ftok(".", 'z'); if((mid = msgget(key, IPC_CREAT | 0660))<0){ printf("Error Creating Message Queue\n"); exit(-1); } //Display Message Queue and Server ID printf("Message Queue ID: %d\n", mid); printf("Server ID: %ld\n", (long)getpid()); //Receiving message from client, throws and error if input is invalid if(msgrcv(mid, &msg, sizeof(msg.buffer), SERVER, 0)<0){ perror("msgrcv"); exit(-1); } //Aquiring Cliend PID to message return long client = msg.msg_fm; //Server displays received message printf("SERVER receives:\n"); printf("%s\n", msg.buffer); float aux=atof(msg.buffer); printf("Conversion:%lf\n", aux); //Creating the file input.bin if((inbin = open("input.bin",O_WRONLY|O_TRUNC|O_CREAT,0600)) < 0) { perror("\nERROR NO input.bin!\n"); exit(1); } else { printf("\n File input.bin read\n"); printf("-------------------------\n\n"); int i=0; while(msg.buffer[i] != '\0'){ write(inbin,&aux,sizeof(float)); i++; conta++; } } //Close the file input.bin int closeinbin = close(inbin); if(closeinbin < 0) { perror("\nERROR close the file input.bin\n"); exit(1); } float tab[conta]; //Open input.bin and saved the data int readinbin = fread(&tab,sizeof(tab),1,(bin=fopen("input.bin","r"))); if(bin < 0 || readinbin < 0) { perror("\n ERROR open the file input.bin\n"); exit(1); } //Close the file input.bin if(fclose(bin) < 0) { perror("\nERROR close the file input.bin!\n"); exit(1); } //Criar o output.asc// if((outasc=fopen("output.asc","a")) < 0) { perror("ERROR open the file output.asc"); exit(1); } //Write in file output.asc// int a; for(a = 0; a < conta; a++) { char BUFFER[20]; tab[a] = 3.0*tab[a]; sprintf(BUFFER,"%f",tab[a]); fputs(BUFFER,outasc); fputs("\n",outasc); printf("Wrote: %f \n",tab[a]); } if(fclose(outasc) < 0) { printf("ERROR close the file"); exit(1); } //prep return message msg.msg_fm = SERVER; msg.msg_to = client; //send converting message back to client, throws and error if input is invalid if(msgsnd(mid, (struct MESSAGE*)&msg, sizeof(msg.buffer), 0)==-1){ perror("msgsnd"); exit(-1); } //server exits return (EXIT_SUCCESS); }
