[C언어] 내장함수 비교 - strlcpy, strlcat

앞서 <string.h>의 strcpy, strncpy, strlcpy의 차이를 정리했다.

그 중 strlcpy는 strlcat과 유사하다. 실제로 man 가이드는 이 둘을 같이 안내한다.

간단히 차이점을 정리해본다. 

 

 

strlcpy

PROTOTYPE	#include <string.h> size_t strlcpy(char *restrict dst, const char *restrict src, size_t dstsize);
DESCRIPTION	- strlcpy() takes the full size of the destination buffer - strlcpy() copies up to dstsize - 1 characters from the string src to dst, NUL-terminating the result if dstsize is not 0. - It is designed to be safer, more consistent, and less error prone replacements for the easilymisused functions strncpy().
RETURN	the length of src : the total length of the string they tried to create.
CONSIDERATIONS	- strlcpy() guarantees NUL-termination if there is room.    Note that room for the NUL should be included in dstsize.  - If return value is >= dstsize, output string has been truncated.

 

 

strlcat

PROTOTYPE	#include <string.h> size_t strlcat(char *restrict dst, const char *restrict src, size_t dstsize);
DESCRIPTION	- strlcat() takes the full size of the destination buffer. - strlcat() appends string src to the end of dst. It will append at most dstsize - strlen(dst) - 1 characters. - It will then NUL-terminate, unless dstsize is 0 or the original dst string was longer than dstsize (in practice this should not happen as it means that either dstsize is incorrect or that dst is not a proper string). - It is designed to be safer, more consistent, and less error prone replacements for the easilymisused functions strncat().
RETURN	- the initial length of dst + the length of src : the total length of the string they tried to create. - the length of src : if dstsize == 0  - the parameter dstsize + the length of src : if dstsize <= the initial length of dst
CONSIDERATIONS	- strlcat() guarantees NUL-termination if there is room.    Note that room for the NUL should be included in dstsize.  - If return value is >= dstsize, output string has been truncated.

 

 

strlcpy와 strlcat 비교

PROTOTYPE	size_t strlcpy(char *restrict dst, const char *restrict src, size_t dstsize);	size_t strlcat(char *restrict dst, const char *restrict src, size_t dstsize);
NAME	size-bounded string copying and concatenation
DESCRIPTION	copies and concatenate strings with the same input parameters and output result as snprintf().
	- replacements for the easilymisused functions strncpy().	- replacements for the easilymisused functions strncat().
PARAMETER & BEHAVIOR	takes the full size of the destination buffer.
	copies up to dstsize - 1 characters from the string src to dst, NUL-terminating the result if dstsize is not 0.	appends string src to the end of dst. It will append at most dstsize - strlen(dst) - 1 characters.
	If return value is >= dstsize, output string has been truncated.
RETURN	the length of src	- the initial length of dst plus the length of src - the length of src - the parameter dstsize + the length of src
NUL Assurance	guarantees NUL-termination if there is room. room for the NUL should be included in dstsize