I'm beginning with c in we were asked to create a small TCP/IP application in C language. In the beginning i was doing just fine, i have tested the server and the client and they were communicating but when i started to develop the main subject of the application which is: a client connect to the server and ask for a book by it's reference. the server it self reads a file which contains lines of some books written as follow(reference;name of the author;title;gender), as you can see in the code i wanted to read the file and store every line in a 2 dimension table.
And then the server compare the reference sent by the client and compare it with what i have in the tables and if it exists, he will send the info of that book to the client.(Sorry, too much phrases but I'm trying to make it clear as possible as i can). therefore when i compile the server and try to execute it, i got a segmentation fault... :(. here is the code. If you could help that would be perfect !.
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <errno.h>
#define MAX_LIGNE 256
/*typedef struct{
int numRef;
char nomAuteur[50];
char titre[50];
char genre[20];
} biblio ;*/
void handler(int sig){
wait(NULL);
}
int main (int argc, char **argv){
struct sigaction ac;
ac.sa_handler = &handler;
ac.sa_flags = SA_RESTART;
char ligne[61];
char *elem=(char *)malloc(sizeof(char)*100);
int i=0;
//biblio tab[30];
char *tab[50][4]={0};
//Stockage des données du fichier dans un tableau
//ouverture du fichier en lecture seule
//char *fichier=";
FILE * fd;
fd=fopen("./fichier-exemple.txt","r");
if(fd==NULL){
printf("Erreur lors de l'ouverture du fichier...\n");
}
//on stock les données du fichier dans la table de structure
while(fgets(ligne,sizeof(ligne),fd)!=NULL){
elem=strtok(ligne,";");
tab[i][0]=(char *)malloc(strlen(elem)*sizeof(char));
strcpy(tab[i][0],elem);
elem=strtok(NULL,";");
tab[i][1]=(char *)malloc(strlen(elem)*sizeof(char));
strcpy(tab[i][1],elem);
elem=strtok(NULL,";");
tab[i][2]=(char *)malloc(strlen(elem)*sizeof(char));
strcpy(tab[i][2],elem);
elem=strtok(NULL,"\n");
tab[i][3]=(char *)malloc(strlen(elem)*sizeof(char));
strcpy(tab[i][3],elem);
i++;
}
free(elem);
fclose(fd);
int longeur=i;
//vérification du nombre d'arguments
if(argc!=2){
fprintf(stderr,"respectez la synthaxe: serveur <port> !\n");
exit(0);
} else {
int port=atoi(argv[1]);
//les structures s et c pour server et client respectivement
struct sockaddr_in s,c;
//création de socket
int p=socket(AF_INET,SOCK_STREAM,0);
if(p<0){
printf("Erreur lors de la création du socket....\n");
exit(0);
}else{
printf("Socket créé avec succès....\n");
}
//remplissage de la structure s
s.sin_family=AF_INET;
s.sin_addr.s_addr=htonl(INADDR_ANY);
s.sin_port=htons(port);
socklen_t Slen= (socklen_t)sizeof(c);
//création de bind
int b= bind(p,(const struct sockaddr *)&s, Slen);
if(b<0){
printf("Erreur lors du bind...\n");
exit(0);
}else{
printf("Bind créé avec succès...\n");
}
//l'écoute
int l= listen(p,20);
if(l==-1){
printf("Erreur d'écoute ...\n");
exit(0);
}else{
printf("En écoute...\n");
}
//boucle infini pour accepter les demandes des clients
while(1){
int acpt=accept(p,(struct sockaddr *) &c, &Slen);
if(acpt==-1){
printf("Erreur d'acceptation...\n");
}else{
printf("Acceptation...\n");
}
int f=fork();
if(f==0){
char * res=(char *)calloc(MAX_LIGNE,sizeof(char));
char * buffer=(char *)calloc(MAX_LIGNE,sizeof(char));
while(1){
//réception du trajet depuis le client
//recv(acpt,buffer,MAX_LIGNE,0);
recv(acpt, &buffer, strlen(buffer),0);
int buf=atoi(buffer);
//char ligne[50];
int j=0;
for(j=0;j<longeur;j++){
//printf("%s",tab[j].genre);
if(atoi(tab[j][0])==buf){
strcpy(res,tab[j][1]);
strcat(res, ", ");
strcat(res,tab[j][2]);
strcat(res, ", ");
strcat(res,tab[j][3]);
strcat(res,"\n");
}
}
send(acpt,&res,strlen(res),0);
}
free(buffer);
free(res);
}else{
sigaction(SIGCHLD,&ac,NULL);
}
}
}
}
