[libvirt] [PATCH 1/2] util: implement virStrToDoubleSafe().

[Julio Faracco]

Following the GNU Documentation, functions to convert double/float to string
and vice versa, use the locale to set the mantissa separator. Some languages
use comma and other use dot as a separator.

For example: 1,212.67 (en_US) = 1.112,67 (pt_BR).

This can be used to parse values in float/double from XML and other definition
files.

Signed-off-by: Julio Faracco <jcfaracco at gmail.com>
---
 src/libvirt_private.syms |  1 +
 src/util/virstring.c     | 31 +++++++++++++++++++++++++++++++
 src/util/virstring.h     |  4 ++++
 3 files changed, 36 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 044510f..9d791e6 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2659,6 +2659,7 @@ virStringTrimOptionalNewline;
 virStrncpy;
 virStrndup;
 virStrToDouble;
+virStrToDoubleSafe;
 virStrToLong_i;
 virStrToLong_l;
 virStrToLong_ll;
diff --git a/src/util/virstring.c b/src/util/virstring.c
index 089b539..6dad00f 100644
--- a/src/util/virstring.c
+++ b/src/util/virstring.c
@@ -537,6 +537,37 @@ virStrToDouble(char const *s,
 }
 
 int
+virStrToDoubleSafe(char const *s,
+                   char **end_ptr,
+                   double *result)
+{
+    char *cur_locale = NULL;
+    char *saved_locale = NULL;
+    int ret = -1;
+
+    cur_locale = setlocale (LC_ALL, NULL);
+    if (!cur_locale)
+        return ret;
+
+    if (VIR_STRDUP(saved_locale, cur_locale) < 0)
+        goto cleanup;
+
+    if (!setlocale (LC_ALL, "C"))
+        goto cleanup;
+
+    ret = virStrToDouble(s, end_ptr, result);
+
+    // Cannot restore the locale.
+    if (!setlocale (LC_ALL, saved_locale))
+        ret = -1;
+
+ cleanup:
+    VIR_FREE(saved_locale);
+    VIR_FREE(cur_locale);
+    return ret;
+}
+
+int
 virVasprintfInternal(bool report,
                      int domcode,
                      const char *filename,
diff --git a/src/util/virstring.h b/src/util/virstring.h
index 0038a40..fa551b7 100644
--- a/src/util/virstring.h
+++ b/src/util/virstring.h
@@ -108,6 +108,10 @@ int virStrToDouble(char const *s,
                    char **end_ptr,
                    double *result)
     ATTRIBUTE_RETURN_CHECK;
+int virStrToDoubleSafe(char const *s,
+                       char **end_ptr,
+                       double *result)
+    ATTRIBUTE_RETURN_CHECK;
 
 void virSkipSpaces(const char **str) ATTRIBUTE_NONNULL(1);
 void virSkipSpacesAndBackslash(const char **str) ATTRIBUTE_NONNULL(1);
-- 
2.7.4