| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Compare version numbers using the Debian algorithm |
| 4 | * |
| 5 | * (c) 2007 Straylight/Edgeware |
| 6 | */ |
| 7 | |
| 8 | /*----- Licensing notice --------------------------------------------------* |
| 9 | * |
| 10 | * This file is part of the mLib utilities library. |
| 11 | * |
| 12 | * mLib is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU Library General Public License as |
| 14 | * published by the Free Software Foundation; either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * mLib is distributed in the hope that it will be useful, |
| 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | * GNU Library General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU Library General Public |
| 23 | * License along with mLib; if not, write to the Free |
| 24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 25 | * MA 02111-1307, USA. |
| 26 | */ |
| 27 | |
| 28 | /*----- Header files ------------------------------------------------------*/ |
| 29 | |
| 30 | #include <ctype.h> |
| 31 | #include <string.h> |
| 32 | |
| 33 | #include "macros.h" |
| 34 | #include "versioncmp.h" |
| 35 | |
| 36 | /*----- Main code ---------------------------------------------------------*/ |
| 37 | |
| 38 | /* --- @versioncmp@ --- * |
| 39 | * |
| 40 | * Arguments: @const char *va, *vb@ = two version strings |
| 41 | * |
| 42 | * Returns: Less than, equal to, or greater than zero, according to |
| 43 | * whether @va@ is less than, equal to, or greater than @vb@. |
| 44 | * |
| 45 | * Use: Compares version number strings. |
| 46 | * |
| 47 | * The algorithm is an extension of the Debian version |
| 48 | * comparison algorithm. A version number consists of three |
| 49 | * components: |
| 50 | * |
| 51 | * [EPOCH :] MAIN [- SUB] |
| 52 | * |
| 53 | * The MAIN part may contain colons or hyphens if there is an |
| 54 | * EPOCH or SUB, respectively. Version strings are compared |
| 55 | * componentwise: first epochs, then main parts, and finally |
| 56 | * subparts. |
| 57 | * |
| 58 | * The component comparison is done as follows. First, the |
| 59 | * initial subsequence of nondigit characters is extracted from |
| 60 | * each string, and these are compared lexicographically, using |
| 61 | * ASCII ordering, except that letters precede non-letters. If |
| 62 | * both are the same, an initial sequence of digits is extracted |
| 63 | * from the remaining parts of the version strings, and these |
| 64 | * are compared numerically (an empty sequence being considered |
| 65 | * to have the value zero). This process is repeated until we |
| 66 | * have a winner or until both strings are exhausted. |
| 67 | */ |
| 68 | |
| 69 | struct vinfo { |
| 70 | const char *e, *el; |
| 71 | const char *m, *ml; |
| 72 | const char *s, *sl; |
| 73 | }; |
| 74 | |
| 75 | static int vint(const char **vv, const char *vl) |
| 76 | { |
| 77 | int n = 0; |
| 78 | const char *v = *vv; |
| 79 | int ch; |
| 80 | |
| 81 | while (v < vl) { |
| 82 | ch = *v; |
| 83 | if (!ISDIGIT(ch)) |
| 84 | break; |
| 85 | v++; |
| 86 | n = n * 10 + (ch - '0'); |
| 87 | } |
| 88 | *vv = v; |
| 89 | return (n); |
| 90 | } |
| 91 | |
| 92 | static const char *vchr(const char **vv, const char *vl) |
| 93 | { |
| 94 | const char *v = *vv; |
| 95 | const char *b = v; |
| 96 | int ch; |
| 97 | |
| 98 | while (v < vl) { |
| 99 | ch = *v; |
| 100 | if (ISDIGIT(ch)) |
| 101 | break; |
| 102 | v++; |
| 103 | } |
| 104 | *vv = v; |
| 105 | return (b); |
| 106 | } |
| 107 | |
| 108 | #define CMP(x, y) ((x) < (y) ? -1 : +1) |
| 109 | |
| 110 | static int vcmp(const char *va, const char *val, |
| 111 | const char *vb, const char *vbl) |
| 112 | { |
| 113 | const char *pa, *pb; |
| 114 | int ia, ib; |
| 115 | |
| 116 | for (;;) { |
| 117 | |
| 118 | /* --- See if we're done --- */ |
| 119 | |
| 120 | if (va == val && vb == vbl) |
| 121 | return (0); |
| 122 | |
| 123 | /* --- Compare nondigit portions --- */ |
| 124 | |
| 125 | pa = vchr(&va, val); pb = vchr(&vb, vbl); |
| 126 | for (;;) { |
| 127 | if (pa == va) ia = 1; |
| 128 | else if (ISALPHA(*pa)) ia = 2; |
| 129 | else if (*pa == '~') ia = 0; |
| 130 | else ia = 3; |
| 131 | |
| 132 | if (pb == vb) ib = 1; |
| 133 | else if (ISALPHA(*pb)) ib = 2; |
| 134 | else if (*pb == '~') ib = 0; |
| 135 | else ib = 3; |
| 136 | |
| 137 | if (ia != ib) return (CMP(ia, ib)); |
| 138 | else if (pa == va && pb == vb) break; |
| 139 | else if (*pa != *pb) return (CMP(*pa, *pb)); |
| 140 | pa++; pb++; |
| 141 | } |
| 142 | |
| 143 | /* --- Compare digit portions --- */ |
| 144 | |
| 145 | ia = vint(&va, val); ib = vint(&vb, vbl); |
| 146 | if (ia != ib) return (CMP(ia, ib)); |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | static void vsplit(const char *v, struct vinfo *vi) |
| 151 | { |
| 152 | const char *p; |
| 153 | size_t n; |
| 154 | |
| 155 | if ((p = strchr(v, ':')) == 0) |
| 156 | vi->e = vi->el = 0; |
| 157 | else { |
| 158 | vi->e = v; |
| 159 | vi->el = p; |
| 160 | v = p + 1; |
| 161 | } |
| 162 | |
| 163 | n = strlen(v); |
| 164 | if ((p = strrchr(v, '-')) == 0) |
| 165 | vi->s = vi->sl = 0; |
| 166 | else { |
| 167 | vi->s = p + 1; |
| 168 | vi->sl = v + n; |
| 169 | n = p - v; |
| 170 | } |
| 171 | |
| 172 | vi->m = v; |
| 173 | vi->ml = v + n; |
| 174 | } |
| 175 | |
| 176 | int versioncmp(const char *va, const char *vb) |
| 177 | { |
| 178 | struct vinfo via, vib; |
| 179 | int rc; |
| 180 | |
| 181 | vsplit(va, &via); vsplit(vb, &vib); |
| 182 | if ((rc = vcmp(via.e, via.el, vib.e, vib.el)) != 0 || |
| 183 | (rc = vcmp(via.m, via.ml, vib.m, vib.ml)) != 0 || |
| 184 | (rc = vcmp(via.s, via.sl, vib.s, vib.sl)) != 0) |
| 185 | return (rc); |
| 186 | return (0); |
| 187 | } |
| 188 | |
| 189 | /*----- That's all, folks -------------------------------------------------*/ |