diff options
Diffstat (limited to 'debug/gets_chk.c')
-rw-r--r-- | debug/gets_chk.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/debug/gets_chk.c b/debug/gets_chk.c new file mode 100644 index 0000000000..3715a39672 --- /dev/null +++ b/debug/gets_chk.c @@ -0,0 +1,77 @@ +/* Copyright (C) 1993, 1996, 1997, 1998, 2002, 2003, 2004 + Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. + + As a special exception, if you link the code in this file with + files compiled with a GNU compiler to produce an executable, + that does not cause the resulting executable to be covered by + the GNU Lesser General Public License. This exception does not + however invalidate any other reasons why the executable file + might be covered by the GNU Lesser General Public License. + This exception applies to code released by its copyright holders + in files containing the exception. */ + +#include "../libio/libioP.h" +#include <limits.h> + +char * +__gets_chk (char *buf, size_t size) +{ + _IO_size_t count; + int ch; + char *retval; + + if (size == 0) + __chk_fail (); + + _IO_acquire_lock (_IO_stdin); + ch = _IO_getc_unlocked (_IO_stdin); + if (ch == EOF) + { + retval = NULL; + goto unlock_return; + } + if (ch == '\n') + count = 0; + else + { + /* This is very tricky since a file descriptor may be in the + non-blocking mode. The error flag doesn't mean much in this + case. We return an error only when there is a new error. */ + int old_error = _IO_stdin->_IO_file_flags & _IO_ERR_SEEN; + _IO_stdin->_IO_file_flags &= ~_IO_ERR_SEEN; + buf[0] = (char) ch; + count = INTUSE(_IO_getline) (_IO_stdin, buf + 1, size - 1, '\n', 0) + 1; + if (_IO_stdin->_IO_file_flags & _IO_ERR_SEEN) + { + retval = NULL; + goto unlock_return; + } + else + _IO_stdin->_IO_file_flags |= old_error; + } + if (count >= size) + __chk_fail (); + buf[count] = 0; + retval = buf; +unlock_return: + _IO_release_lock (_IO_stdin); + return retval; +} + +link_warning (__gets_chk, "the `gets' function is dangerous and should not be used.") |