On Fri, Aug 05, 2011 at 09:19:43AM -0400, Dan McGee wrote:
On Thu, Aug 4, 2011 at 9:01 AM, Dave Reisner <d@falconindy.com> wrote:
So it occurs to me that while it's all well and good to have a portable package cache cleaner, it's no good at all if it all hinges on a GNU sort flag (-V) which poorly approximates what vercmp does. Would we have room for sort tool that implements alpm_pkg_vercmp? A simple implementation could be as easy as the below... I think this would get a lot of mileage out of the AUR/pacman wrapper crowd.
thoughts?
Looks like this just takes a list of newline-separated versions on stdin then? Seems pretty reasonable, although argument support would be good as well. I'm also wondering whether supporting `pacman -Q` style input would be good as well (with package names and version numbers); thus it would be a smart sort going first by package name, but then interpreting the second component as a version rather than string.
#include <alpm.h> #include <stdio.h> #include <stdlib.h> #include <string.h>
#define MAXLEN 4096 If the tool is new, I'd prefer to avoid any buffer/line length restrictions.
int vercmp(const void *p1, const void *p2) { return alpm_pkg_vercmp(*(const char**)p1, *(const char**)p2); }
int main(void) {
char **pkglist = NULL; char *pkg; This is a tad nitpicky, but since we never load actual package objects, might be wise to call these namelist and name instead. char buf[MAXLEN + 1]; fgets reads at most n-1 characters and always null-terminates; no need for the extra byte. int i, pkgcount = 0; offsets should use size_t.
while (fgets(buf, MAXLEN + 1, stdin)) { If you heed my advice above the +1 will have to go away here. pkg = strndup(buf, MAXLEN); You already know buf is well-bounded, correct? strdup() is sufficient. *(pkg + strlen(pkg) - 1) = '\0'; I'm going to throw a CRLF file at this to test. :) pkglist = realloc(pkglist, ++pkgcount * sizeof(*pkglist)); Would be best to not reallocate every iteration, but instead do smart
coding style, brace on next line. progression- start with something small/sane like 4, then double it each realloc. Also, the ++ works, but I'm not a fan of it inline like this.
*(pkglist + pkgcount - 1) = pkg; If pkglist is a * instead of a **, I think you will be able to do something like pkglist[pkgcount - 1] = pkg; instead. That also simplifies the dereferences needed in the printf() below as you can just do pkglist[i] instead. This is all untested, but I'm basing it roughly off what I ended up doing for the files array stuff in be_local.c. }
qsort(pkglist, pkgcount, sizeof(char*), vercmp); char(space)*, style rules.
for (i = 0; i < pkgcount; i++) { printf("%s\n", *(pkglist + i)); free(*(pkglist + i)); } if (pkgcount > 0) { free(pkglist); }
return 0; }
Of course. All lovely suggestions which will be taken into account. This was just a proof of concept to get feedback before I spend any time on it. Since it seems like I'm not crazy for thinking that this is something useful, I'll clean it up to our standards. d