1GETNETENT_R(3) Linux Programmer's Manual GETNETENT_R(3)
2
6 getnetent_r, getnetbyname_r, getnetbyaddr_r - get network entry (reen‐
7 trant)
8
10 #include <netdb.h>
11 int getnetent_r(struct netent *restrict result_buf,
13 char *restrict buf, size_t buflen,
14 struct netent **restrict result,
15 int *restrict h_errnop);
16 int getnetbyname_r(const char *restrict name,
17 struct netent *restrict result_buf,
18 char *restrict buf, size_t buflen,
19 struct netent **restrict result,
20 int *restrict h_errnop);
21 int getnetbyaddr_r(uint32_t net, int type,
22 struct netent *restrict result_buf,
23 char *restrict buf, size_t buflen,
24 struct netent **restrict result,
25 int *restrict h_errnop);
26 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
28 getnetent_r(), getnetbyname_r(), getnetbyaddr_r():
30 Since glibc 2.19:
31 _DEFAULT_SOURCE
32 Glibc 2.19 and earlier:
33 _BSD_SOURCE || _SVID_SOURCE
34
36 The getnetent_r(), getnetbyname_r(), and getnetbyaddr_r() functions are
37 the reentrant equivalents of, respectively, getnetent(3), getnetby‐
38 name(3), and getnetbynumber(3). They differ in the way that the netent
39 structure is returned, and in the function calling signature and return
40 value. This manual page describes just the differences from the non‐
41 reentrant functions.
42 Instead of returning a pointer to a statically allocated netent struc‐
44 ture as the function result, these functions copy the structure into
45 the location pointed to by result_buf.
46 The buf array is used to store the string fields pointed to by the re‐
48 turned netent structure. (The nonreentrant functions allocate these
49 strings in static storage.) The size of this array is specified in bu‐
50 flen. If buf is too small, the call fails with the error ERANGE, and
51 the caller must try again with a larger buffer. (A buffer of length
52 1024 bytes should be sufficient for most applications.)
53 If the function call successfully obtains a network record, then *re‐
55 sult is set pointing to result_buf; otherwise, *result is set to NULL.
56 The buffer pointed to by h_errnop is used to return the value that
58 would be stored in the global variable h_errno by the nonreentrant ver‐
59 sions of these functions.
60
62 On success, these functions return 0. On error, they return one of the
63 positive error numbers listed in ERRORS.
64 On error, record not found (getnetbyname_r(), getnetbyaddr_r()), or end
66 of input (getnetent_r()) result is set to NULL.
67
69 ENOENT (getnetent_r()) No more records in database.
70 ERANGE buf is too small. Try again with a larger buffer (and increased
72 buflen).
73
75 For an explanation of the terms used in this section, see at‐
76 tributes(7).
77 ┌─────────────────────────────────────┬───────────────┬────────────────┐
79 │Interface │ Attribute │ Value │
80 ├─────────────────────────────────────┼───────────────┼────────────────┤
81 │getnetent_r(), getnetbyname_r(), │ Thread safety │ MT-Safe locale │
82 │getnetbyaddr_r() │ │ │
83 └─────────────────────────────────────┴───────────────┴────────────────┘
84
86 These functions are GNU extensions. Functions with similar names exist
87 on some other systems, though typically with different calling signa‐
88 tures.
89
91 getnetent(3), networks(5)
92
94 This page is part of release 5.13 of the Linux man-pages project. A
95 description of the project, information about reporting bugs, and the
96 latest version of this page, can be found at
97 https://www.kernel.org/doc/man-pages/.
98GNU 2021-03-22 GETNETENT_R(3)