ENVZ_ADD(3)                                                                           ENVZ_ADD(3)



NAME
       envz_add,  envz_entry,  envz_get, envz_merge, envz_remove, envz_strip - environment string
       support

SYNOPSIS
       #include 

       error_t
       envz_add(char **envz, size_t *envz_len,
                const char *name, const char *value);

       char *
       envz_entry(const char *envz, size_t *envz_len, const char *name);

       char *
       envz_get(const char *envz, size_t *envz_len, const char *name);

       error_t
       envz_merge(char **envz, size_t *envz_len,
                const char *envz2, size_t envz2_len, int override);

       void
       envz_remove(char **envz, size_t *envz_len, const char *name);

       void
       envz_strip(char **envz, size_t *envz_len);


DESCRIPTION
       These functions are glibc-specific.

       An argz vector is a pointer to a character buffer together with a length, see argz_add(3).
       An  envz  vector  is  a  special  argz  vector, namely one where the strings have the form
       "name=value". Everything after the first '=' is considered to be the value. If there is no
       '=',  the  value  is  taken to be NULL.  (While the value in case of a trailing '=' is the
       empty string "".)

       These functions are for handling envz vectors.

       envz_add() adds the string "name=value" (in case value is non-NULL)  or  "name"  (in  case
       value  is  NULL) to the envz vector (*envz,*envz_len) and updates *envz and *envz_len.  If
       an entry with the same name existed, it is removed.

       envz_entry() looks for name in the envz vector (envz,envz_len) and returns  the  entry  if
       found, or NULL if not.

       envz_get()  looks  for  name  in  the envz vector (envz,envz_len) and returns the value if
       found, or NULL if not.  (Note that the value can also be NULL, namely  when  there  is  an
       entry for name without '=' sign.)

       envz_merge()  adds  each  entry  in envz2 to *envz, as if with envz_add().  If override is
       true, then values in envz2 will supersede those with the same  name  in  *envz,  otherwise
       not.

       envz_remove() removes the entry for name from (*envz,*envz_len) if there was one.

       envz_strip removes all entries with value NULL.

RETURN VALUE
       All  envz  functions that do memory allocation have a return type of error_t, and return 0
       for success, and ENOMEM if an allocation error occurs.

EXAMPLE
       #include 
       #include 
       int
       main(int argc, char *argv[], char *envp[]) {
            int i, e_len = 0;
            char *str;

            for (i=0; envp[i] != NULL; i++)
                 e_len += strlen(envp[i]) + 1;

            str = envz_entry(*envp, e_len, "HOME");
            printf("%s\n", str);
            str = envz_get(*envp, e_len, "HOME");
            printf("%s\n", str);
            return 0;
       }

NOTES
       These functions are a GNU extension. Handle with care.

SEE ALSO
       argz(3)



                                                                                      ENVZ_ADD(3)