I want to create a "fullname" variable from multiple strings. Something like this:
strcpy (fullname, firstname);
strcat (fullname, separator); // separator is initialized at " "
strcat (fullname, middlename);
strcat (fullname, separator);
strcat (fullname, lastname);
This code is repeated at multiple places in my project. I was gonna do a function that does exactly that, but now I wonder if there isn't a better way to do it.
Any ideas?
You can do also:
sprintf (fullname, "%s%s%s%s%s", firstname, separator, middlename, separator, lastname);
But always make sure that the fullname points to a buffer which can accommodate the total length of all the things you are concatenating.
int size;
int *fullname;
size = strlen (firstname) + strlen (separator) + strlen (middlename) + strlen (separator) + strlen (lastname) + 1;
fullname = malloc (sizeof (char) * size);
sprintf (fullname, "%s%s%s%s%s", firstname, separator, middlename, separator, lastname);
/* Work */
free (fullname);
sprintf(fullname, "%s%s%s%s%s", firstname, separator, middlename, separator, lastname);
If separator is always " " then you can do
sprintf(fullname, "%s %s %s", firstname, middlename, lastname);
Though you need to ensure that fullname has sufficient space.
There's stpcpy (became standard in posix 2008). It'd look like this:
char *ptr = fullname:
ptr = stpcpy (ptr, firstname);
ptr = stpcpy (ptr, separator);
ptr = stpcpy (ptr, middlename);
ptr = stpcpy (ptr, separator);
ptr = stpcpy (ptr, lastname);
If you also need to take care not to overflow fullname, use stpncpy instead:
char *ptr = fullname;
char *end = fullname + sizeof(fullname) - 1;
ptr = stpncpy (ptr, firstname, end - ptr);
ptr = stpncpy (ptr, separator, end - ptr);
ptr = stpncpy (ptr, middlename, end - ptr);
ptr = stpncpy (ptr, separator, end - ptr);
ptr = stpncpy (ptr, lastname, end - ptr);
*ptr = '\0'; // Or optionally error if ptr >= end
snprintf can also be a good choice:
snprintf(fullname, sizeof(fullname), "%s%s%s%s%s", firstname, separator, middlename, separator, lastname);
