diff options
Diffstat (limited to 'sysdeps/generic/strncat.c')
-rw-r--r-- | sysdeps/generic/strncat.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/generic/strncat.c b/sysdeps/generic/strncat.c new file mode 100644 index 0000000000..09463b36b8 --- /dev/null +++ b/sysdeps/generic/strncat.c @@ -0,0 +1,76 @@ +/* Copyright (C) 1991 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C 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. + +The GNU C 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 the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <ansidecl.h> +#include <string.h> +#include <memcopy.h> + +char * +DEFUN(strncat, (s1, s2, n), char *s1 AND CONST char *s2 AND size_t n) +{ + reg_char c; + char *s = s1; + + /* Find the end of S1. */ + do + c = *s1++; + while (c != '\0'); + + /* Make S1 point before next character, so we can increment + it while memory is read (wins on pipelined cpus). */ + s1 -= 2; + + if (n >= 4) + { + size_t n4 = n >> 2; + do + { + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + } while (--n4 > 0); + n &= 3; + } + + while (n > 0) + { + c = *s2++; + *++s1 = c; + if (c == '\0') + return s; + n--; + } + + if (c != '\0') + *++s1 = '\0'; + + return s; +} |