.\" Copyright 2008, Linux Foundation, written by Michael Kerrisk
.\" <mtk.manpages@gmail.com>
.\"
+.\" %%%LICENSE_START(VERBATIM)
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
+.\" %%%LICENSE_END
.\"
-.TH GETPROTOENT_R 3 2008-08-19 "GNU" "Linux Programmer's Manual"
+.TH GETPROTOENT_R 3 2019-03-06 "GNU" "Linux Programmer's Manual"
.SH NAME
getprotoent_r, getprotobyname_r, getprotobynumber_r \- get
protocol entry (reentrant)
.SH SYNOPSIS
.nf
.B #include <netdb.h>
-.sp
+.PP
.BI "int getprotoent_r(struct protoent *" result_buf ", char *" buf ,
.BI " size_t " buflen ", struct protoent **" result );
-.sp
+.PP
.BI "int getprotobyname_r(const char *" name ,
.BI " struct protoent *" result_buf ", char *" buf ,
.BI " size_t " buflen ", struct protoent **" result );
-.sp
+.PP
.BI "int getprotobynumber_r(int " proto ,
.BI " struct protoent *" result_buf ", char *" buf ,
.BI " size_t " buflen ", struct protoent **" result );
-.sp
+.PP
.fi
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.ad l
.in
-.sp
+.PP
.BR getprotoent_r (),
.BR getprotobyname_r (),
.BR getprotobynumber_r ():
-_BSD_SOURCE || _SVID_SOURCE
+ Since glibc 2.19:
+ _DEFAULT_SOURCE
+ Glibc 2.19 and earlier:
+ _BSD_SOURCE || _SVID_SOURCE
.ad b
.SH DESCRIPTION
The
structure is returned,
and in the function calling signature and return value.
This manual page describes just the differences from
-the non-reentrant functions.
-
+the nonreentrant functions.
+.PP
Instead of returning a pointer to a statically allocated
.I protoent
structure as the function result,
these functions copy the structure into the location pointed to by
.IR result_buf .
-
+.PP
The
.I buf
array is used to store the string fields pointed to by the returned
.I protoent
structure.
-(The non-reentrant functions allocate these strings in static storage.)
+(The nonreentrant functions allocate these strings in static storage.)
The size of this array is specified in
.IR buflen .
If
and the caller must try again with a larger buffer.
(A buffer of length 1024 bytes should be sufficient for most applications.)
.\" I can find no information on the required/recommended buffer size;
-.\" the non-reentrant functions use a 1024 byte buffer.
+.\" the nonreentrant functions use a 1024 byte buffer.
.\" The 1024 byte value is also what the Solaris man page suggests. -- mtk
-
+.PP
If the function call successfully obtains a protocol record, then
.I *result
is set pointing to
otherwise,
.I *result
is set to NULL.
-.SH "RETURN VALUE"
+.SH RETURN VALUE
On success, these functions return 0.
-On error, a positive error number is returned.
-
+On error, they return one of the positive error numbers listed in ERRORS.
+.PP
On error, record not found
.RB ( getprotobyname_r (),
.BR getprotobynumber_r ()),
Try again with a larger buffer
(and increased
.IR buflen ).
-.SH "CONFORMING TO"
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lbw20 lb lb
+l l l.
+Interface Attribute Value
+T{
+.BR getprotoent_r (),
+.br
+.BR getprotobyname_r (),
+.br
+.BR getprotobynumber_r ()
+T} Thread safety MT-Safe locale
+.TE
+.sp 1
+.SH CONFORMING TO
These functions are GNU extensions.
Functions with similar names exist on some other systems,
though typically with different calling signatures.
.BR ERANGE ,
the program retries with larger buffer sizes.
The following shell session shows a couple of sample runs:
+.PP
.in +4n
-.nf
-
-$ ./a.out tcp 1
+.EX
+.RB "$" " ./a.out tcp 1"
ERANGE! Retrying with larger buffer
getprotobyname_r() returned: 0 (success) (buflen=78)
p_name=tcp; p_proto=6; aliases=TCP
-$ ./a.out xxx 1
+.RB "$" " ./a.out xxx 1"
ERANGE! Retrying with larger buffer
getprotobyname_r() returned: 0 (success) (buflen=100)
Call failed/record not found
-
-.fi
+.EE
.in
-.nf
+.SS Program source
+\&
+.EX
#define _GNU_SOURCE
#include <ctype.h>
#include <netdb.h>
char **p;
if (argc < 2) {
- printf("Usage: %s proto\-name [buflen]\\n", argv[0]);
+ printf("Usage: %s proto\-name [buflen]\en", argv[0]);
exit(EXIT_FAILURE);
}
buflen = atoi(argv[2]);
if (buflen > MAX_BUF) {
- printf("Exceeded buffer limit (%d)\\n", MAX_BUF);
+ printf("Exceeded buffer limit (%d)\en", MAX_BUF);
exit(EXIT_FAILURE);
}
buf, buflen, &result);
if (s == ERANGE) {
if (erange_cnt == 0)
- printf("ERANGE! Retrying with larger buffer\\n");
+ printf("ERANGE! Retrying with larger buffer\en");
erange_cnt++;
/* Increment a byte at a time so we can see exactly
buflen++;
if (buflen > MAX_BUF) {
- printf("Exceeded buffer limit (%d)\\n", MAX_BUF);
+ printf("Exceeded buffer limit (%d)\en", MAX_BUF);
exit(EXIT_FAILURE);
}
}
} while (s == ERANGE);
- printf("getprotobyname_r() returned: %s (buflen=%d)\\n",
+ printf("getprotobyname_r() returned: %s (buflen=%d)\en",
(s == 0) ? "0 (success)" : (s == ENOENT) ? "ENOENT" :
strerror(s), buflen);
if (s != 0 || result == NULL) {
- printf("Call failed/record not found\\n");
+ printf("Call failed/record not found\en");
exit(EXIT_FAILURE);
}
result_buf.p_name, result_buf.p_proto);
for (p = result_buf.p_aliases; *p != NULL; p++)
printf("%s ", *p);
- printf("\\n");
+ printf("\en");
exit(EXIT_SUCCESS);
}
-.fi
-.SH "SEE ALSO"
+.EE
+.SH SEE ALSO
.BR getprotoent (3),
.BR protocols (5)
projects / thirdparty / man-pages.git / blobdiff