Aegisub/csri/lib/posix/enumerate.c

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/*****************************************************************************
* asa: portable digital subtitle renderer
*****************************************************************************
* Copyright (C) 2007 David Lamparter
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
****************************************************************************/
#define _POSIX_C_SOURCE 200112L /* for PATH_MAX */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <limits.h>
#include <dlfcn.h>
#include "../csrilib.h"
#include "subhelp.h"
static const char csri_path[] = CSRI_PATH;
static void csrilib_enum_dir(const char *dir);
static void csrilib_add(csri_rend *rend,
const struct csri_wrap_rend *tmp, struct csri_info *info)
{
struct csri_wrap_rend *wrend = (struct csri_wrap_rend *)
malloc(sizeof(struct csri_wrap_rend));
if (!wrend)
return;
memcpy(wrend, tmp, sizeof(struct csri_wrap_rend));
wrend->rend = rend;
wrend->info = info;
csrilib_rend_initadd(wrend);
}
static void csrilib_do_load(const char *filename, dev_t device, ino_t inode)
{
void *dlhandle = dlopen(filename, RTLD_NOW);
struct csri_wrap_rend tmp;
csri_rend *rend;
struct csri_info *(*renderer_info)(csri_rend *rend);
csri_rend *(*renderer_default)();
csri_rend *(*renderer_next)(csri_rend *prev);
const char *sym;
if (!dlhandle) {
subhelp_log(CSRI_LOG_WARNING, "dlopen(\"%s\") says: %s",
filename, dlerror());
return;
}
if (dlsym(dlhandle, "csri_library")) {
subhelp_log(CSRI_LOG_WARNING, "ignoring library %s",
filename);
return;
}
subhelp_log(CSRI_LOG_INFO, "loading %s", filename);
tmp.os.dlhandle = dlhandle;
tmp.os.device = device;
tmp.os.inode = inode;
/* okay, this is uber-ugly. either I end up casting from void *
* to a fptr (which yields a cast warning), or I do a *(void **)&tmp.x
* (which yields a strict-aliasing warning).
* casting via char* works because char* can alias anything.
*/
#define _dl_map_function(x, dst) do { \
char *t1 = (char *)&dst; \
union x { void *ptr; } *ptr = (union x *)t1; \
sym = "csri_" # x; \
ptr->ptr = dlsym(dlhandle, sym);\
if (!ptr->ptr) goto out_dlfail; } while (0)
#define dl_map_function(x) _dl_map_function(x, tmp.x)
dl_map_function(query_ext);
subhelp_logging_pass((struct csri_logging_ext *)
tmp.query_ext(NULL, CSRI_EXT_LOGGING));
dl_map_function(open_file);
dl_map_function(open_mem);
dl_map_function(close);
dl_map_function(request_fmt);
dl_map_function(render);
#define dl_map_local(x) _dl_map_function(x, x)
dl_map_local(renderer_info);
dl_map_local(renderer_default);
dl_map_local(renderer_next);
rend = renderer_default();
while (rend) {
csrilib_add(rend, &tmp, renderer_info(rend));
rend = renderer_next(rend);
}
return;
out_dlfail:
subhelp_log(CSRI_LOG_WARNING, "%s: symbol %s not found (%s)",
filename, sym, dlerror());
dlclose(dlhandle);
}
static void csrilib_load(const char *filename)
{
struct csri_wrap_rend *rend;
struct stat st;
if (stat(filename, &st))
return;
if (S_ISDIR(st.st_mode)) {
csrilib_enum_dir(filename);
return;
}
if (!S_ISREG(st.st_mode))
return;
if (access(filename, X_OK))
return;
for (rend = wraprends; rend; rend = rend->next)
if (rend->os.device == st.st_dev
&& rend->os.inode == st.st_ino)
return;
csrilib_do_load(filename, st.st_dev, st.st_ino);
}
static void csrilib_enum_dir(const char *dir)
{
DIR *dirh;
struct dirent *e;
char buf[PATH_MAX];
dirh = opendir(dir);
if (!dirh) {
subhelp_log(CSRI_LOG_WARNING, "ignoring directory \"%s\":"
" %s (%d)", dir, strerror(errno), errno);
return;
}
subhelp_log(CSRI_LOG_INFO, "scanning directory \"%s\"", dir);
while ((e = readdir(dirh))) {
if (e->d_name[0] == '.')
continue;
snprintf(buf, sizeof(buf), "%s/%s", dir, e->d_name);
csrilib_load(buf);
}
closedir(dirh);
}
static void csrilib_expand_enum_dir(const char *dir)
{
if (dir[0] == '~' && (dir[1] == '\0' || dir[1] == '/')) {
char buf[PATH_MAX], *home = getenv("HOME");
if (!home)
home = "";
snprintf(buf, sizeof(buf), "%s%s", home, dir + 1);
csrilib_enum_dir(buf);
} else
csrilib_enum_dir(dir);
}
void csrilib_os_init()
{
char buf[4096];
char *envpath = getenv("CSRI_PATH");
char *pos, *next = buf;
if (envpath)
snprintf(buf, sizeof(buf), "%s:%s", csri_path, envpath);
else {
strncpy(buf, csri_path, sizeof(buf));
buf[sizeof(buf) - 1] = '\0';
}
do {
pos = next;
next = strchr(pos, ':');
if (next)
*next++ = '\0';
csrilib_expand_enum_dir(pos);
} while (next);
}