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Diffstat (limited to 'strings/memcmp.c')
-rw-r--r-- | strings/memcmp.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/strings/memcmp.c b/strings/memcmp.c new file mode 100644 index 00000000000..1bb8deaeac0 --- /dev/null +++ b/strings/memcmp.c @@ -0,0 +1,46 @@ +/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later version. + + This 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with this library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, + MA 02111-1307, USA */ + +/* memcmp(lhs, rhs, len) + compares the two memory areas lhs[0..len-1] ?? rhs[0..len-1]. It + returns an integer less than, equal to, or greater than 0 according + as lhs[-] is lexicographically less than, equal to, or greater than + rhs[-]. Note that this is not at all the same as bcmp, which tells + you *where* the difference is but not what. + + Note: suppose we have int x, y; then memcmp(&x, &y, sizeof x) need + not bear any relation to x-y. This is because byte order is machine + dependent, and also, some machines have integer representations that + are shorter than a machine word and two equal integers might have + different values in the spare bits. On a ones complement machine, + -0 == 0, but the bit patterns are different. +*/ + +#include "strings.h" + +#if !defined(HAVE_MEMCPY) + +int memcmp(lhs, rhs, len) + register char *lhs, *rhs; + register int len; +{ + while (--len >= 0) + if (*lhs++ != *rhs++) return (uchar) lhs[-1] - (uchar) rhs[-1]; + return 0; +} + +#endif |