How do I read and store string of arbitrary length using malloc and realloc in C?

Question

I have a structure

typedef struct store
{
   char name[11];
    int age;
} store;

and a main function(below is part of it):

int         


        

Answer 1

This alternative approach is similar to @asveikau's, but economize on the use of malloc() by copying on the stack.

Please do not use this for homework answer.

#include 
#include 
#include 
char * slurponeline(FILE *f, int s) {
 const int size = 4096;
 char buffer[size];
 char * r;
 int c,i=0;
 while( i=0 && c!='\n')) buffer[i++]=c;
 if (0 == s && 0 == i) return 0;
 r = (size==i)? slurponeline(f,s+size):malloc(s+i);
 memcpy(r+s,buffer,i);
 return r;
}
int main(int argc, char ** argv) {
 FILE * f = fopen(argc>1?argv[1]:"a.out","rb");
 char * a,*command,*commandend,*name,*nameend;
 int age;
 while (a = slurponeline(f,0)) {
  char * p = a;
  while (*p && *p == ' ') ++p; // skip blanks.
  command = p;
  while (*p && *p != ' ') ++p; // skip non-blanks.
  commandend = p;
  while (*p && *p == ' ') ++p; // skip blanks.
  name = p;
  while (*p && *p != ' ') ++p; // skip non-blanks.
  nameend = p;
  while (*p && *p == ' ') ++p; // skip blanks.
  age = atoi(p);
  *commandend=0;
  *nameend=0;
  printf("command: %s, name: %s, age: %d\n",command,name,age);
  free(a);
 }
}