lua_pushfstring

lua_pushfstring[-0, +1, e]

const char *lua_pushfstring (lua_State *L, const char *fmt, ...);

Pushes onto the stack a formatted string and returns a pointer to this string. It is similar to the ISO C function sprintf, but has some important differences:

• You do not have to allocate space for the result: the result is a Lua string and Lua takes care of memory allocation (and deallocation, through garbage collection).
• The conversion specifiers are quite restricted. There are no flags, widths, or precisions. The conversion specifiers can only be '%%' (inserts the character '%'), '%s' (inserts a zero-terminated string, with no size restrictions), '%f' (inserts a lua_Number), '%I' (inserts a lua_Integer), '%p' (inserts a pointer as a hexadecimal numeral), '%d' (inserts an int), '%c' (inserts an int as a one-byte character), and '%U' (inserts a long int as a UTF-8 byte sequence).

Unlike other push functions, this function checks for the stack space it needs, including the slot for its result.