/* * Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org> * * This program 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 2 of the License, or * (at your option) any later version. * * This program 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 <string.h> #include <ctype.h> /* libalpm */ #include "util.h" /** Compare two version strings and determine which one is 'newer'. * Returns a value comparable to the way strcmp works. Returns 1 * if a is newer than b, 0 if a and b are the same version, or -1 * if b is newer than a. * * This function has been adopted from the rpmvercmp function located * at lib/rpmvercmp.c, and was most recently updated against rpm * version 4.4.2.3. Small modifications have been made to make it more * consistent with the libalpm coding style. * * Keep in mind that the pkgrel is only compared if it is available * on both versions handed to this function. For example, comparing * 1.5-1 and 1.5 will yield 0; comparing 1.5-1 and 1.5-2 will yield * -1 as expected. This is mainly for supporting versioned dependencies * that do not include the pkgrel. */ int SYMEXPORT alpm_pkg_vercmp(const char *a, const char *b) { char oldch1, oldch2; char *str1, *str2; char *ptr1, *ptr2; char *one, *two; int rc; int isnum; int ret = 0; /* libalpm added code. ensure our strings are not null */ if(!a) { if(!b) return(0); return(-1); } if(!b) return(1); /* easy comparison to see if versions are identical */ if(strcmp(a, b) == 0) return(0); str1 = strdup(a); str2 = strdup(b); one = str1; two = str2; /* loop through each version segment of str1 and str2 and compare them */ while(*one && *two) { while(*one && !isalnum((int)*one)) one++; while(*two && !isalnum((int)*two)) two++; /* If we ran to the end of either, we are finished with the loop */ if(!(*one && *two)) break; ptr1 = one; ptr2 = two; /* grab first completely alpha or completely numeric segment */ /* leave one and two pointing to the start of the alpha or numeric */ /* segment and walk ptr1 and ptr2 to end of segment */ if(isdigit((int)*ptr1)) { while(*ptr1 && isdigit((int)*ptr1)) ptr1++; while(*ptr2 && isdigit((int)*ptr2)) ptr2++; isnum = 1; } else { while(*ptr1 && isalpha((int)*ptr1)) ptr1++; while(*ptr2 && isalpha((int)*ptr2)) ptr2++; isnum = 0; } /* save character at the end of the alpha or numeric segment */ /* so that they can be restored after the comparison */ oldch1 = *ptr1; *ptr1 = '\0'; oldch2 = *ptr2; *ptr2 = '\0'; /* this cannot happen, as we previously tested to make sure that */ /* the first string has a non-null segment */ if (one == ptr1) { ret = -1; /* arbitrary */ goto cleanup; } /* take care of the case where the two version segments are */ /* different types: one numeric, the other alpha (i.e. empty) */ /* numeric segments are always newer than alpha segments */ /* XXX See patch #60884 (and details) from bugzilla #50977. */ if (two == ptr2) { ret = isnum ? 1 : -1; goto cleanup; } if (isnum) { /* this used to be done by converting the digit segments */ /* to ints using atoi() - it's changed because long */ /* digit segments can overflow an int - this should fix that. */ /* throw away any leading zeros - it's a number, right? */ while (*one == '0') one++; while (*two == '0') two++; /* whichever number has more digits wins */ if (strlen(one) > strlen(two)) { ret = 1; goto cleanup; } if (strlen(two) > strlen(one)) { ret = -1; goto cleanup; } } /* strcmp will return which one is greater - even if the two */ /* segments are alpha or if they are numeric. don't return */ /* if they are equal because there might be more segments to */ /* compare */ rc = strcmp(one, two); if (rc) { ret = rc < 1 ? -1 : 1; goto cleanup; } /* restore character that was replaced by null above */ *ptr1 = oldch1; one = ptr1; *ptr2 = oldch2; two = ptr2; /* libalpm added code. check if version strings have hit the pkgrel * portion. depending on which strings have hit, take correct action. * this is all based on the premise that we only have one dash in * the version string, and it separates pkgver from pkgrel. */ if(*ptr1 == '-' && *ptr2 == '-') { /* no-op, continue comparing since we are equivalent throughout */ } else if(*ptr1 == '-') { /* ptr1 has hit the pkgrel and ptr2 has not. continue version * comparison after stripping the pkgrel from ptr1. */ *ptr1 = '\0'; } else if(*ptr2 == '-') { /* ptr2 has hit the pkgrel and ptr1 has not. continue version * comparison after stripping the pkgrel from ptr2. */ *ptr2 = '\0'; } } /* this catches the case where all numeric and alpha segments have */ /* compared identically but the segment separating characters were */ /* different */ if ((!*one) && (!*two)) { ret = 0; goto cleanup; } /* the final showdown. we never want a remaining alpha string to * beat an empty string. the logic is a bit weird, but: * - if one is empty and two is not an alpha, two is newer. * - if one is an alpha, two is newer. * - otherwise one is newer. * */ if ( ( !*one && !isalpha((int)*two) ) || isalpha((int)*one) ) { ret = -1; } else { ret = 1; } cleanup: free(str1); free(str2); return(ret); } /* vim: set ts=2 sw=2 noet: */