.\" Hey Emacs! This file is -*- nroff -*- source. .\" .\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu) .\" .\" 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. .\" .\" 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this one .\" .\" Since the Linux kernel and libraries are constantly changing, this .\" manual page may be incorrect or out-of-date.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. .\" .\" Modified Thu Oct 31 12:04:29 1996 by Eric S. Raymond .TH GETGROUPS 2 "10 December 1997" "Linux 2.0.32" "Linux Programmer's Manual" .SH NAME getgroups, setgroups \- get/set list of supplementary group IDs .SH SYNOPSIS .B #include .sp .BI "int getgroups(int " size ", gid_t " list []); .sp 2 .B #define __USE_BSD .br .B #include .sp .BI "int setgroups(size_t " size ", const gid_t *" list ); .SH DESCRIPTION .TP .B getgroups Up to .I size supplementary groups are returned in .IR list . If .I size is zero, .I list is not modified, but the total number of supplementary groups for the process is returned. .TP .B setgroups Sets the supplementary groups for the process. Only the super-user may use this function. .SH "RETURN VALUE" .TP .B getgroups On success, the number of supplementary group IDs is returned. On error, \-1 is returned, and .I errno is set appropriately. .TP .B setgroups On success, zero is returned. On error, \-1 is returned, and .I errno is set appropriately. .SH ERRORS .TP .B EFAULT .I list has an invalid address. .TP .B EPERM For .BR setgroups , the user is not the super-user. .TP .B EINVAL For .BR setgroups , .I size is greater than .B NGROUPS (32 for Linux 2.0.32). For .BR getgroups , .I size is less than the number of supplementary group IDs, but is not zero. .SH "CONFORMING TO" SVr4, SVID (issue 4 only; these calls were not present in SVr3), X/OPEN, 4.3BSD. The .B getgroups function is in POSIX.1. Since .B setgroups requires privilege, it is not covered by POSIX.1. .SH BUGS The .B __USE_BSD flag probably shouldn't be required for .BR setgroups . .SH "SEE ALSO" .BR initgroups (3), .BR getgid (2), .BR setgid (2)