C++ question...

cbjhawks · 11-19-2003, 07:39 AM

How do I append one string to another "without" using concatenate in the source code?...thanks for your reply

LogicG8 · 11-19-2003, 09:37 AM

rewrite the concatenate function

Code:

/*
* This doesn't do any checks, so make damn sure everything
* fits into the destination string before-hand...
*/
char *noconcat(char *dest, char *src)
{
	int len;
	char *start;
	
	len = strlen(dest);
	start = dest + len;
	strcpy(start, src);
	return dest;
}

worldmagic · 11-19-2003, 09:44 AM

So whats diffrent with that code compared to the libc: strcat ? ..

$man strcat

NAME
strcat, strncat - concatenate two strings

SYNOPSIS
#include <string.h>

char *strcat(char *dest, const char *src);

DESCRIPTION
The strcat() function appends the src string to the dest string over-
writing the `\0' character at the end of dest, and then adds a termi-
nating `\0' character. The strings may not overlap, and the dest
string must have enough space for the result.

LogicG8 · 11-19-2003, 09:53 AM

worldmagic:
If I wrote it correctly nothing.
I didn't look at the source for glibc so
I can't give a line by line comparison.

I figured cbjhawks is stumped on a hw
question. Otherwise his question doesn't
make much sense. If he's not looking to
avoid the string library function his question
breaks down into "How do I do this without
doing it?" and while he might be looking
for overloaded operators for the String class
he's still going to have to code it someplace.

worldmagic · 11-19-2003, 10:21 AM

Hehe, yeaps your code should be the same as the glibc (havent checked tho).. I guess his realy thinking of the overhead of creating new String objects. Cbjhawks please clearyfy your question =) .. If you thinking of how to avoid extra allocations, strcat from libc might work, if you try to avoid some HW/SW problem using your libc implementation use the suggested code from LogicG8