[PATCH] config-parser: Honor the XDG_CONFIG_DIRS environment variable
Kristian Høgsberg
krh at bitplanet.net
Sun May 12 08:54:32 PDT 2013
Hi Ossama,
I think we can change the interface to int open_config_file(const char
*), which looks up and opens the config file and returns the fd. We
can keep that in weston_compositor instead of the config_file path.
The parse function can then fseek on the fd to reset to the beginning
of the file. Going forward, we'll do something like this:
http://lists.freedesktop.org/archives/wayland-devel/2013-April/008333.html
and store the weston_config object in weston_compositor object. The
config path patch here is somewhat orthogonal to that though.
On Sun, May 12, 2013 at 2:20 AM, Othman, Ossama <ossama.othman at intel.com> wrote:
> I've revised the patch to build a list of possible filenames as Bill
> suggested. This time around I've included a patch for the man page, as
> well.
>
> Thanks!
> -Ossama
>
> ---
>
> Search for a given config file in the directories listed in
> $XDG_CONFIG_DIRS if it wasn't found in $XDG_CONFIG_HOME or ~/.config.
> This allows packages to install custom config files in
> /etc/xdg/weston, for example, thus allowing them to avoid dealing with
> home directories.
>
> Signed-off-by: Ossama Othman <ossama.othman at intel.com>
> ---
> man/weston.ini.man | 12 +++-
> shared/config-parser.c | 155
> +++++++++++++++++++++++++++++++++++++++++-------
> 2 files changed, 142 insertions(+), 25 deletions(-)
>
> diff --git a/man/weston.ini.man b/man/weston.ini.man
> index 2287730..d37654a 100644
> --- a/man/weston.ini.man
> +++ b/man/weston.ini.man
> @@ -24,7 +24,10 @@ server is started:
> .nf
> .BR "$XDG_CONFIG_HOME/weston.ini " "(if $XDG_CONFIG_HOME is set)"
> .BR "$HOME/.config/weston.ini " "(if $HOME is set)"
> -.BR "<current dir>/weston.ini " "(if both variables were not set)"
> +.B "weston/weston.ini in each"
> +.BR "\ \ \ \ $XDG_CONFIG_DIR " "(if $XDG_CONFIG_DIRS is set)"
> +.BR "/etc/xdg/weston/weston.ini " "(if $XDG_CONFIG_DIRS is not set)"
> +.BR "<current dir>/weston.ini " "(if no variables were set)"
> .fi
> .RE
> .PP
> @@ -32,7 +35,12 @@ where environment variable
> .B $HOME
> is the user's home directory, and
> .B $XDG_CONFIG_HOME
> -is the user specific configuration directory.
> +is the user specific configuration directory, and
> +.B $XDG_CONFIG_DIRS
> +is a colon
> +.B ':'
> +delimited listed of configuration base directories, such as
> +.BR /etc/xdg-foo:/etc/xdg .
> .PP
> The
> .I weston.ini
> diff --git a/shared/config-parser.c b/shared/config-parser.c
> index 10ff86a..4ebd453 100644
> --- a/shared/config-parser.c
> +++ b/shared/config-parser.c
> @@ -25,6 +25,7 @@
> #include <stdlib.h>
> #include <assert.h>
> #include <ctype.h>
> +#include <unistd.h>
>
> #include "config-parser.h"
>
> @@ -95,6 +96,9 @@ parse_config_file(const char *path,
> const struct config_section *current = NULL;
> int i;
>
> + if (path == NULL)
> + return -1;
> +
> fp = fopen(path, "r");
> if (fp == NULL) {
> fprintf(stderr, "couldn't open %s\n", path);
> @@ -151,37 +155,142 @@ parse_config_file(const char *path,
> return 0;
> }
>
> -char *
> -config_file_path(const char *name)
> +struct config_info
> {
> - const char dotconf[] = "/.config/";
> - const char *config_dir;
> - const char *home_dir;
> + /* Array of config file paths. */
> + char **paths;
> +
> + /* Number of elements in the "paths" array. */
> + size_t count;
> +};
> +
> +static char *
> +allocate_config_file_path(struct config_info *info, size_t path_size)
> +{
> + char **paths;
> char *path;
> - size_t size;
> -
> - config_dir = getenv("XDG_CONFIG_HOME");
> - if (!config_dir) {
> - home_dir = getenv("HOME");
> - if (!home_dir) {
> - fprintf(stderr, "HOME is not set, using cwd.\n");
> - return strdup(name);
> +
> + if (!info)
> + return 0;
> +
> + path = malloc(path_size);
> + if (path) {
> + paths = realloc(info->paths,
> + (info->count + 1) * sizeof(*(info->paths)));
> + if (paths) {
> + paths[info->count] = path;
> + info->paths = paths;
