initgroups(3) Library Functions Manual initgroups(3)
NAME
initgroups - initialize the supplementary group access list
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <sys/types.h>
#include <grp.h>
int initgroups(const char *user, gid_t group);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
initgroups():
Since glibc 2.19:
_DEFAULT_SOURCE
glibc 2.19 and earlier:
_BSD_SOURCE
DESCRIPTION
The initgroups() function initializes the group access list by reading
the group database /etc/group and using all groups of which user is a
member. The additional group group is also added to the list.
The user argument must be non-NULL.
RETURN VALUE
The initgroups() function returns 0 on success. On error, -1 is re-
turned, and errno is set to indicate the error.
ERRORS
ENOMEM Insufficient memory to allocate group information structure.
EPERM The calling process has insufficient privilege. See the underly-
ing system call setgroups(2).
FILES
/etc/group
group database file
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
┌─────────────────────────────────────┬───────────────┬────────────────┐
│ Interface │ Attribute │ Value │
├─────────────────────────────────────┼───────────────┼────────────────┤
│ initgroups() │ Thread safety │ MT-Safe locale │
└─────────────────────────────────────┴───────────────┴────────────────┘
STANDARDS
None.
HISTORY
SVr4, 4.3BSD.
SEE ALSO
getgroups(2), setgroups(2), credentials(7)
Linux man-pages 6.9.1 2024-05-02 initgroups(3)
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