Thread: SegFault Help!

I give the input and when i press enter i get a segfault! can you help me?
thanks

Code:

#include <stdio.h>
#include <ctype.h>
#define N 100
#define M 37
#define AEM_MAX 4

int main (int argc, char *argv[]) {
    
    char studentdata[N][M], c;
    int i, pos;
    
    

    for (i=0;i<N;i++) {
        fgets(studentdata[i],M,stdin);
        if (studentdata[i][0]=='-') {
            break;
        }
        else {
            do {
                c=getchar();  /*Aporofhsh tou kenou*/
            } while (c!='\n');
        }
        }
    
    for (i=0;i<N;i++) {
        studentdata[i][31]='\0';  /*antikatastash tou ' ' me to \0 */
    }
    
    for (i=0;i<N-5;i++) { /*Bazw -5 giati den thelw na exw thn telia ston elegxo*/
        if (ispunct(studentdata[i])) {
            pos=i;
        }
    }
    printf("%s. ",studentdata[pos+1]); /*Ektypwsh tou prwtou grammatos tou onomatos*/
    for (i=0;i<pos;i++) {
        if (isalpha(studentdata[i])) {
            printf("%s",studentdata[i]);
        }
    }
    printf(" ");
    for (i=0;i<AEM_MAX;i++) {                 /*Dhlwsa to AEM_MAX ws 4 dioti to AEM einai to polu 5 arithmoi*/
        if (isdigit(studentdata)) {            /*opote mou arkei o elegxos apo to stoixeio 0 ews to stoixeio 4*/
            printf("%s",studentdata[i]);
        }
    }
    printf(" ");
    
        
   
    
                 






    return(0);
}

My first suggestion would be that you use meaningful variable names. For example instead of N use something like NUMBER_OF_STUDENTS and instead of M use something like NAME_LENGTH. It looks like you may have switched M and N is several of your loops, so maybe using meaningful names may help insure you're using the correct sizes for each loop.

You also are using several magic numbers (5, 31) you may want to create meaningful named constants for these values as well.

Also without knowing what you're inputting into the program it is hard to go much farther.

Jim

Thanks for the comments, i will try to improve my programm(second month learning C programming).
So its better to use strchr to check for dots and etc?