[Nagiosplug-devel] Patch for popen.c and check_snmp.c allowing environment to be pas sed

[Karl Ewald]

Hi developers,

We have found the need to pass an environment variable to the process called
by check_snmp (snmpget). In the particular case, this may well be attributed
to my stupidity while building ucd-snmp, however I can foresee valid reasons
for wanting to pass an environment to a called program. The following patch
permits doing this.

One could also choose to pass the environment inherited, which would be
somewhat more natural, but it was actually beneficial to us to ensure a
well-defined state when executing the external program. The definition of
CHILD_ENV_ARRAY would probably be better placed in the Makefile, however I
didn't want to touch too many files to keep the change tightly contained. My
setting can only serve as an example.

1.1 is my own version number for each file as distributed with
netsaint-plugins-1.2.9-4

I hope it is of some use to you.

============================================================================
========
diff -u -r1.1 popen.c
--- popen.c     2002/06/19 17:20:31     1.1
+++ popen.c     2002/06/19 18:40:23
@@ -6,6 +6,7 @@
  * Provides spopen and spclose

 FILE * spopen(const char *);
+FILE *spopene(const char *,const char *[]);
 int spclose(FILE *);

  *
@@ -28,6 +29,7 @@
 extern FILE *child_process;

 FILE *spopen(const char *);
+FILE *spopene(const char *,const char *[]);
 int spclose(FILE *);
 RETSIGTYPE popen_timeout_alarm_handler(int);

@@ -67,6 +69,13 @@
 FILE *spopen(const char *cmdstring)
 {
   char *environ[] = {  NULL };
+
+  return(spopene(cmdstring,environ));
+}
+
+FILE *spopene(const char *cmdstring, const char *environ[])
+{
+
   char *cmd=NULL;
   char **argv=NULL;
   char *str;
============================================================================
========
diff -u -r1.1 popen.h
--- popen.h     2002/06/19 18:26:48     1.1
+++ popen.h     2002/06/19 18:27:42
@@ -1,5 +1,6 @@
 /* plugins/popen.h.  Generated automatically by configure.  */
 FILE *spopen(const char *);
+FILE *spopene(const char *,const char *[]);
 int spclose(FILE *);
 RETSIGTYPE popen_timeout_alarm_handler(int);

============================================================================
========
diff -u -r1.1 check_snmp.c
--- check_snmp.c        2002/06/19 17:03:20     1.1
+++ check_snmp.c        2002/06/19 19:03:38
@@ -37,6 +37,9 @@
 #include "utils.h"
 #include "popen.h"

+/* this should go into the makefile */
+#define CHILD_ENV_ARRAY { "LD_LIBRARY_PATH=/usr/local/lib", NULL }
+
 #define PROGNAME check_snmp

 #define mark(a) ((a)!=0?"*":"")
@@ -132,6 +135,7 @@
        char *ptr = NULL;
        char *p2 = NULL;
        char *show = NULL;
+       char *environ[] = CHILD_ENV_ARRAY;

        labels = malloc(labels_size);
        unitv = malloc(unitv_size);
@@ -156,7 +160,7 @@
        }

        /* run the command */
-       child_process = spopen(command_line);
+       child_process = spopene(command_line,environ);
        if (child_process == NULL) {
                printf("Could not open pipe: %s\n", command_line);
                exit(STATE_UNKNOWN);
============================================================================
========

Happy merging,

Karl Ewald
IT Services
IXOS Software AG, Bretonischer Ring 12, 85630 Grasbrunn
Tel. +49.89.4629.1350, Fax +49.89.4629.331350