1 /*
2 * This code is taken from the RPM package manager.
3 *
4 * RPM is Copyright (c) 1998 by Red Hat Software, Inc.,
5 * and may be distributed under the terms of the GPL and LGPL.
6 * See http://rpm.org/gitweb?p=rpm.git;a=blob_plain;f=COPYING;hb=HEAD
7 *
8 * The code should follow upstream as closely as possible.
9 * See http://rpm.org/gitweb?p=rpm.git;a=blob_plain;f=lib/rpmvercmp.c;hb=HEAD
10 *
11 * Currently the only difference as a policy is that upstream uses C99
12 * features and pkg-config does not require a C99 compiler yet.
13 */
14
15 #ifdef HAVE_CONFIG_H
16 #include "config.h"
17 #endif
18
19 #include <string.h>
20 #include <ctype.h>
21 #include <stdlib.h>
22
23 /* macros to help code look more like upstream */
24 #define rstreq(a, b) (strcmp(a, b) == 0)
25 #define risalnum(c) isalnum((char)(c))
26 #define risdigit(c) isdigit((char)(c))
27 #define risalpha(c) isalpha((char)(c))
28
29 int rmpvercmp_impl(const char *a, const char *b, char *buf1, char *buf2);
30
31 /* compare alpha and numeric segments of two versions */
32 /* return 1: a is newer than b */
33 /* 0: a and b are the same version */
34 /* -1: b is newer than a */
rpmvercmp(const char * a,const char * b)35 int rpmvercmp(const char * a, const char * b)
36 {
37 /* easy comparison to see if versions are identical */
38 if (rstreq(a, b)) return 0;
39
40 char *buf1 = malloc(strlen(a) + 1);
41 char *buf2 = malloc(strlen(b) + 1);
42
43 if (!buf1 || !buf2) return 0; // arbitrary
44
45 int r = rmpvercmp_impl(a, b, buf1, buf2);
46
47 free(buf1);
48 free(buf2);
49
50 return r;
51 }
52
rmpvercmp_impl(const char * a,const char * b,char * str1,char * str2)53 int rmpvercmp_impl(const char *a, const char *b, char *str1, char *str2) {
54 char oldch1, oldch2;
55 char * one, * two;
56 int rc;
57 int isnum;
58
59 strcpy(str1, a);
60 strcpy(str2, b);
61
62 one = str1;
63 two = str2;
64
65 /* loop through each version segment of str1 and str2 and compare them */
66 while (*one && *two) {
67 while (*one && !risalnum(*one)) one++;
68 while (*two && !risalnum(*two)) two++;
69
70 /* If we ran to the end of either, we are finished with the loop */
71 if (!(*one && *two)) break;
72
73 str1 = one;
74 str2 = two;
75
76 /* grab first completely alpha or completely numeric segment */
77 /* leave one and two pointing to the start of the alpha or numeric */
78 /* segment and walk str1 and str2 to end of segment */
79 if (risdigit(*str1)) {
80 while (*str1 && risdigit(*str1)) str1++;
81 while (*str2 && risdigit(*str2)) str2++;
82 isnum = 1;
83 } else {
84 while (*str1 && risalpha(*str1)) str1++;
85 while (*str2 && risalpha(*str2)) str2++;
86 isnum = 0;
87 }
88
89 /* save character at the end of the alpha or numeric segment */
90 /* so that they can be restored after the comparison */
91 oldch1 = *str1;
92 *str1 = '\0';
93 oldch2 = *str2;
94 *str2 = '\0';
95
96 /* this cannot happen, as we previously tested to make sure that */
97 /* the first string has a non-null segment */
98 if (one == str1) return -1; /* arbitrary */
99
100 /* take care of the case where the two version segments are */
101 /* different types: one numeric, the other alpha (i.e. empty) */
102 /* numeric segments are always newer than alpha segments */
103 /* XXX See patch #60884 (and details) from bugzilla #50977. */
104 if (two == str2) return (isnum ? 1 : -1);
105
106 if (isnum) {
107 /* this used to be done by converting the digit segments */
108 /* to ints using atoi() - it's changed because long */
109 /* digit segments can overflow an int - this should fix that. */
110
111 /* throw away any leading zeros - it's a number, right? */
112 while (*one == '0') one++;
113 while (*two == '0') two++;
114
115 /* whichever number has more digits wins */
116 if (strlen(one) > strlen(two)) return 1;
117 if (strlen(two) > strlen(one)) return -1;
118 }
119
120 /* strcmp will return which one is greater - even if the two */
121 /* segments are alpha or if they are numeric. don't return */
122 /* if they are equal because there might be more segments to */
123 /* compare */
124 rc = strcmp(one, two);
125 if (rc) return (rc < 1 ? -1 : 1);
126
127 /* restore character that was replaced by null above */
128 *str1 = oldch1;
129 one = str1;
130 *str2 = oldch2;
131 two = str2;
132 }
133
134 /* this catches the case where all numeric and alpha segments have */
135 /* compared identically but the segment sepparating characters were */
136 /* different */
137 if ((!*one) && (!*two)) return 0;
138
139 /* whichever version still has characters left over wins */
140 if (!*one) return -1; else return 1;
141 }
142