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Diffstat (limited to 'src/lib/common/string.c')
| -rw-r--r-- | src/lib/common/string.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/lib/common/string.c b/src/lib/common/string.c new file mode 100644 index 0000000..7c82653 --- /dev/null +++ b/src/lib/common/string.c @@ -0,0 +1,189 @@ +/* IBM_PROLOG_BEGIN_TAG */ +/* This is an automatically generated prolog. */ +/* */ +/* $Source: src/lib/common/string.c $ */ +/* */ +/* OpenPOWER OnChipController Project */ +/* */ +/* Contributors Listed Below - COPYRIGHT 2015 */ +/* [+] International Business Machines Corp. */ +/* */ +/* */ +/* Licensed under the Apache License, Version 2.0 (the "License"); */ +/* you may not use this file except in compliance with the License. */ +/* You may obtain a copy of the License at */ +/* */ +/* http://www.apache.org/licenses/LICENSE-2.0 */ +/* */ +/* Unless required by applicable law or agreed to in writing, software */ +/* distributed under the License is distributed on an "AS IS" BASIS, */ +/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or */ +/* implied. See the License for the specific language governing */ +/* permissions and limitations under the License. */ +/* */ +/* IBM_PROLOG_END_TAG */ +//----------------------------------------------------------------------------- +// *! (C) Copyright International Business Machines Corp. 2013 +// *! All Rights Reserved -- Property of IBM +// *! *** IBM Confidential *** +//----------------------------------------------------------------------------- + +/// \file string.c +/// \brief strlen(), strcmp() etc. functions + +#include "string.h" + +/// Compute the length of a string +/// +/// The strlen() function calculates the length of the string \a s, not +/// including the terminating \b '\0' character. The strlen() function +/// returns the number of characters in \a s. + +size_t +strlen(const char *s) +{ + const char *p = s; + + while (*p) { + p++; + } + + return p - s; +} + + +/// Compare two strings +/// +/// The strcmp() function compares the two strings \a s1 and \a s2. It +/// returns an integer less than, equal to, or greater than zero if \a s1 is +/// found, respectively, to be less than, to match, or be greater than \a s2. + +int +strcmp(const char* s1, const char* s2) +{ + int rc; + + if (s1 == s2) { + rc = 0; + } else { + while(*s1 && (*s1 == *s2)) { + s1++; + s2++; + } + rc = *((unsigned char *)s1) - *((unsigned char *)s2); + } + return rc; +} + + +/// Compare a portion of two strings +/// +/// The strncmp() function compares at most the first \n characters of the two +/// strings \a s1 and \a s2. It returns an integer less than, equal to, or +/// greater than zero if (the prefix of) \a s1 is found, respectively, to be +/// less than, to match, or be greater than (the prefix of) \a s2. + +int +strncmp(const char* s1, const char* s2, size_t n) +{ + int rc; + + if ((s1 == s2) || (n == 0)) { + rc = 0; + } else { + while(*s1 && (*s1 == *s2) && n--) { + s1++; + s2++; + } + rc = *((unsigned char *)s1) - *((unsigned char *)s2); + } + return rc; +} + + +/// Copy a string +/// +/// The strcpy() function copies the string pointed to by \a src (including +/// the terminating null character) to the array pointed to by \a dest. The +/// strings may not overlap, and the destination string \a dest must be large +/// enough to receive the copy. +/// +/// The strcpy() function return a pointer to the destination string \a dest. + +char * +strcpy(char *dest, const char *src) +{ + char *rv = dest; + + while (*src) { + *dest++ = *src++; + } + *dest = '\0'; + + return rv; +} + + +/// Safely copy all or part of a string +/// +/// The strncpy() function copies the string pointed to by \a src (including +/// the terminating null character) to the array pointed to by \a dest, except +/// that no more than \a n bytes of \a src are copied. This, if there is no +/// null byte among the first \a n bytes of \a src, the result will not be +/// null-terminated. In the case where the length of \a src is less than \a n, +/// the remainder of \a dest will be padded with null bytes. The strings may +/// not overlap. +/// +/// The strncpy() function return a pointer to the destination string \a dest. + +char * +strncpy(char *dest, const char *src, size_t n) +{ + char *rv = dest; + + while (*src && n--) { + *dest++ = *src++; + } + memset(dest, 0, n); + + return rv; +} + + +/// Compare two memory areas +/// +/// The memcmp() function compares the first \a n bytes of the memory areas \a +/// s1 and \a s2. It returns an integer less than, equal to, or greater than +/// zero if \a s1 is found, respectively, to be less than, to match, or be +/// greater than \a s2. +int +memcmp(const void* s1, const void* s2, size_t n) +{ + unsigned char *p1, *p2; + int rc; + + p1 = (unsigned char*) s1; + p2 = (unsigned char*) s2; + + if (s1 == s2) { + + rc = 0; + + } else { + + while (n && (*p1 == *p2)) { + n--; + p1++; + p2++; + } + + if (n == 0) { + rc = 0; + } else { + rc = (*p1 - *p2); + } + } + + return rc; +} + |
