| .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
| .\" |
| .\" Permission is granted to make and distribute verbatim copies of this |
| .\" manual provided the copyright notice and this permission notice are |
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| .\" |
| .\" Permission is granted to copy and distribute modified versions of this |
| .\" manual under the conditions for verbatim copying, provided that the |
| .\" entire resulting derived work is distributed under the terms of a |
| .\" permission notice identical to this one. |
| .\" |
| .\" Since the Linux kernel and libraries are constantly changing, this |
| .\" manual page may be incorrect or out-of-date. The author(s) assume no |
| .\" responsibility for errors or omissions, or for damages resulting from |
| .\" the use of the information contained herein. The author(s) may not |
| .\" have taken the same level of care in the production of this manual, |
| .\" which is licensed free of charge, as they might when working |
| .\" professionally. |
| .\" |
| .\" Formatted or processed versions of this manual, if unaccompanied by |
| .\" the source, must acknowledge the copyright and authors of this work. |
| .\" |
| .\" References consulted: |
| .\" Linux libc source code |
| .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) |
| .\" 386BSD man pages |
| .\" Modified Sat Jul 24 19:29:54 1993 by Rik Faith (faith@cs.unc.edu) |
| .TH GETGRENT 3 2010-10-21 "" "Linux Programmer's Manual" |
| .SH NAME |
| getgrent, setgrent, endgrent \- get group file entry |
| .SH SYNOPSIS |
| .nf |
| .B #include <sys/types.h> |
| .B #include <grp.h> |
| .sp |
| .B struct group *getgrent(void); |
| .sp |
| .B void setgrent(void); |
| .sp |
| .B void endgrent(void); |
| .fi |
| .sp |
| .in -4n |
| Feature Test Macro Requirements for glibc (see |
| .BR feature_test_macros (7)): |
| .in |
| .sp |
| .PD 0 |
| .ad l |
| .BR setgrent (): |
| .RS 4 |
| _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 || |
| _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED || |
| .br |
| /* Since glibc 2.12: */ _POSIX_C_SOURCE\ >=\ 200809L |
| .RE |
| .sp |
| .BR getgrent (), |
| .BR endgrent (): |
| .RS 4 |
| _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500 || |
| _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED |
| .RE |
| .PD |
| .ad b |
| .SH DESCRIPTION |
| The |
| .BR getgrent () |
| function returns a pointer to a structure containing |
| the broken-out fields of a record in the group database |
| (e.g., the local group file |
| .IR /etc/group , |
| NIS, and LDAP). |
| The first time |
| .BR getgrent () |
| is called, |
| it returns the first entry; thereafter, it returns successive entries. |
| .PP |
| The |
| .BR setgrent () |
| function rewinds to the beginning |
| of the group database, to allow repeated scans. |
| .PP |
| The |
| .BR endgrent () |
| function is used to close the group database |
| after all processing has been performed. |
| .PP |
| The \fIgroup\fP structure is defined in \fI<grp.h>\fP as follows: |
| .sp |
| .in +4n |
| .nf |
| struct group { |
| char *gr_name; /* group name */ |
| char *gr_passwd; /* group password */ |
| gid_t gr_gid; /* group ID */ |
| char **gr_mem; /* group members */ |
| }; |
| .fi |
| .in |
| .PP |
| For more information about the fields of this structure, see |
| .BR group (5). |
| .SH "RETURN VALUE" |
| The |
| .BR getgrent () |
| function returns a pointer to a |
| .I group |
| structure, |
| or NULL if there are no more entries or an error occurs. |
| .LP |
| Upon error, |
| .I errno |
| may be set. |
| If one wants to check |
| .I errno |
| after the call, it should be set to zero before the call. |
| |
| The return value may point to a static area, and may be overwritten |
| by subsequent calls to |
| .BR getgrent (), |
| .BR getgrgid (3), |
| or |
| .BR getgrnam (3). |
| (Do not pass the returned pointer to |
| .BR free (3).) |
| .SH ERRORS |
| .TP |
| .B EINTR |
| A signal was caught. |
| .TP |
| .B EIO |
| I/O error. |
| .TP |
| .B EMFILE |
| The calling process already has too many open files. |
| .TP |
| .B ENFILE |
| Too many open files in the system. |
| .TP |
| .B ENOMEM |
| .\" not in POSIX |
| Insufficient memory to allocate |
| .I group |
| structure. |
| .TP |
| .B ERANGE |
| Insufficient buffer space supplied. |
| .SH FILES |
| .TP |
| .I /etc/group |
| local group database file |
| .SH "CONFORMING TO" |
| SVr4, 4.3BSD, POSIX.1-2001. |
| .SH "SEE ALSO" |
| .BR fgetgrent (3), |
| .BR getgrent_r (3), |
| .BR getgrgid (3), |
| .BR getgrnam (3), |
| .BR getgrouplist (3), |
| .BR putgrent (3), |
| .BR group (5) |