check_snmp: Update last patch to copy value verbatim

Rework last patch, copying the converted portion of the string rather
than re-converting it. This is safer for backwards-compatibility as the
value is never modified.

1 files changed, 6 insertions, 10 deletions

diff --git a/plugins/check_snmp.c b/plugins/check_snmp.c
index ce3919d..fdb5819 100644
--- a/plugins/check_snmp.c
+++ b/plugins/check_snmp.c
@@ -117,12 +117,11 @@ int needmibs = FALSE;
 int
 main (int argc, char **argv)
 {
-        int i;
+        int i, len;
         int iresult = STATE_UNKNOWN;
         int result = STATE_UNKNOWN;
         int return_code = 0;
         int external_error = 0;
-        double perftmp;
         char **command_line = NULL;
         char *cl_hidden_auth = NULL;
         char *oidname = NULL;
@@ -352,17 +351,14 @@ main (int argc, char **argv)
                 if (nunits > (size_t)0 && (size_t)i < nunits && unitv[i] != NULL)
                         asprintf (&outbuff, "%s %s", outbuff, unitv[i]);
 
-                /* Try a two-way conversion of show and add perfdata only if we get
-                 * something back at the end */
+                /* Write perfdata with whatever can be parsed by strtod, if possible */
                 ptr = NULL;
-                perftmp = strtod(show, &ptr);
-                if (ptr != show) {
-                        ptr = NULL;
-                        asprintf(&ptr, "%0.9g", perftmp);
+                strtod(show, &ptr);
+                if (ptr > show) {
                         strncat(perfstr, oidname, sizeof(perfstr)-strlen(perfstr)-1);
                         strncat(perfstr, "=", sizeof(perfstr)-strlen(perfstr)-1);
-                        strncat(perfstr, ptr, sizeof(perfstr)-strlen(perfstr)-1);
-                        free(ptr);
+                        len = sizeof(perfstr)-strlen(perfstr)-1;
+                        strncat(perfstr, show, len>ptr-show ? ptr-show : len);
 
                         if (type)
                                 strncat(perfstr, type, sizeof(perfstr)-strlen(perfstr)-1);