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authorDan McGee <dan@archlinux.org>2010-04-05 14:56:32 -0500
committerDan McGee <dan@archlinux.org>2010-05-04 23:32:13 -0500
commit2a6f3f06528149200e4fc8996c0c1e6d2bfa5480 (patch)
treeaac905d8cdaf36c58f3c6365f3a2089ed3e98617 /lib/libalpm/version.c
parent8a6bbed98e11be3f619ef31e9e753d31081d11ee (diff)
downloadpacman-2a6f3f06528149200e4fc8996c0c1e6d2bfa5480.tar.xz
Move vercmp code into a separate file
This will facilitate using this object file on its own in the vercmp tool which will be done in a future commit. The net impact on the generated binaries should not be noticeable after this commit. Signed-off-by: Dan McGee <dan@archlinux.org>
Diffstat (limited to 'lib/libalpm/version.c')
-rw-r--r--lib/libalpm/version.c198
1 files changed, 198 insertions, 0 deletions
diff --git a/lib/libalpm/version.c b/lib/libalpm/version.c
new file mode 100644
index 00000000..1c838f41
--- /dev/null
+++ b/lib/libalpm/version.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2006-2010 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 "log.h"
+#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;
+
+ ALPM_LOG_FUNC;
+
+ /* 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: */