[pacman-dev] Pacman Hooks
Dan McGee
dpmcgee at gmail.com
Sat Jan 29 13:52:47 EST 2011
On Sat, Jan 29, 2011 at 8:36 AM, Sascha Kruse <knopwob at googlemail.com> wrote:
> Hello,
>
> I used this https://wiki.archlinux.org/index.php/User:Allan/Pacman_Hooks
> as a Project to learn c (so keep that in mind when you criticize the
> patch :-) ).
Welcome!
> Anyway, here's an example config file:
>
> /etc/pacman.d/hooks.conf:
> [testhook]
>
> Package = lynx nano
> Package = vim
>
> When = PreRemove
>
> [fonts]
> File = usr/share/fonts/*
> When = PostUpgrade
> ---------------------------------------------------
> You can define more than one Package that triggers a hook, either
> separated by spaces in the "Package ="line, or in a separate "Package
> =" line
> or a mix of both. The "File = " argument can be anything that get
> matched by fnmatch(...). You can also use "Package" and "File" within
> the same hook.
> In this case either one of them will trigger the hook (in other words:
> Package || File).
> "When" can be one of the following: PreRemove, PostRemove, PreUpgrade,
> PostUpgrade, PreInstall or PostInstall.
So are these on a per-package or per-total-operation basis? A huge
part of hooks is something like installing a load of font packages;
any command that these would normally run is postponed until the end
of the transaction and then only needs to run once. Same for
icon-cache, info reindexing, etc. or whatever other things you see in
>5 install scripts of packages.
> For each hook, there needs to be a corresponding file in /etc/pacman.d/hooks.d.
> pacman.d
> ├── hooks.conf
> ├── hooks.d
> │ ├── fonts*
> │ └── testhook*
>
>
> Things i don't like, but i don't really now how to fix those:
> - The global variable HOOK_LIST
It belongs on the handle object, more than likely- this is where
everything global is captured.
> - The paths to hooks.d and hooks.conf are hardcoded
> - The parsing of the config file is really ugly
And also, seeing that the patch contains zero changes in src/...we
never ever parse config stuff in the backend, it needs to get passed
through by the frontend.
> - The "File" argument can't begin with a / because it is matched
> against alpm_pkg_get_data and that
> file-strings don't have the leading /
This is a must-have, your logic is backwards. We never assume the
install root is /; file paths in all install scripts should be written
this way too, not to mention everywhere in the library. So nothing
wrong here, it would be wrong if you did any prefix whatsoever.
>
>
> Greetings,
>
> Sascha Kruse
>
> P.s I don't mind, if you say, that this is too broken to get included.
>
>
> From 9ac289d0c495a05239441a8ffe33975f32c3ef97 Mon Sep 17 00:00:00 2001
> From: Sascha Kruse <knopwob at googlemail.com>
> Date: Sat, 29 Jan 2011 15:00:55 +0100
> Subject: [PATCH] hooks
>
> ---
> lib/libalpm/Makefile.am | 1 +
> lib/libalpm/add.c | 5 +
> lib/libalpm/alpm.c | 1 +
> lib/libalpm/hooks.c | 217 +++++++++++++++++++++++++++++++++++++++++++++++
> lib/libalpm/hooks.h | 43 +++++++++
> lib/libalpm/remove.c | 3 +
> lib/libalpm/trans.c | 2 +
> 7 files changed, 272 insertions(+), 0 deletions(-)
> create mode 100644 lib/libalpm/hooks.c
> create mode 100644 lib/libalpm/hooks.h
>
> diff --git a/lib/libalpm/Makefile.am b/lib/libalpm/Makefile.am
> index da663cb..f23da73 100644
> --- a/lib/libalpm/Makefile.am
> +++ b/lib/libalpm/Makefile.am
> @@ -38,6 +38,7 @@ libalpm_la_SOURCES = \
> graph.h \
> group.h group.c \
> handle.h handle.c \
> + hooks.h hooks.c \
> log.h log.c \
> package.h package.c \
> remove.h remove.c \
> diff --git a/lib/libalpm/add.c b/lib/libalpm/add.c
> index d4c56de..5bb0b0f 100644
> --- a/lib/libalpm/add.c
> +++ b/lib/libalpm/add.c
> @@ -48,6 +48,7 @@
> #include "deps.h"
> #include "remove.h"
> #include "handle.h"
> +#include "hooks.h"
>
> /** Add a file target to the transaction.
