diff options
Diffstat (limited to 'lib/strutil/strverscmp.c')
| -rw-r--r-- | lib/strutil/strverscmp.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/lib/strutil/strverscmp.c b/lib/strutil/strverscmp.c new file mode 100644 index 0000000..50f7f56 --- /dev/null +++ b/lib/strutil/strverscmp.c @@ -0,0 +1,158 @@ +/* + Compare strings while treating digits characters numerically. + + Copyright (C) 1997-2022 + Free Software Foundation, Inc. + + This file is part of the GNU C Library. + Contributed by Jean-François Bignolles <bignolle@ecoledoc.ibp.fr>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. + + This file is part of the Midnight Commander. + + The Midnight Commander is free software: you can redistribute it + and/or modify it under the terms of the GNU General Public License as + published by the Free Software Foundation, either version 3 of the License, + or (at your option) any later version. + + The Midnight Commander 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <config.h> + +#include <ctype.h> +#ifdef HAVE_STRVERSCMP +#include <string.h> +#endif /* HAVE_STRVERSCMP */ + +#include "lib/strutil.h" + +/*** global variables ****************************************************************************/ + +/*** file scope macro definitions ****************************************************************/ + +#ifndef HAVE_STRVERSCMP + +/* states: S_N: normal, S_I: comparing integral part, S_F: comparing + fractional parts, S_Z: idem but with leading Zeroes only */ +#define S_N 0x0 +#define S_I 0x3 +#define S_F 0x6 +#define S_Z 0x9 + +/* result_type: CMP: return diff; LEN: compare using len_diff/diff */ +#define CMP 2 +#define LEN 3 + +#endif /* HAVE_STRVERSCMP */ + +/*** file scope type declarations ****************************************************************/ + +/*** file scope variables ************************************************************************/ + +/* --------------------------------------------------------------------------------------------- */ +/*** file scope functions ************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ + +/* --------------------------------------------------------------------------------------------- */ +/*** public functions ****************************************************************************/ +/* --------------------------------------------------------------------------------------------- */ +/* Compare S1 and S2 as strings holding indices/version numbers, + returning less than, equal to or greater than zero if S1 is less than, + equal to or greater than S2 (for more info, see the texinfo doc). + */ +int +str_verscmp (const char *s1, const char *s2) +{ +#ifdef HAVE_STRVERSCMP + return strverscmp (s1, s2); + +#else /* HAVE_STRVERSCMP */ + const unsigned char *p1 = (const unsigned char *) s1; + const unsigned char *p2 = (const unsigned char *) s2; + unsigned char c1, c2; + int state; + int diff; + + /* *INDENT-OFF* */ + /* Symbol(s) 0 [1-9] others + Transition (10) 0 (01) d (00) x */ + static const unsigned char next_state[] = + { + /* state x d 0 */ + /* S_N */ S_N, S_I, S_Z, + /* S_I */ S_N, S_I, S_I, + /* S_F */ S_N, S_F, S_F, + /* S_Z */ S_N, S_F, S_Z + }; + + static const signed char result_type[] = + { + /* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */ + + /* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP, + /* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN, + /* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, + /* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP + }; + /* *INDENT-ON* */ + + if (p1 == p2) + return 0; + + c1 = *p1++; + c2 = *p2++; + /* Hint: '0' is a digit too. */ + state = S_N + ((c1 == '0') + (isdigit (c1) != 0)); + + while ((diff = c1 - c2) == 0) + { + if (c1 == '\0') + return diff; + + state = next_state[state]; + c1 = *p1++; + c2 = *p2++; + state += (c1 == '0') + (isdigit (c1) != 0); + } + + state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))]; + + switch (state) + { + case CMP: + return diff; + + case LEN: + while (isdigit (*p1++)) + if (!isdigit (*p2++)) + return 1; + + return isdigit (*p2) ? -1 : diff; + + default: + return state; + } +#endif /* HAVE_STRVERSCMP */ +} + +/* --------------------------------------------------------------------------------------------- */ |