take string input using char in C and C

Question

I'm having trouble accepting a string (actually a character array) as input. 

Consider the following declaration:

char* s;

I have to input a string using this char pointer till i hit "enter", please help! Thanx in advance.

Answer 1

Before beginning to fill it, the s should be assigned.

1) If you do not know the length of the input string in advance, you can use realloc.

char* s = calloc(1,sizeof(char));
char t;
int len;
while(scanf("%c", &t)==1)
{
  if(t== '\n')
     break;
   len = strlen(s);
   s= realloc(s,len+1);
   *(s+len) = t;
   *(s+len+1) = '\0';
}

2) Now, if you know in advance the maximum length of your input string, you may read it directly into a char array with scanf as 

follows:

char s[256] // Let's assume that the max length of your input string is 256

scanf("%[^\r\n]",s) // this will read your input characters till you heat enter even if your string