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GETGRNAM(3P)               POSIX Programmer's Manual              GETGRNAM(3P)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may dif-
       fer (consult the corresponding Linux manual page for details of Linux behavior), or the interface  may  not  be
       implemented on Linux.

NAME
       getgrnam, getgrnam_r - search group database for a name

SYNOPSIS
       #include <grp.h>

       struct group *getgrnam(const char *name);


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


DESCRIPTION
       The getgrnam() function shall search the group database for an entry with a matching name.

       The  getgrnam() function need not be reentrant. A function that is not required to be reentrant is not required
       to be thread-safe.

       The getgrnam_r() function shall update the group structure pointed to by grp and store a pointer to that struc-
       ture  at the location pointed to by result. The structure shall contain an entry from the group database with a
       matching gid or name. Storage referenced by the group structure is allocated from the memory provided with  the
       buffer  parameter,  which  is  bufsize bytes in size. The maximum size needed for this buffer can be determined
       with the {_SC_GETGR_R_SIZE_MAX} sysconf() parameter. A NULL pointer is returned at the location pointed  to  by
       result on error or if the requested entry is not found.

RETURN VALUE
       The  getgrnam()  function shall return a pointer to a struct group with the structure defined in <grp.h> with a
       matching entry if one is found. The getgrnam() function shall return a null pointer  if  either  the  requested
       entry was not found, or an error occurred. On error, errno shall be set to indicate the error.

       The  return  value  may  point  to  a static area which is overwritten by a subsequent call to getgrent(), get-
       grgid(), or getgrnam().

       If successful, the getgrnam_r() function shall return zero; otherwise, an error number  shall  be  returned  to
       indicate the error.

ERRORS
       The getgrnam() and getgrnam_r() functions may fail if:

       EIO    An I/O error has occurred.

       EINTR  A signal was caught during getgrnam().

       EMFILE {OPEN_MAX} file descriptors are currently open in the calling process.

       ENFILE The maximum allowable number of files is currently open in the system.


       The getgrnam_r() function may fail if:

       ERANGE Insufficient  storage  was  supplied  via buffer and bufsize to contain the data to be referenced by the
              resulting group structure.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Applications wishing to check for error situations should set errno to 0 before calling getgrnam(). If errno is
       set on return, an error occurred.

       The  getgrnam_r() function is thread-safe and shall return values in a user-supplied buffer instead of possibly
       using a static data area that may be overwritten by each call.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       endgrent(), getgrgid(), the Base Definitions volume of IEEE Std 1003.1-2001, <grp.h>, <limits.h>, <sys/types.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Stan-
       dard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base  Specifica-
       tions  Issue  6,  Copyright (C) 2001-2003 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 Stan-
       dard,  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 .



IEEE/The Open Group                  2003                         GETGRNAM(3P)