From fd193829744bc77392395cf8f47889235c97f0a3 Mon Sep 17 00:00:00 2001 From: "Robert P. J. Day" Date: Fri, 25 Jul 2008 01:45:31 -0700 Subject: [PATCH] lib: allow memparse() to accept a NULL and ignorable second parm Extend memparse() to allow the caller to use a NULL second parameter, which would represent no interest in returning the address of the end of the parsed string. In numerous cases, callers invoke memparse() to parse a possibly-suffixed string (such as "64K" or "2G" or whatever) and define a character pointer to accept the end pointer being returned by memparse() even though they have no interest in it and promptly throw it away. This (backward-compatible) enhancement allows callers to use NULL in the cases where they just don't care about getting back that end pointer. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Robert P. J. Day Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/cmdline.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/lib/cmdline.c b/lib/cmdline.c index f596c08d213a..5ba8a942a478 100644 --- a/lib/cmdline.c +++ b/lib/cmdline.c @@ -116,7 +116,7 @@ char *get_options(const char *str, int nints, int *ints) /** * memparse - parse a string with mem suffixes into a number * @ptr: Where parse begins - * @retptr: (output) Pointer to next char after parse completes + * @retptr: (output) Optional pointer to next char after parse completes * * Parses a string into a number. The number stored at @ptr is * potentially suffixed with %K (for kilobytes, or 1024 bytes), @@ -126,11 +126,13 @@ char *get_options(const char *str, int nints, int *ints) * megabyte, or one gigabyte, respectively. */ -unsigned long long memparse (char *ptr, char **retptr) +unsigned long long memparse(char *ptr, char **retptr) { - unsigned long long ret = simple_strtoull (ptr, retptr, 0); + char *endptr; /* local pointer to end of parsed string */ - switch (**retptr) { + unsigned long long ret = simple_strtoull(ptr, &endptr, 0); + + switch (*endptr) { case 'G': case 'g': ret <<= 10; @@ -140,10 +142,14 @@ unsigned long long memparse (char *ptr, char **retptr) case 'K': case 'k': ret <<= 10; - (*retptr)++; + endptr++; default: break; } + + if (retptr) + *retptr = endptr; + return ret; }