From 204194cdc414df177f49372783b604c8d43763da Mon Sep 17 00:00:00 2001 From: Jim Warner Date: Tue, 15 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 082710d2..a41755c4 100644 --- a/top/top.h +++ b/top/top.h @@ -509,7 +509,7 @@ 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))