1GETGRNAM(3P) POSIX Programmer's Manual GETGRNAM(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 getgrnam, getgrnam_r - search group database for a name
13
15 #include <grp.h>
16 struct group *getgrnam(const char *name);
18 int getgrnam_r(const char *name, struct group *grp, char *buffer,
21 size_t bufsize, struct group **result);
22
25 The getgrnam() function shall search the group database for an entry
26 with a matching name.
27 The getgrnam() function need not be reentrant. A function that is not
29 required to be reentrant is not required to be thread-safe.
30 The getgrnam_r() function shall update the group structure pointed to
32 by grp and store a pointer to that structure at the location pointed to
33 by result. The structure shall contain an entry from the group database
34 with a matching gid or name. Storage referenced by the group structure
35 is allocated from the memory provided with the buffer parameter, which
36 is bufsize bytes in size. The maximum size needed for this buffer can
37 be determined with the {_SC_GETGR_R_SIZE_MAX} sysconf() parameter. A
38 NULL pointer is returned at the location pointed to by result on error
39 or if the requested entry is not found.
40
42 The getgrnam() function shall return a pointer to a struct group with
43 the structure defined in <grp.h> with a matching entry if one is found.
44 The getgrnam() function shall return a null pointer if either the
45 requested entry was not found, or an error occurred. On error, errno
46 shall be set to indicate the error.
47 The return value may point to a static area which is overwritten by a
49 subsequent call to getgrent(), getgrgid(), or getgrnam().
50 If successful, the getgrnam_r() function shall return zero; otherwise,
52 an error number shall be returned to indicate the error.
53
55 The getgrnam() and getgrnam_r() functions may fail if:
56 EIO An I/O error has occurred.
58 EINTR A signal was caught during getgrnam().
60 EMFILE {OPEN_MAX} file descriptors are currently open in the calling
62 process.
63 ENFILE The maximum allowable number of files is currently open in the
65 system.
66 The getgrnam_r() function may fail if:
69 ERANGE Insufficient storage was supplied via buffer and bufsize to con‐
71 tain the data to be referenced by the resulting group structure.
72 The following sections are informative.
75
77 None.
78
80 Applications wishing to check for error situations should set errno to
81 0 before calling getgrnam(). If errno is set on return, an error
82 occurred.
83 The getgrnam_r() function is thread-safe and shall return values in a
85 user-supplied buffer instead of possibly using a static data area that
86 may be overwritten by each call.
87
89 None.
90
92 None.
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95 endgrent(), getgrgid(), the Base Definitions volume of
96 IEEE Std 1003.1-2001, <grp.h>, <limits.h>, <sys/types.h>
97
99 Portions of this text are reprinted and reproduced in electronic form
100 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
101 -- Portable Operating System Interface (POSIX), The Open Group Base
102 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
103 Electrical and Electronics Engineers, Inc and The Open Group. In the
104 event of any discrepancy between this version and the original IEEE and
105 The Open Group Standard, the original IEEE and The Open Group Standard
106 is the referee document. The original Standard can be obtained online
107 at http://www.opengroup.org/unix/online.html .
108IEEE/The Open Group 2003 GETGRNAM(3P)