PUTGRENT(3) Linux Programmer's Manual PUTGRENT(3)

putgrent - write a group database entry to a file

#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <grp.h>
int putgrent(const struct group *grp, FILE *stream);

The putgrent() function is the counterpart for fgetgrent(3). The function writes the content of the provided struct group into the stream. The list of group members must be NULL-terminated or NULL-initialized.
The struct group is defined as follows:

struct group {
    char   *gr_name;      /* group name */
    char   *gr_passwd;    /* group password */
    gid_t   gr_gid;       /* group ID */
    char  **gr_mem;       /* group members */

The function returns zero on success, and a nonzero value on error.

For an explanation of the terms used in this section, see attributes(7).
Interface Attribute Value
putgrent () Thread safety MT-Safe

This function is a GNU extension.

fgetgrent(3), getgrent(3), group(5)
2017-09-15 GNU