Merging upstream version 6.8.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 228 insertions, 0 deletions

diff --git a/man/man3/getgrent_r.3 b/man/man3/getgrent_r.3
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+'\" t
+.\" Copyright (c) 2003 Andries Brouwer (aeb@cwi.nl)
+.\"
+.\" SPDX-License-Identifier: GPL-2.0-or-later
+.\"
+.TH getgrent_r 3 2024-05-02 "Linux man-pages (unreleased)"
+.SH NAME
+getgrent_r, fgetgrent_r \- get group file entry reentrantly
+.SH LIBRARY
+Standard C library
+.RI ( libc ", " \-lc )
+.SH SYNOPSIS
+.nf
+.B #include <grp.h>
+.P
+.BI "int getgrent_r(struct group *restrict " gbuf ,
+.BI "               char " buf "[restrict ." buflen "], size_t " buflen ,
+.BI "               struct group **restrict " gbufp );
+.BI "int fgetgrent_r(FILE *restrict " stream ", struct group *restrict " gbuf ,
+.BI "               char " buf "[restrict ." buflen "], size_t " buflen ,
+.BI "               struct group **restrict " gbufp );
+.fi
+.P
+.RS -4
+Feature Test Macro Requirements for glibc (see
+.BR feature_test_macros (7)):
+.RE
+.P
+.BR getgrent_r ():
+.nf
+    _GNU_SOURCE
+.fi
+.\" FIXME . The FTM requirements seem inconsistent here.  File a glibc bug?
+.P
+.BR fgetgrent_r ():
+.nf
+    Since glibc 2.19:
+        _DEFAULT_SOURCE
+    glibc 2.19 and earlier:
+        _SVID_SOURCE
+.fi
+.SH DESCRIPTION
+The functions
+.BR getgrent_r ()
+and
+.BR fgetgrent_r ()
+are the reentrant versions of
+.BR getgrent (3)
+and
+.BR fgetgrent (3).
+The former reads the next group entry from the stream initialized by
+.BR setgrent (3).
+The latter reads the next group entry from
+.IR stream .
+.P
+The \fIgroup\fP structure is defined in
+.I <grp.h>
+as follows:
+.P
+.in +4n
+.EX
+struct group {
+    char   *gr_name;        /* group name */
+    char   *gr_passwd;      /* group password */
+    gid_t   gr_gid;         /* group ID */
+    char  **gr_mem;         /* NULL\-terminated array of pointers
+                               to names of group members */
+};
+.EE
+.in
+.P
+For more information about the fields of this structure, see
+.BR group (5).
+.P
+The nonreentrant functions return a pointer to static storage,
+where this static storage contains further pointers to group
+name, password, and members.
+The reentrant functions described here return all of that in
+caller-provided buffers.
+First of all there is the buffer
+.I gbuf
+that can hold a \fIstruct group\fP.
+And next the buffer
+.I buf
+of size
+.I buflen
+that can hold additional strings.
+The result of these functions, the \fIstruct group\fP read from the stream,
+is stored in the provided buffer
+.IR *gbuf ,
+and a pointer to this \fIstruct group\fP is returned in
+.IR *gbufp .
+.SH RETURN VALUE
+On success, these functions return 0 and
+.I *gbufp
+is a pointer to the \fIstruct group\fP.
+On error, these functions return an error value and
+.I *gbufp
+is NULL.
+.SH ERRORS
+.TP
+.B ENOENT
+No more entries.
+.TP
+.B ERANGE
+Insufficient buffer space supplied.
+Try again with larger buffer.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lb lb lbx
+l l l.
+Interface	Attribute	Value
+T{
+.na
+.nh
+.BR getgrent_r ()
+T}	Thread safety	T{
+.na
+.nh
+MT-Unsafe race:grent locale
+T}
+T{
+.na
+.nh
+.BR fgetgrent_r ()
+T}	Thread safety	T{
+.na
+.nh
+MT-Safe
+T}
+.TE
+.P
+In the above table,
+.I grent
+in
+.I race:grent
+signifies that if any of the functions
+.BR setgrent (3),
+.BR getgrent (3),
+.BR endgrent (3),
+or
+.BR getgrent_r ()
+are used in parallel in different threads of a program,
+then data races could occur.
+.SH VERSIONS
+Other systems use the prototype
+.P
+.in +4n
+.EX
+struct group *getgrent_r(struct group *grp, char *buf,
+                         int buflen);
+.EE
+.in
+.P
+or, better,
+.P
+.in +4n
+.EX
+int getgrent_r(struct group *grp, char *buf, int buflen,
+               FILE **gr_fp);
+.EE
+.in
+.SH STANDARDS
+GNU.
+.SH HISTORY
+These functions are done in a style resembling
+the POSIX version of functions like
+.BR getpwnam_r (3).
+.SH NOTES
+The function
+.BR getgrent_r ()
+is not really reentrant since it shares the reading position
+in the stream with all other threads.
+.SH EXAMPLES
+.\" SRC BEGIN (getgrent_r.c)
+.EX
+#define _GNU_SOURCE
+#include <grp.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#define BUFLEN 4096
+\&
+int
+main(void)
+{
+    struct group grp;
+    struct group *grpp;
+    char buf[BUFLEN];
+    int i;
+\&
+    setgrent();
+    while (1) {
+        i = getgrent_r(&grp, buf, sizeof(buf), &grpp);
+        if (i)
+            break;
+        printf("%s (%jd):", grpp\->gr_name, (intmax_t) grpp\->gr_gid);
+        for (size_t j = 0; ; j++) {
+            if (grpp\->gr_mem[j] == NULL)
+                break;
+            printf(" %s", grpp\->gr_mem[j]);
+        }
+        printf("\en");
+    }
+    endgrent();
+    exit(EXIT_SUCCESS);
+}
+.EE
+.\" perhaps add error checking - should use strerror_r
+.\" #include <errno.h>
+.\" #include <stdlib.h>
+.\"         if (i) {
+.\"               if (i == ENOENT)
+.\"                     break;
+.\"               printf("getgrent_r: %s", strerror(i));
+.\"               exit(EXIT_FAILURE);
+.\"         }
+.\" SRC END
+.SH SEE ALSO
+.BR fgetgrent (3),
+.BR getgrent (3),
+.BR getgrgid (3),
+.BR getgrnam (3),
+.BR putgrent (3),
+.BR group (5)