> + ++info->count;
> + } else {
> + free(path);
> + path = NULL;
> }
> + }
> +
> + return path;
> +}
> +
> +char *
> +config_file_path(const char *name)
> +{
> + const char *config_dir = getenv("XDG_CONFIG_HOME");
> + const char *home_dir = getenv("HOME");
> + const char *config_dirs = getenv("XDG_CONFIG_DIRS");
> + static const char weston_dir[] = "/weston/";
> + static const char cwd[] = "./";
> + static const int DEFAULT_DIR_COUNT = 5;
> + struct config_info info;
> + size_t name_len, size;
> + char *path, *dir, *saveptr, *tmp_dirs;
> + char **p;
> +
> + info.count = 0;
> + info.paths = malloc(DEFAULT_DIR_COUNT * sizeof(char *));
> + if (info.paths == NULL)
> + return NULL;
I don't think this function should need any mallocs at all. Basically
we should be able to say something like
char path[PATHMAX];
snprintf(path, size, "%s%s%s", home_dir, dotconf, name);
fd = open(path);
if (fd >= 0)
return fd;
/* same for XDG_CONFIG_DIR */
as for XDG_CONFIG_PATHS, I'd just scan through the string manually
with strchrnul instead of bothering with copying and strtok_r:
for (p = config_dirs, *p; p = next) {
next = strchrnul(p, ':');
snprintf(path, size, "%s/weston/%s", p next - p, name);
fd = open(path);
> +
> + name_len = strlen(name);
>
> - size = strlen(home_dir) + sizeof dotconf + strlen(name);
> - path = malloc(size);
> - if (!path)
> - return NULL;
> + /* Precedence is given to config files in the home directory,
> + * and then to directories listed in XDG_CONFIG_DIRS and
> + * finally to the current working directory. */
>
> - snprintf(path, size, "%s%s%s", home_dir, dotconf, name);
> - return path;
> + /* $XDG_CONFIG_HOME */
> + if (config_dir) {
> + size = strlen(config_dir) + 1 + name_len + 1;
> + path = allocate_config_file_path(&info, size);
> +
> + if (path)
> + snprintf(path, size, "%s/%s", config_dir, name);
> }
>
> - size = strlen(config_dir) + 1 + strlen(name) + 1;
> - path = malloc(size);
> - if (!path)
> + /* $HOME/.config */
> + if (home_dir) {
> + static const char dotconf[] = "/.config/";
> +
> + size = strlen(home_dir) + sizeof dotconf + name_len;
> + path = allocate_config_file_path(&info, size);
> +
> + if (path)
> + snprintf(path, size, "%s%s%s",
> + home_dir, dotconf, name);
> + }
> +
> + /* For each $XDG_CONFIG_DIRS: weston/<config_file> */
> + if (!config_dirs)
> + config_dirs = "/etc/xdg"; /* See XDG base dir spec. */
> +
> + size = strlen(config_dirs) + 1;
> + tmp_dirs = malloc(size);
> + if (!tmp_dirs)
> return NULL;
>
> - snprintf(path, size, "%s/%s", config_dir, name);
> + /* strtok_r() modifies the first argument. Avoid
> + * clobbering the process environment. */
> + strncpy(tmp_dirs, config_dirs, size);
> +
> + for (dir = strtok_r(tmp_dirs, ":", &saveptr);
> + dir != NULL;
> + dir = strtok_r(NULL, ":", &saveptr)) {
> + size = strlen(dir) + sizeof weston_dir + name_len;
> + path = allocate_config_file_path(&info, size);
> +
> + if (path)
> + snprintf(path, size, "%s%s%s", dir, weston_dir, name);
> + }
> +
> + free(tmp_dirs);
> +
> + /* Current working directory. */
> + size = sizeof cwd + name_len;
> + path = allocate_config_file_path(&info, size);
> +
> + if (path)
> + snprintf(path, size, "%s%s", cwd, name);
> +
> + path = NULL;
> +
> + /* Search for usable configuration file. */
> + for (p = info.paths; p != info.paths + info.count; ++p) {
> + /* Use the first found config file.
> + *
> + * FIXME: TOCTOU race here. Ideally we should open the
> + * file and return a handle to it. */
> + if (!path && access(*p, R_OK) == 0)
> + path = *p;
> + else
> + free(*p);
> + }
> +
> + if (path == info.paths[info.count - 1])
> + fprintf(stderr, "HOME is not set, using cwd.\n");
> +
> + free(info.paths);
> +
> + if (!path)
> + fprintf(stderr,
> + "config file \"%s\" not found.\n",
> + name);
> +
> return path;
> }
> --
> 1.7.10.4
>
>
> _______________________________________________
> wayland-devel mailing list
> wayland-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/wayland-devel
>
More information about the wayland-devel
mailing list