diff options
Diffstat (limited to 'man3/getservent_r.3')
| -rw-r--r-- | man3/getservent_r.3 | 249 |
1 files changed, 0 insertions, 249 deletions
diff --git a/man3/getservent_r.3 b/man3/getservent_r.3 deleted file mode 100644 index 76c42f3..0000000 --- a/man3/getservent_r.3 +++ /dev/null @@ -1,249 +0,0 @@ -'\" t -.\" Copyright 2008, Linux Foundation, written by Michael Kerrisk -.\" <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH getservent_r 3 2023-10-31 "Linux man-pages 6.7" -.SH NAME -getservent_r, getservbyname_r, getservbyport_r \- get -service entry (reentrant) -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <netdb.h> -.P -.BI "int getservent_r(struct servent *restrict " result_buf , -.BI " char " buf "[restrict ." buflen "], size_t " buflen , -.BI " struct servent **restrict " result ); -.BI "int getservbyname_r(const char *restrict " name , -.BI " const char *restrict " proto , -.BI " struct servent *restrict " result_buf , -.BI " char " buf "[restrict ." buflen "], size_t " buflen , -.BI " struct servent **restrict " result ); -.BI "int getservbyport_r(int " port , -.BI " const char *restrict " proto , -.BI " struct servent *restrict " result_buf , -.BI " char " buf "[restrict ." buflen "], size_t " buflen , -.BI " struct servent **restrict " result ); -.P -.fi -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.P -.BR getservent_r (), -.BR getservbyname_r (), -.BR getservbyport_r (): -.nf - Since glibc 2.19: - _DEFAULT_SOURCE - glibc 2.19 and earlier: - _BSD_SOURCE || _SVID_SOURCE -.fi -.SH DESCRIPTION -The -.BR getservent_r (), -.BR getservbyname_r (), -and -.BR getservbyport_r () -functions are the reentrant equivalents of, respectively, -.BR getservent (3), -.BR getservbyname (3), -and -.BR getservbyport (3). -They differ in the way that the -.I servent -structure is returned, -and in the function calling signature and return value. -This manual page describes just the differences from -the nonreentrant functions. -.P -Instead of returning a pointer to a statically allocated -.I servent -structure as the function result, -these functions copy the structure into the location pointed to by -.IR result_buf . -.P -The -.I buf -array is used to store the string fields pointed to by the returned -.I servent -structure. -(The nonreentrant functions allocate these strings in static storage.) -The size of this array is specified in -.IR buflen . -If -.I buf -is too small, the call fails with the error -.BR ERANGE , -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 nonreentrant functions use a 1024 byte buffer -- mtk. -.P -If the function call successfully obtains a service record, then -.I *result -is set pointing to -.IR result_buf ; -otherwise, -.I *result -is set to NULL. -.SH RETURN VALUE -On success, these functions return 0. -On error, they return one of the positive error numbers listed in errors. -.P -On error, record not found -.RB ( getservbyname_r (), -.BR getservbyport_r ()), -or end of input -.RB ( getservent_r ()) -.I result -is set to NULL. -.SH ERRORS -.TP -.B ENOENT -.RB ( getservent_r ()) -No more records in database. -.TP -.B ERANGE -.I buf -is too small. -Try again with a larger buffer -(and increased -.IR buflen ). -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.na -.nh -.BR getservent_r (), -.BR getservbyname_r (), -.BR getservbyport_r () -T} Thread safety MT-Safe locale -.TE -.SH VERSIONS -Functions with similar names exist on some other systems, -though typically with different calling signatures. -.SH STANDARDS -GNU. -.SH EXAMPLES -The program below uses -.BR getservbyport_r () -to retrieve the service record for the port and protocol named -in its first command-line argument. -If a third (integer) command-line argument is supplied, -it is used as the initial value for -.IR buflen ; -if -.BR getservbyport_r () -fails with the error -.BR ERANGE , -the program retries with larger buffer sizes. -The following shell session shows a couple of sample runs: -.P -.in +4n -.EX -.RB "$" " ./a.out 7 tcp 1" -ERANGE! Retrying with larger buffer -getservbyport_r() returned: 0 (success) (buflen=87) -s_name=echo; s_proto=tcp; s_port=7; aliases= -.RB "$" " ./a.out 77777 tcp" -getservbyport_r() returned: 0 (success) (buflen=1024) -Call failed/record not found -.EE -.in -.SS Program source -\& -.\" SRC BEGIN (getservent_r.c) -.EX -#define _GNU_SOURCE -#include <ctype.h> -#include <errno.h> -#include <netdb.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -\& -#define MAX_BUF 10000 -\& -int -main(int argc, char *argv[]) -{ - int buflen, erange_cnt, port, s; - struct servent result_buf; - struct servent *result; - char buf[MAX_BUF]; - char *protop; -\& - if (argc < 3) { - printf("Usage: %s port\-num proto\-name [buflen]\en", argv[0]); - exit(EXIT_FAILURE); - } -\& - port = htons(atoi(argv[1])); - protop = (strcmp(argv[2], "null") == 0 || - strcmp(argv[2], "NULL") == 0) ? NULL : argv[2]; -\& - buflen = 1024; - if (argc > 3) - buflen = atoi(argv[3]); -\& - if (buflen > MAX_BUF) { - printf("Exceeded buffer limit (%d)\en", MAX_BUF); - exit(EXIT_FAILURE); - } -\& - erange_cnt = 0; - do { - s = getservbyport_r(port, protop, &result_buf, - buf, buflen, &result); - if (s == ERANGE) { - if (erange_cnt == 0) - printf("ERANGE! Retrying with larger buffer\en"); - erange_cnt++; -\& - /* Increment a byte at a time so we can see exactly - what size buffer was required. */ -\& - buflen++; -\& - if (buflen > MAX_BUF) { - printf("Exceeded buffer limit (%d)\en", MAX_BUF); - exit(EXIT_FAILURE); - } - } - } while (s == ERANGE); -\& - printf("getservbyport_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\en"); - exit(EXIT_FAILURE); - } -\& - printf("s_name=%s; s_proto=%s; s_port=%d; aliases=", - result_buf.s_name, result_buf.s_proto, - ntohs(result_buf.s_port)); - for (char **p = result_buf.s_aliases; *p != NULL; p++) - printf("%s ", *p); - printf("\en"); -\& - exit(EXIT_SUCCESS); -} -.EE -.\" SRC END -.SH SEE ALSO -.BR getservent (3), -.BR services (5) |