> * @param target the name of the file target to add
> @@ -516,6 +517,7 @@ static int commit_single_pkg(pmpkg_t *newpkg,
> size_t pkg_current,
> _alpm_runscriptlet(handle->root, newpkg->origin_data.file,
> "pre_upgrade", newpkg->version, oldpkg->version, trans);
> }
> + _trigger_hooks(newpkg, "PreUpgrade");
If the function is in another file, it should be named _alpm, which is
the standard prefix for "private" alpm functions.
> } else {
> is_upgrade = 0;
>
> @@ -528,6 +530,7 @@ static int commit_single_pkg(pmpkg_t *newpkg,
> size_t pkg_current,
> _alpm_runscriptlet(handle->root, newpkg->origin_data.file,
> "pre_install", newpkg->version, NULL, trans);
> }
> + _trigger_hooks(newpkg, "PreInstall");
> }
>
> /* we override any pre-set reason if we have alldeps or allexplicit set */
> @@ -696,9 +699,11 @@ static int commit_single_pkg(pmpkg_t *newpkg,
> size_t pkg_current,
> _alpm_runscriptlet(handle->root, scriptlet, "post_upgrade",
> alpm_pkg_get_version(newpkg),
> oldpkg ? alpm_pkg_get_version(oldpkg) : NULL, trans);
> + _trigger_hooks(newpkg, "PostUpgrade");
> } else {
> _alpm_runscriptlet(handle->root, scriptlet, "post_install",
> alpm_pkg_get_version(newpkg), NULL, trans);
> + _trigger_hooks(newpkg, "PostInstall");
> }
> }
>
> diff --git a/lib/libalpm/alpm.c b/lib/libalpm/alpm.c
> index 2a9f460..e72de6d 100644
> --- a/lib/libalpm/alpm.c
> +++ b/lib/libalpm/alpm.c
> @@ -63,6 +63,7 @@ int SYMEXPORT alpm_initialize(void)
> fetchConnectionCacheInit(5, 1);
> #endif
>
> + _parse_hooks_config();
DBPath, all other things, etc. haven't been set here so this is a
non-starter. But as I already mentioned anyway, I think the config
needs to come from the frontend so this will likely go away anyway.
> return(0);
> }
>
> diff --git a/lib/libalpm/hooks.c b/lib/libalpm/hooks.c
> new file mode 100644
> index 0000000..e1ecfab
> --- /dev/null
> +++ b/lib/libalpm/hooks.c
> @@ -0,0 +1,217 @@
> +/*
> + * package.h
> + *
> + * Copyright (c) 2006-2011 Pacman Development Team <pacman-dev at archlinux.org>
> + * Copyright (c) 2002-2006 by Judd Vinet <jvinet at zeroflux.org>
No need for the earlier copyright if this is a new file.
> + *
> + * 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 <alpm.h>
> +#include <alpm_list.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <ctype.h>
> +#include <stdlib.h>
> +#include <fnmatch.h>
> +/* pacman */
Um, we're in the backend, so this comment is definitely a no-go.
> +#include "package.h"
> +#include "util.h"
> +#include "hooks.h"
> +
> +
> +int _run_hook(hook_t *hook)
static
> +{
> + char *cmd;
> + int retval;
> +
> + cmd = malloc(strlen("/etc/pacman.d/hooks.d/") + strlen(hook->name) + 1);
Use MALLOC macros please.
> + sprintf(cmd, "/etc/pacman.d/hooks.d/%s", hook->name);
> +
> + retval = system(cmd);
Err...take a look at util.c:_alpm_run_chroot() and the places we use
that. You have tremendously oversimplified the setup necessary to run
external commands and have them operate on the correct root and paths.
> + if(retval == -1) {
> + } else if(retval != 0) {
> + }
I'll consider this work in progress?
> + return (retval);
> +}
> +
> +void _run_postponed_hooks(void)
static
> +{
> + hook_t *hook;
> + alpm_list_t *i;
> +
> + for(i = HOOK_LIST; i; i = alpm_list_next(i)) {
> + hook = alpm_list_getdata(i);
hook can be local inside this loop.
> + if(hook->triggered) {
> + _run_hook(hook);
> + }
> + }
> +}
> +
> +void _trigger_hooks(pmpkg_t *pkg, char *when)
const char *when
> +{
> + hook_t *hook;
> + alpm_list_t *i, *j, *k;
> + alpm_list_t *pkgfiles;
> + const char *pkgname;
> +
> + pkgname = alpm_pkg_get_name(pkg);
> + pkgfiles = alpm_pkg_get_files(pkg);
> +
> + for(i = HOOK_LIST; i; i = alpm_list_next(i)) {
> + hook = alpm_list_getdata(i);
> +
> + /* trigger package based hooks */
> + if(strcmp(hook->when, when) == 0 ||
> + strcmp(hook->when, "Transaction") == 0) {
Not following this logic...you are comparing to the passed in value
and to the static string "Transaction"? Where did that come from?
