getgrnam_r()

Get information about the group with a given name

Synopsis:

#include <sys/types.h>
#include <grp.h>

int getgrnam_r( const char* name, 
                struct group* grp, 
                char* buffer, 
                size_t bufsize, 
                struct group** result );

Library:

libc

Description:

If _POSIX_THREAD_SAFE_FUNCTIONS is defined, the getgrnam_r() function updates the group structure pointed by grp and stores a pointer to that structure at the location pointed by result. The structure contains an entry from the group database with a matching name.

Storage referenced by the group structure will be allocated from the memory provided with the buffer parameter, which is bufsize characters in size. The maximum size needed for this buffer can be determined by calling sysconf() with an argument of _SC_GETGR_R_SIZE_MAX.

A NULL pointer is stored at the location pointed by result on error or if the requested entry isn't found.

Returns:

Zero for success, or an error number if an error occurred.

Errors:

ERANGE

Insufficient storage was supplied via buffer and bufsize to contain the group structure.

The getgrnam_r() function uses the following functions, and as a result errno can be set to a valid error for any of these calls:

• fclose()
• fgets()
• fopen()
• fseek()
• rewind()

Classification:

POSIX 1003.1

See also:

getgrgid(), getgrgid_r(), getgrnam(), getlogin(), sysconf()