man3/getrpcent_r.3

   1 .\" Copyright 2008, Linux Foundation, written by Michael Kerrisk
   2 .\"     <mtk.manpages@gmail.com>
   3 .\"
   4 .\" %%%LICENSE_START(VERBATIM)
   5 .\" Permission is granted to make and distribute verbatim copies of this
   6 .\" manual provided the copyright notice and this permission notice are
   7 .\" preserved on all copies.
   8 .\"
   9 .\" Permission is granted to copy and distribute modified versions of this
  10 .\" manual under the conditions for verbatim copying, provided that the
  11 .\" entire resulting derived work is distributed under the terms of a
  12 .\" permission notice identical to this one.
  13 .\"
  14 .\" Since the Linux kernel and libraries are constantly changing, this
  15 .\" manual page may be incorrect or out-of-date.  The author(s) assume no
  16 .\" responsibility for errors or omissions, or for damages resulting from
  17 .\" the use of the information contained herein.  The author(s) may not
  18 .\" have taken the same level of care in the production of this manual,
  19 .\" which is licensed free of charge, as they might when working
  20 .\" professionally.
  21 .\"
  22 .\" Formatted or processed versions of this manual, if unaccompanied by
  23 .\" the source, must acknowledge the copyright and authors of this work.
  24 .\" %%%LICENSE_END
  25 .\"
  26 .TH GETRPCENT_R 3  2017-09-15 "GNU" "Linux Programmer's Manual"
  27 .SH NAME
  28 getrpcent_r, getrpcbyname_r, getrpcbynumber_r \- get
  29 RPC entry (reentrant)
  30 .SH SYNOPSIS
  31 .nf
  32 .B #include <netdb.h>
  33 .PP
  34 .BI "int getrpcent_r(struct rpcent *" result_buf ", char *" buf ,
  35 .BI "                size_t " buflen ", struct rpcent **" result );
  36 .PP
  37 .BI "int getrpcbyname_r(const char *" name ,
  38 .BI "                struct rpcent *" result_buf ", char *" buf ,
  39 .BI "                size_t " buflen ", struct rpcent **" result );
  40 .PP
  41 .BI "int getrpcbynumber_r(int " number ,
  42 .BI "                struct rpcent *" result_buf ", char *" buf ,
  43 .BI "                size_t " buflen ", struct rpcent **" result );
  44 .PP
  45 .fi
  46 .in -4n
  47 Feature Test Macro Requirements for glibc (see
  48 .BR feature_test_macros (7)):
  49 .ad l
  50 .in
  51 .PP
  52 .BR getrpcent_r (),
  53 .BR getrpcbyname_r (),
  54 .BR getrpcbynumber_r ():
  55     Since glibc 2.19:
  56         _DEFAULT_SOURCE
  57     Glibc 2.19 and earlier:
  58         _BSD_SOURCE || _SVID_SOURCE
  59 .ad b
  60 .SH DESCRIPTION
  61 The
  62 .BR getrpcent_r (),
  63 .BR getrpcbyname_r (),
  64 and
  65 .BR getrpcbynumber_r ()
  66 functions are the reentrant equivalents of, respectively,
  67 .BR getrpcent (3),
  68 .BR getrpcbyname (3),
  69 and
  70 .BR getrpcbynumber (3).
  71 They differ in the way that the
  72 .I rpcent
  73 structure is returned,
  74 and in the function calling signature and return value.
  75 This manual page describes just the differences from
  76 the nonreentrant functions.
  77 .PP
  78 Instead of returning a pointer to a statically allocated
  79 .I rpcent
  80 structure as the function result,
  81 these functions copy the structure into the location pointed to by
  82 .IR result_buf .
  83 .PP
  84 The
  85 .I buf
  86 array is used to store the string fields pointed to by the returned
  87 .I rpcent
  88 structure.
  89 (The nonreentrant functions allocate these strings in static storage.)
  90 The size of this array is specified in
  91 .IR buflen .
  92 If
  93 .I buf
  94 is too small, the call fails with the error
  95 .BR ERANGE ,
  96 and the caller must try again with a larger buffer.
  97 (A buffer of length 1024 bytes should be sufficient for most applications.)
  98 .\" I can find no information on the required/recommended buffer size;
  99 .\" the nonreentrant functions use a 1024 byte buffer -- mtk.
 100 .PP
 101 If the function call successfully obtains an RPC record, then
 102 .I *result
 103 is set pointing to
 104 .IR result_buf ;
 105 otherwise,
 106 .I *result
 107 is set to NULL.
 108 .SH RETURN VALUE
 109 On success, these functions return 0.
 110 On error, they return one of the positive error numbers listed in ERRORS.
 111 .PP
 112 On error, record not found
 113 .RB ( getrpcbyname_r (),
 114 .BR getrpcbynumber_r ()),
 115 or end of input
 116 .RB ( getrpcent_r ())
 117 .I result
 118 is set to NULL.
 119 .SH ERRORS
 120 .TP
 121 .B ENOENT
 122 .RB ( getrpcent_r ())
 123 No more records in database.
 124 .TP
 125 .B ERANGE
 126 .I buf
 127 is too small.
 128 Try again with a larger buffer
 129 (and increased
 130 .IR buflen ).
 131 .SH ATTRIBUTES
 132 For an explanation of the terms used in this section, see
 133 .BR attributes (7).
 134 .ad l
 135 .TS
 136 allbox;
 137 lbw19 lb lb
 138 l l l.
 139 Interface       Attribute       Value
 140 T{
 141 .BR getrpcent_r (),
 142 .BR getrpcbyname_r (),
 143 .BR getrpcbynumber_r ()
 144 T}      Thread safety   MT-Safe locale
 145 .TE
 146 .ad
 147 .SH CONFORMING TO
 148 These functions are GNU extensions.
 149 Functions with similar names exist on some other systems,
 150 though typically with different calling signatures.
 151 .SH SEE ALSO
 152 .BR getrpcent (3),
 153 .BR rpc (5)