> + for(j = hook->pkg_triggers; j; j = alpm_list_next(j)) {
> + if(strcmp(pkgname, alpm_list_getdata(j)) == 0) {
> + if(strcmp(when, "Install") == 0
> + || strcmp(when, "PostInstall") == 0
> + || strcmp(when, "PreRemove") == 0) {
> + _run_hook(hook);
> + return;
> + } else {
> + hook->triggered++;
> + return;
> + }
> + }
> + }
> +
> + /* trigger file based hooks */
> + for(j = hook->file_triggers; j; j = alpm_list_next(j)) {
> + for(k = pkgfiles; k; k = alpm_list_next(k)) {
> + if(fnmatch(alpm_list_getdata(j), alpm_list_getdata(k), 0) == 0) {
j, k- please use more descriptive variables, and use a local var to
prevent calling getdata() multiple times on the same list variable.
> + if(strcmp(when, "Install") == 0
> + || strcmp(when, "PostInstall") == 0
> + || strcmp(when, "PreRemove") == 0) {
> + _run_hook(hook);
> + return;
> + } else {
> + hook->triggered++;
> + return;
> + }
> + }
> + }
> + }
> + }
> + }
> +}
> +
Yes, we do not want to reinvent parsing. This needs to find a way to
be incorporated into our parsing framework in the frontend.
> +int _parse_hooks_config(void)
> +{
> + FILE *config;
> + char linebuf[128];
> + char *cur, *look_ahead, *tmp, *key, *value;
> +
> + hook_t *tmp_hook = NULL;
> +
> +
> + config = fopen("/etc/pacman.d/hooks.conf", "r");
> +
> + HOOK_LIST = NULL;
> +
> + if(config == NULL) {
> + return (1);
> + }
> +
> + while(fgets(linebuf, 127, config)) {
> + /* skip over whitespaces */
> + for(cur = linebuf; isspace(*cur) ; cur++);
> +
> + /* ignore lines beginning with '#' */
> + if(*cur == '#') {
> + continue;
> + }
> + if(*cur == '\0') {
> + continue;
> + }
> +
> + if(*cur == '[') {
> + /* we enter a new section */
> + if(tmp_hook != NULL) {
> + /* ignore packages without name */
> + if(tmp_hook->name != NULL) {
> + HOOK_LIST = alpm_list_add(HOOK_LIST, tmp_hook);
> + }
> + }
> + tmp_hook = malloc(sizeof(hook_t));
> + tmp_hook->name = NULL;
> + tmp_hook->pkg_triggers = NULL;
> + tmp_hook->file_triggers = NULL;
> + tmp_hook->triggered = 0;
> + tmp_hook->when = 0;
> +
> + cur++;
> + for(look_ahead = cur; *look_ahead != ']' && *look_ahead != '\0';
> look_ahead++);
> + if(*look_ahead == '\0') {
> + return (2);
> + }
> +
> + tmp_hook->name = malloc(look_ahead - cur + 1);
> + strncpy(tmp_hook->name, cur, look_ahead - cur);
> + tmp_hook->name[look_ahead - cur] = '\0';
> + continue;
> + }
> +
> + key = cur;
> + value = strstr(linebuf, "=");
> + if(value == NULL) {
> + return (2);
> + }
> +
> + value++;
> + for(; isspace(*value) && *value != '\0'; value++);
> + if(*value == '\0') {
> + return 2;
> + }
> +
> + if(strncmp("Package", key, strlen("Package")) == 0) {
> + while(*value != '\0') {
> + for(look_ahead = value; isalnum(*look_ahead); look_ahead++);
> + tmp = malloc(look_ahead - value + 1);
> + strncpy(tmp, value, look_ahead - value);
> + tmp[look_ahead - value] = '\0';
> + tmp_hook->pkg_triggers = alpm_list_add(tmp_hook->pkg_triggers, tmp);
> + tmp = NULL;
> + value = look_ahead+1;
> + /* skip whitespaces */
> + for(; isspace(*value) ; value++);
> + }
> + }
> +
> + if(strncmp("File", key, strlen("File")) == 0) {
> + for(look_ahead = value; *look_ahead != '\n'; look_ahead++);
> + tmp = malloc(look_ahead - value + 1);
> + strncpy(tmp, value, look_ahead - value);
> + tmp[look_ahead - value + 1] = '\0';
