3 replies to this topic

[fazla]

Hi!I'm new to C programming and I wanted to ask where is the error in this code:
I have a file text ( frase.txt),placed in the same folder and I have to search for a string in this text and if I find that string I have to print it.


Code:

#include <stdlib.h>
#include <stdio.h>
#include <string.h>


int main(){
const char searchingString[20];
FILE *fillle= fopen("frase","r");

char *s;
char *token;
printf("Introduce the string:");
scanf("%s",searchingString);

while(fgets(s,128,fillle)!=NULL){

token = strtok(s ," ");

if(strcmp(token,searchingString) == 0)
printf("%s\n",searchingString);
else printf("0\n");
while (strtok!=NULL) {
token= strtok(NULL," ");
if(strcmp(token,searchingString) == 0)
printf("%s\n",searchingString);
else printf("0\n");
}
}
}

When I compile the file it doesn't give me any problem and when I try the program it prints on the monitor Introduce the string,but when I give it it says segmentation fault!
What's the problem?thanks!

Sorry for my English!

[JCoder]

The error is here: const char searchingString[20]
Remove the const.

BTW: never, ever use scanf for reading data into buffers. Use fgets.

[Ancient Dragon]

>>while (strtok!=NULL) {

That is testing to see if a function address is NULL :w00t: I think you meant while( token != NULL ) {

[fazla]

JCoder said:

The error is here: const char searchingString[20]
Remove the const.

BTW: never, ever use scanf for reading data into buffers. Use fgets.

Why this?

Anyway I've removed the const and this is my new code but it stills give me the same problem:

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

int main(){
char searchingString[20];
FILE *fillle= fopen("frase","r");
char s[512];
char *token;
printf("Introduci la stringa da cercare:");
scanf("%s",searchingString);
while(fgets(s,512,fillle)!=NULL){
token = strtok(s ," ");
if(strcmp(token,searchingString) == 0)
printf("%s\n",searchingString);
else printf("0\n");
while (strtok!=NULL) {
token= strtok(NULL," ");
if(strcmp(token,searchingString) == 0)
printf("%s\n",searchingString);
else printf("0\n");
}
}
}