Node:Dynamic Output, Next:Variable Arguments Output, Previous:Formatted Output Functions, Up:Formatted Output
The functions in this section do formatted output and place the results in dynamically allocated memory.
int asprintf (char **ptr, const char *template, ...) | Function |
This function is similar to sprintf , except that it dynamically
allocates a string (as with malloc ; see Unconstrained Allocation) to hold the output, instead of putting the output in a
buffer you allocate in advance. The ptr argument should be the
address of a char * object, and asprintf stores a pointer
to the newly allocated string at that location.
The return value is the number of characters allocated for the buffer, or less than zero if an error occurred. Usually this means that the buffer could not be allocated. Here is how to use /* Construct a message describing the value of a variable whose name is name and whose value is value. */ char * make_message (char *name, char *value) { char *result; if (asprintf (&result, "value of %s is %s", name, value) < 0) return NULL; return result; } |
int obstack_printf (struct obstack *obstack, const char *template, ...) | Function |
This function is similar to asprintf , except that it uses the
obstack obstack to allocate the space. See Obstacks.
The characters are written onto the end of the current object.
To get at them, you must finish the object with |