Keeping leading spaces in C [closed] - c

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I'm having this simple problem that I can't get over with.
int B;
char *a = (char*)malloc(1000*sizeof(char);
scanf("%[^\n]s", a);
printf("%c\n", a[0]);
B = strlen(a);
printf("%d\n", B);
If I put an entry like:
" abc "
a[0] = 'a' and B = 5 (the "abc" plus the last two spaces). I want to count the first three spaces, how do I do it?

Answer 1

You could simply read the entire line using fgets() instead of using scanf(), which generally skips whitespace unless you explicitly capture it.
int B;
char *a = malloc(1000 * sizeof*a); /* don't cast malloc */
if (fgets(a, 1000, stdin) == NULL) {
fputs("Could not read input\n", stdout);
}
else {
printf("%c\n", a[0]);
B = strlen(a);
printf("%d\n", B);
}

Answer 2

If you want to trim the leading space, you can try this:
void trim_left(char *p);
int main()
{
int B;
char *a = (char*)malloc(1000*sizeof(char));
scanf("%[^\n]s", a);
printf("%c\n", a[0]);
trim_left(a);
B = strlen(a);
printf("%d\n", B);
printf("a = %s\n", a);
return 0;
}
void trim_left(char *p) {
int i = 0;
while (p[i] && isspace(p[i])) {
i++;
}
memmove(p, p+i, strlen(p+i));
p[strlen(p+i)] = '\0';
}