From 98ca9fe3676fbc479a02005fe45b0cb019e277d7 Mon Sep 17 00:00:00 2001 From: Jim Warner Date: Mon, 14 Feb 2022 00:00:00 -0600 Subject: [PATCH] top: trade that 'strncpy' for more efficient 'memccpy' This patch was prompted by the merge request for pgrep referenced below. In top's case, any performance gains will be minimal since the now defunct strncpy was only employed for termcap rebuilds after interacting with a user (+ 1 other non-termcap related user interaction). [ golly, strncpy always calls at least two functions ] [ but usually calls a total of 3. on the other hand, ] [ memccpy will only call a maximum of two functions. ] And thanks to Baruch Siach for these strncpy insights. Reference(s): https://gitlab.com/procps-ng/procps/-/merge_requests/148 Signed-off-by: Jim Warner --- top/top.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/top/top.h b/top/top.h index 28ae2310..3e67e493 100644 --- a/top/top.h +++ b/top/top.h @@ -435,7 +435,7 @@ typedef struct WIN_t { /* A null-terminating strncpy, assuming strlcpy is not available. ( and assuming callers don't need the string length returned ) */ -#define STRLCPY(dst,src) { strncpy(dst, src, sizeof(dst)); dst[sizeof(dst) - 1] = '\0'; } +#define STRLCPY(dst,src) { memccpy(dst, src, '\0', sizeof(dst)); dst[sizeof(dst) - 1] = '\0'; } /* Used to clear all or part of our Pseudo_screen */ #define PSU_CLREOS(y) memset(&Pseudo_screen[ROWMAXSIZ*y], '\0', Pseudo_size-(ROWMAXSIZ*y))