This manual page is part of the POSIX Programmer’s Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
grp.h — group structure
The <grp.h> header shall declare the group structure, which shall include the following members:
The name of the group.
gid_t gr_gid Numerical group ID.
char **gr_mem Pointer to a null-terminated array of character
pointers to member names.
The <grp.h> header shall define the gid_t and size_t types as described in <sys/types.h>.
The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.
struct group *getgrent(void);
struct group *getgrgid(gid_t);
int getgrgid_r(gid_t, struct group *, char *,
size_t, struct group **);
struct group *getgrnam(const char *);
int getgrnam_r(const char *, struct group *, char *,
size_t , struct group **);
The following sections are informative.
The System Interfaces volume of POSIX.1-2017, endgrent(), getgrgid(), getgrnam()
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .