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libiconv v1.14

    1: /* Read symbolic links into a buffer without size limitation, relative to fd.
    2: 
    3:    Copyright (C) 2011 Free Software Foundation, Inc.
    4: 
    5:    This program is free software: you can redistribute it and/or modify
    6:    it under the terms of the GNU General Public License as published by
    7:    the Free Software Foundation; either version 3 of the License, or
    8:    (at your option) any later version.
    9: 
   10:    This program is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   13:    GNU General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU General Public License
   16:    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
   17: 
   18: /* Written by Paul Eggert, Bruno Haible, and Jim Meyering.  */
   19: 
   20: #ifndef _GL_CAREADLINKAT_H
   21: #define _GL_CAREADLINKAT_H
   22: 
   23: #include <fcntl.h>
   24: #include <unistd.h>
   25: 
   26: struct allocator;
   27: 
   28: /* Assuming the current directory is FD, get the symbolic link value
   29:    of FILENAME as a null-terminated string and put it into a buffer.
   30:    If FD is AT_FDCWD, FILENAME is interpreted relative to the current
   31:    working directory, as in openat.
   32: 
   33:    If the link is small enough to fit into BUFFER put it there.
   34:    BUFFER's size is BUFFER_SIZE, and BUFFER can be null
   35:    if BUFFER_SIZE is zero.
   36: 
   37:    If the link is not small, put it into a dynamically allocated
   38:    buffer managed by ALLOC.  It is the caller's responsibility to free
   39:    the returned value if it is nonnull and is not BUFFER.
   40: 
   41:    The PREADLINKAT function specifies how to read links.  It operates
   42:    like POSIX readlinkat()
   43:    <http://pubs.opengroup.org/onlinepubs/9699919799/functions/readlink.html>
   44:    but can assume that its first argument is the same as FD.
   45: 
   46:    If successful, return the buffer address; otherwise return NULL and
   47:    set errno.  */
   48: 
   49: char *careadlinkat (int fd, char const *filename,
   50:                     char *buffer, size_t buffer_size,
   51:                     struct allocator const *alloc,
   52:                     ssize_t (*preadlinkat) (int, char const *,
   53:                                             char *, size_t));
   54: 
   55: /* Suitable values for careadlinkat's FD and PREADLINKAT arguments,
   56:    when doing a plain readlink:
   57:    Pass FD = AT_FDCWD and PREADLINKAT = careadlinkatcwd.  */
   58: #if HAVE_READLINKAT
   59: /* AT_FDCWD is declared in <fcntl.h>.  */
   60: #else
   61: /* Define AT_FDCWD independently, so that the careadlinkat module does
   62:    not depend on the fcntl-h module.  The value does not matter, since
   63:    careadlinkatcwd ignores it, but we might as well use the same value
   64:    as fcntl-h.  */
   65: # ifndef AT_FDCWD
   66: #  define AT_FDCWD (-3041965)
   67: # endif
   68: #endif
   69: ssize_t careadlinkatcwd (int fd, char const *filename,
   70:                          char *buffer, size_t buffer_size);
   71: 
   72: #endif /* _GL_CAREADLINKAT_H */