diff options
Diffstat (limited to 'nuttx/lib/lib_ungetc.c')
-rw-r--r-- | nuttx/lib/lib_ungetc.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/nuttx/lib/lib_ungetc.c b/nuttx/lib/lib_ungetc.c new file mode 100644 index 0000000000..45cde1efc9 --- /dev/null +++ b/nuttx/lib/lib_ungetc.c @@ -0,0 +1,124 @@ +/************************************************************ + * lib_ungetc.c + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name Gregory Nutt nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ************************************************************/ + +/************************************************************ + * Compilation Switches + ************************************************************/ + +/************************************************************ + * Included Files + ************************************************************/ + +#include <nuttx/config.h> + +#if CONFIG_NFILE_STREAMS > 0 + +#include <stdio.h> +#include <errno.h> +#include <nuttx/fs.h> +#include "lib_internal.h" + +/************************************************************ + * Definitions + ************************************************************/ + +/************************************************************ + * Private Type Declarations + ************************************************************/ + +/************************************************************ + * Private Function Prototypes + ************************************************************/ + +/************************************************************ + * Global Function Prototypes + ************************************************************/ + +/********************************************************** + * Global Constant Data + **********************************************************/ + +/************************************************************ + * Global Variables + ************************************************************/ + +/********************************************************** + * Private Constant Data + **********************************************************/ + +/************************************************************ + * Private Variables + **********************************************************/ + +/************************************************************ + * Global Functions + **********************************************************/ + +/************************************************************ + * fgetc + **********************************************************/ + +int ungetc(int c, FILE *stream) +{ +#if CONFIG_NUNGET_CHARS > 0 + int nungotten; +#endif + + /* Stream must be open for read access */ + + if ((stream && stream->fs_filedes < 0) || + ((stream->fs_oflags & O_RDOK) == 0)) + { + *get_errno_ptr() = EBADF; + return EOF; + } + +#if CONFIG_NUNGET_CHARS > 0 + nungotten = stream->fs_nungotten; + if (stream->fs_nungotten < CONFIG_NUNGET_CHARS) + { + stream->fs_ungotten[nungotten] = c; + stream->fs_nungotten = nungotten + 1; + return c; + } + else +#endif + { + *get_errno_ptr() = ENOMEM; + return EOF; + } +} + +#endif /* CONFIG_NFILE_STREAMS */ |