> + tmp_hook->file_triggers = alpm_list_add(tmp_hook->file_triggers, tmp);
> + }
> + if(strncmp("When", key, strlen("When")) == 0) {
> + for(look_ahead = value; isalnum(*look_ahead); look_ahead++);
> + tmp_hook->when = malloc(look_ahead - value + 1);
> + strncpy(tmp_hook->when, value, look_ahead - value);
> + tmp_hook->when[look_ahead - value] = '\0';
> + }
> + }
> + if(tmp_hook != NULL) {
> + /* ignore hooks without name */
> + if(tmp_hook->name != NULL) {
> + HOOK_LIST = alpm_list_add(HOOK_LIST, tmp_hook);
> + }
> + }
> + return 0;
> +}
> +/* vim: set ts=2 sw=2 noet: */
> diff --git a/lib/libalpm/hooks.h b/lib/libalpm/hooks.h
> new file mode 100644
> index 0000000..15bd47e
> --- /dev/null
> +++ b/lib/libalpm/hooks.h
> @@ -0,0 +1,43 @@
> +/*
> + * package.h
> + *
> + * Copyright (c) 2006-2011 Pacman Development Team <pacman-dev at archlinux.org>
> + * Copyright (c) 2002-2006 by Judd Vinet <jvinet at zeroflux.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/>.
> + */
> +
> +#ifndef _PM_HOOKS_H
> +#define _PM_HOOKS_H
> +
> +#include <alpm.h>
> +
> +typedef struct hook {
> + char *name;
> + alpm_list_t *pkg_triggers;
> + alpm_list_t *file_triggers;
> + int triggered;
> + char *when;
> +} hook_t;
> +
> +/* global Variables */
> +alpm_list_t *HOOK_LIST;
> +
> +
> +void _run_postponed_hooks(void);
> +void _trigger_hooks(pmpkg_t *pkg, char *when);
> +int _parse_hooks_config(void);
> +#endif /* _PM_HOOKS_H */
> +
> +/* vim: set ts=2 sw=2 noet: */
> diff --git a/lib/libalpm/remove.c b/lib/libalpm/remove.c
> index 5fba0b0..3bd32e2 100644
> --- a/lib/libalpm/remove.c
> +++ b/lib/libalpm/remove.c
> @@ -45,6 +45,7 @@
> #include "deps.h"
> #include "handle.h"
> #include "alpm.h"
> +#include "hooks.h"
>
> int SYMEXPORT alpm_remove_target(const char *target)
> {
> @@ -409,6 +410,7 @@ int _alpm_remove_packages(pmtrans_t *trans, pmdb_t *db)
> _alpm_runscriptlet(handle->root, scriptlet, "pre_remove",
> alpm_pkg_get_version(info), NULL, trans);
> }
> + _trigger_hooks(info, "PreRemove");
>
> if(!(trans->flags & PM_TRANS_FLAG_DBONLY)) {
> alpm_list_t *files = alpm_pkg_get_files(info);
> @@ -454,6 +456,7 @@ int _alpm_remove_packages(pmtrans_t *trans, pmdb_t *db)
> _alpm_runscriptlet(handle->root, scriptlet, "post_remove",
> alpm_pkg_get_version(info), NULL, trans);
> }
> + _trigger_hooks(info, "PostRemve");
Typo is probably going to not work out well. We should probably be
using some sort of enum so we can be type-safe anyway.
>
> /* remove the package from the database */
> _alpm_log(PM_LOG_DEBUG, "updating database\n");
> diff --git a/lib/libalpm/trans.c b/lib/libalpm/trans.c
> index 804ab7a..64b6e7d 100644
> --- a/lib/libalpm/trans.c
> +++ b/lib/libalpm/trans.c
> @@ -45,6 +45,7 @@
> #include "sync.h"
> #include "alpm.h"
> #include "deps.h"
> +#include "hooks.h"
>
> /** \addtogroup alpm_trans Transaction Functions
> * @brief Functions to manipulate libalpm transactions
> @@ -209,6 +210,7 @@ int SYMEXPORT alpm_trans_commit(alpm_list_t **data)
> return(-1);
> }
> }
> + _run_postponed_hooks();
Is the ldconfig call around here? I would expect it to be as that is
the closest thing we have to a delayed hook right now.
> trans->state = STATE_COMMITED;
>
> --
> 1.7.3.5
>
>
>
>
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