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Diffstat (limited to 'nuttx/libc/string/lib_checkbase.c')
-rw-r--r-- | nuttx/libc/string/lib_checkbase.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/nuttx/libc/string/lib_checkbase.c b/nuttx/libc/string/lib_checkbase.c new file mode 100644 index 000000000..32ae58dca --- /dev/null +++ b/nuttx/libc/string/lib_checkbase.c @@ -0,0 +1,115 @@ +/**************************************************************************** + * libc/string/lib_checkbase.c + * + * Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 NuttX 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. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <string.h> +#include <ctype.h> + +#include "lib_internal.h" + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: lib_checkbase + * + * Description: + * This is part of the strol() family implementation. This function checks + * the initial part of a string to see if it can determine the numeric + * base that is represented. + * + * Assumptions: + * *ptr points to the first, non-whitespace character in the string. + * + ****************************************************************************/ + +int lib_checkbase(int base, const char **pptr) +{ + const char *ptr = *pptr; + + /* Check for unspecified base */ + + if (!base) + { + /* Assume base 10 */ + + base = 10; + + /* Check for leading '0' - that would signify octal or hex (or binary) */ + + if (*ptr == '0') + { + /* Assume octal */ + + base = 8; + ptr++; + + /* Check for hexidecimal */ + + if ((*ptr == 'X' || *ptr == 'x') && + lib_isbasedigit(ptr[1], 16, NULL)) + { + base = 16; + ptr++; + } + } + } + + /* If it a hexidecimal representation, than discard any leading "0X" or "0x" */ + + else if (base == 16) + { + if (ptr[0] == '0' && (ptr[1] == 'X' || ptr[1] == 'x')) + { + ptr += 2; + } + } + + /* Return the updated pointer and base */ + + *pptr = ptr; + return base; +} + |