string - Issue with printing char *argv[n] after a function call in C -

int readoptions(char *argv[]){         file * infile;         char line_buf[bufsiz];         int = 0, j = 0 ;          infile = fopen("options","r");             if(!infile){                       fprintf(stderr,"file read failure\n");                         exit(2);             }          while( < 10 && fgets(line_buf,sizeof(line_buf),infile)!=0){               printf("line buf : %s",line_buf);               argv[i] =  line_buf;                                                  i++;                                }  }  int main(){  int j ;   char *options[10];   for(j = 0 ; j< 10 ; j++){          options[j] = malloc(len * sizeof (char));     }    readoptions(options); for(j=0; j<10 ; j++)          printf("%s %d\n",options[j], j );  } 

the problem see - program print last line read in file. mistake ? , missing important pointer concept code ?

every element of argv points same line_buf. use strdup() create new strings instead (which later have free).