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

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

       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.

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

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

       Standard C library (libc, -lc)

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

       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.

getnetent(3), networks(5)

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

       GNU.

#include<netdb.h>intgetnetent_r(structnetent*restrictresult_buf,charbuf[restrict.buflen],size_tbuflen,structnetent**restrictresult,int*restricth_errnop);intgetnetbyname_r(constchar*restrictname,structnetent*restrictresult_buf,charbuf[restrict.buflen],size_tbuflen,structnetent**restrictresult,int*restricth_errnop);intgetnetbyaddr_r(uint32_tnet,inttype,structnetent*restrictresult_buf,charbuf[restrict.buflen],size_tbuflen,structnetent**restrictresult,int*restricth_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

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