lib: allow memparse() to accept a NULL and ignorable second parm (fd193829) · Commits · 戴 / test

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 <rpjday@crashcourse.ca> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

lib/cmdline.c

+11 −5

Original line number	Diff line number	Diff line
		@@ -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),
		@@ -128,9 +128,11 @@ char get_options(const char str, int nints, int *ints)

		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;
		}

Admin message