Append Char To String in C?

Question

How do I append a single char to a string in C?

i.e

char* str = "blablabla";
char c = 'H';
str_append(str,c); /* blablablaH */

Answer 1

char* str = "blablabla";     

You should not modify this string at all. It resides in implementation defined read only region. Modifying it causes Undefined Behavior.

You need a char array not a string literal.

Good Read:
What is the difference between char a[] = "string"; and char *p = "string";