getnetent_r(3) — Linux manual page

getnetent_r(3)          Library Functions Manual          getnetent_r(3)

NAME

       getnetent_r, getnetbyname_r, getnetbyaddr_r - get network entry
       (reentrant)

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <netdb.h>

       int getnetent_r(struct netent *restrict result_buf,
                       char buf[restrict .buflen], size_t buflen,
                       struct netent **restrict result,
                       int *restrict h_errnop);
       int getnetbyname_r(const char *restrict name,
                       struct netent *restrict result_buf,
                       char buf[restrict .buflen], size_t buflen,
                       struct netent **restrict result,
                       int *restrict h_errnop);
       int getnetbyaddr_r(uint32_t net, int type,
                       struct netent *restrict result_buf,
                       char buf[restrict .buflen], size_t buflen,
                       struct netent **restrict result,
                       int *restrict h_errnop);

   Feature Test Macro Requirements for glibc (see
   feature_test_macros(7)):

       getnetent_r(), getnetbyname_r(), getnetbyaddr_r():
           Since glibc 2.19:
               _DEFAULT_SOURCE
           glibc 2.19 and earlier:
               _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

       The getnetent_r(), getnetbyname_r(), and getnetbyaddr_r()
       functions are the reentrant equivalents of, respectively,
       getnetent(3), getnetbyname(3), and getnetbynumber(3).  They
       differ in the way that the netent structure is returned, and in
       the function calling signature and return value.  This manual
       page describes just the differences from the nonreentrant
       functions.

       Instead of returning a pointer to a statically allocated netent
       structure as the function result, these functions copy the
       structure into the location pointed to by result_buf.

       The buf array is used to store the string fields pointed to by
       the returned netent structure.  (The nonreentrant functions
       allocate these strings in static storage.)  The size of this
       array is specified in buflen.  If buf is too small, the call
       fails with the error ERANGE, and the caller must try again with a
       larger buffer.  (A buffer of length 1024 bytes should be
       sufficient for most applications.)

       If the function call successfully obtains a network record, then
       *result is set pointing to result_buf; otherwise, *result is set
       to NULL.

       The buffer pointed to by h_errnop is used to return the value
       that would be stored in the global variable h_errno by the
       nonreentrant versions of these functions.

RETURN VALUE

       On success, these functions return 0.  On error, they return one
       of the positive error numbers listed in ERRORS.

       On error, record not found (getnetbyname_r(), getnetbyaddr_r()),
       or end of input (getnetent_r()) result is set to NULL.

ERRORS

       ENOENT (getnetent_r()) No more records in database.

       ERANGE buf is too small.  Try again with a larger buffer (and
              increased buflen).

ATTRIBUTES

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌──────────────────────────────┬───────────────┬────────────────┐
       │ Interface                    │ Attribute     │ Value          │
       ├──────────────────────────────┼───────────────┼────────────────┤
       │ getnetent_r(),               │ Thread safety │ MT-Safe locale │
       │ getnetbyname_r(),            │               │                │
       │ getnetbyaddr_r()             │               │                │
       └──────────────────────────────┴───────────────┴────────────────┘

VERSIONS

       Functions with similar names exist on some other systems, though
       typically with different calling signatures.

STANDARDS

       GNU.

SEE ALSO

       getnetent(3), networks(5)

COLOPHON

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
       version of the page, or you believe there is a better or more up-
       to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not
       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02                 getnetent_r(3)

Pages that refer to this page: getnetent(3)

---