lookup.subproj/getgrouplist.3

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  28 .\"     @(#)getgrouplist.3      8.1 (Berkeley) 6/9/93
  29 .\" $FreeBSD: src/lib/libc/gen/getgrouplist.3,v 1.9 2007/01/09 00:27:53 imp Exp $
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  31 .Dd June 9, 1993
  32 .Dt GETGROUPLIST 3
  33 .Os
  34 .Sh NAME
  35 .Nm getgrouplist
  36 .Nd calculate group access list
  37 .Sh LIBRARY
  38 .Lb libc
  39 .Sh SYNOPSIS
  40 .In unistd.h
  41 .Ft int
  42 .Fn getgrouplist "const char *name" "int basegid" "int *groups" "int *ngroups"
  43 .\".Fn getgrouplist "const char *name" "gid_t basegid" "gid_t *groups" "int *ngroups"
  44 .Sh DESCRIPTION
  45 The
  46 .Fn getgrouplist
  47 function reads through the group file and calculates
  48 the group access list for the user specified in
  49 .Fa name .
  50 The
  51 .Fa basegid
  52 is automatically included in the groups list.
  53 Typically this value is given as
  54 the group number from the password file.
  55 .Pp
  56 The resulting group list is returned in the array pointed to by
  57 .Fa groups .
  58 The caller specifies the size of the
  59 .Fa groups
  60 array in the integer pointed to by
  61 .Fa ngroups ;
  62 the actual number of groups found is returned in
  63 .Fa ngroups .
  64 .Sh RETURN VALUES
  65 The
  66 .Fn getgrouplist
  67 function
  68 returns \-1 if the size of the group list is too small to
  69 hold all the user's groups.
  70 Here, the group array will be filled with as many groups as will fit.
  71 .Sh FILES
  72 .Bl -tag -width /etc/group -compact
  73 .It Pa /etc/group
  74 group membership list
  75 .El
  76 .Sh SEE ALSO
  77 .Xr setgroups 2 ,
  78 .Xr initgroups 3
  79 .Sh HISTORY
  80 The
  81 .Fn getgrouplist
  82 function first appeared in
  83 .Bx 4.4 .
  84 .Sh BUGS
  85 The
  86 .Fn getgrouplist
  87 function
  88 uses the routines based on
  89 .Xr getgrent 3 .
  90 If the invoking program uses any of these routines,
  91 the group structure will
  92 be overwritten in the call to
  93 .Fn getgrouplist .