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Diffstat (limited to 'nuttx/libc/string/lib_strtokr.c')
-rw-r--r-- | nuttx/libc/string/lib_strtokr.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/nuttx/libc/string/lib_strtokr.c b/nuttx/libc/string/lib_strtokr.c new file mode 100644 index 000000000..c7845be64 --- /dev/null +++ b/nuttx/libc/string/lib_strtokr.c @@ -0,0 +1,157 @@ +/**************************************************************************** + * libc/string/lib_strtokr.c + * + * Copyright (C) 2007, 2008, 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 <string.h> + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: strtok_r + * + * Description: + * The strtok_r() function is a reentrant version strtok(). + * Like strtok(), it parses a string into a sequence of + * tokens. On the first call to strtok() the string to be + * parsed should be specified in 'str'. In each subsequent + * call that should parse the same string, 'str' should be + * NULL. + * + * The 'saveptr' argument is a pointer to a char * + * variable that is used internally by strtok_r() in + * order to maintain context between successive calls + * that parse the same string. + * + * On the first call to strtok_r(), 'str' should point to the + * string to be parsed, and the value of 'saveptr' is + * ignored. In subsequent calls, 'str' should be NULL, and + * saveptr should be unchanged since the previous call. + * + * The 'delim' argument specifies a set of characters that + * delimit the tokens in the parsed string. The caller + * may specify different strings in delim in successive + * calls that parse the same string. + * + * Each call to strtok_r() returns a pointer to a null- + * terminated string containing the next token. This + * string does not include the delimiting character. If + * no more tokens are found, strtok_r() returns NULL. + * + * A sequence of two or more contiguous delimiter + * characters in the parsed string is considered to be a + * single delimiter. Delimiter characters at the start or + * end of the string are ignored. The tokens returned by + * strtok() are always non-empty strings. + * + * Return + * strtok_r() returns a pointer to the next token, or NULL + * if there are no more tokens. + * + ****************************************************************************/ + +FAR char *strtok_r(FAR char *str, FAR const char *delim, FAR char **saveptr) +{ + char *pbegin; + char *pend = NULL; + + /* Decide if we are starting a new string or continuing from + * the point we left off. + */ + + if (str) + { + pbegin = str; + } + else if (saveptr && *saveptr) + { + pbegin = *saveptr; + } + else + { + return NULL; + } + + /* Find the beginning of the next token */ + + for (; + *pbegin && strchr(delim, *pbegin) != NULL; + pbegin++); + + /* If we are at the end of the string with nothing + * but delimiters found, then return NULL. + */ + + if (!*pbegin) + { + return NULL; + } + + /* Find the end of the token */ + + for (pend = pbegin + 1; + *pend && strchr(delim, *pend) == NULL; + pend++); + + + /* pend either points to the end of the string or to + * the first delimiter after the string. + */ + + if (*pend) + { + /* Turn the delimiter into a null terminator */ + + *pend++ = '\0'; + } + + /* Save the pointer where we left off and return the + * beginning of the token. + */ + + if (saveptr) + { + *saveptr = pend; + } + return pbegin; +} |