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authorJes Sorensen <Jes.Sorensen@redhat.com>2010-10-21 17:15:46 +0200
committerAnthony Liguori <aliguori@us.ibm.com>2010-11-03 12:48:09 -0500
commit9f9b17a4f0865286391e4d3a0a735230122a2289 (patch)
treed80f635564a4130868aba2065e36729901c766d0 /cutils.c
parent7d72e76228351d18a856f1e4f5365b59d3205dc3 (diff)
Introduce strtosz() library function to convert a string to a byte count.
strtosz() returns -1 on error. It now supports human unit formats in eg. 1.0G, with better error handling. The following suffixes are supported: B/b = bytes K/k = KB M/m = MB G/g = GB T/t = TB This patch changes -numa and -m input to use strtosz(). Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Diffstat (limited to 'cutils.c')
-rw-r--r--cutils.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/cutils.c b/cutils.c
index 588373774a..28089aa3e4 100644
--- a/cutils.c
+++ b/cutils.c
@@ -23,6 +23,7 @@
*/
#include "qemu-common.h"
#include "host-utils.h"
+#include <math.h>
void pstrcpy(char *buf, int buf_size, const char *str)
{
@@ -283,3 +284,90 @@ int fcntl_setfl(int fd, int flag)
}
#endif
+/*
+ * Convert string to bytes, allowing either B/b for bytes, K/k for KB,
+ * M/m for MB, G/g for GB or T/t for TB. Default without any postfix
+ * is MB. End pointer will be returned in *end, if not NULL. A valid
+ * value must be terminated by whitespace, ',' or '\0'. Return -1 on
+ * error.
+ */
+ssize_t strtosz(const char *nptr, char **end)
+{
+ ssize_t retval = -1;
+ char *endptr, c;
+ int mul_required = 0;
+ double val, mul, integral, fraction;
+
+ errno = 0;
+ val = strtod(nptr, &endptr);
+ if (isnan(val) || endptr == nptr || errno != 0) {
+ goto fail;
+ }
+ integral = modf(val, &fraction);
+ if (integral != 0) {
+ mul_required = 1;
+ }
+ /*
+ * Any whitespace character is fine for terminating the number,
+ * in addition we accept ',' to handle strings where the size is
+ * part of a multi token argument.
+ */
+ c = *endptr;
+ if (isspace(c) || c == '\0' || c == ',') {
+ c = 0;
+ }
+ switch (c) {
+ case 'B':
+ case 'b':
+ mul = 1;
+ if (mul_required) {
+ goto fail;
+ }
+ break;
+ case 'K':
+ case 'k':
+ mul = 1 << 10;
+ break;
+ case 0:
+ if (mul_required) {
+ goto fail;
+ }
+ case 'M':
+ case 'm':
+ mul = 1ULL << 20;
+ break;
+ case 'G':
+ case 'g':
+ mul = 1ULL << 30;
+ break;
+ case 'T':
+ case 't':
+ mul = 1ULL << 40;
+ break;
+ default:
+ goto fail;
+ }
+ /*
+ * If not terminated by whitespace, ',', or \0, increment endptr
+ * to point to next character, then check that we are terminated
+ * by an appropriate separating character, ie. whitespace, ',', or
+ * \0. If not, we are seeing trailing garbage, thus fail.
+ */
+ if (c != 0) {
+ endptr++;
+ if (!isspace(*endptr) && *endptr != ',' && *endptr != 0) {
+ goto fail;
+ }
+ }
+ if ((val * mul >= ~(size_t)0) || val < 0) {
+ goto fail;
+ }
+ retval = val * mul;
+
+fail:
+ if (end) {
+ *end = endptr;
+ }
+
+ return retval;
+}