/* Copyright (C) 2004 J.F.Dockes
* 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.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef TEST_MIMETYPE
#include "autoconfig.h"
#include "safesysstat.h"
#include <ctype.h>
#include <string>
#include <list>
using namespace std;
#include "mimetype.h"
#include "log.h"
#include "execmd.h"
#include "rclconfig.h"
#include "smallut.h"
#include "idfile.h"
#include "pxattr.h"
/// Identification of file from contents. This is called for files with
/// unrecognized extensions.
///
/// The system 'file' utility does not always work for us. For exemple
/// it will mistake mail folders for simple text files if there is no
/// 'Received' header, which would be the case, for exemple in a
/// 'Sent' folder. Also "file -i" does not exist on all systems, and
/// is quite costly to execute.
/// So we first call the internal file identifier, which currently
/// only knows about mail, but in which we can add the more
/// current/interesting file types.
/// As a last resort we execute 'file' or its configured replacement
/// (except if forbidden by config)
static string mimetypefromdata(RclConfig *cfg, const string &fn, bool usfc)
{
// First try the internal identifying routine
string mime = idFile(fn.c_str());
#ifdef USE_SYSTEM_FILE_COMMAND
if (usfc && mime.empty()) {
// Last resort: use "file -i", or its configured replacement.
// 'file' fallback if the configured command (default:
// xdg-mime) is not found
static const vector<string> tradfilecmd =
create_vector<string>(FILE_PROG) ("-i") (fn);
vector<string> cmd;
string scommand;
if (cfg->getConfParam("systemfilecommand", scommand)) {
LOGDEB2("mimetype: syscmd from config: " << (scommand) << "\n" );
stringToStrings(scommand, cmd);
string exe;
if (cmd.empty()) {
cmd = tradfilecmd;
} else if (!ExecCmd::which(cmd[0], exe)) {
cmd = tradfilecmd;
} else {
cmd[0] = exe;
}
cmd.push_back(fn);
} else {
LOGDEB("mimetype:systemfilecommand not found, using " << (stringsToString(tradfilecmd)) << "\n" );
cmd = tradfilecmd;
}
string result;
if (!ExecCmd::backtick(cmd, result)) {
LOGERR("mimetypefromdata: exec " << (stringsToString(cmd)) << " failed\n" );
return string();
}
trimstring(result, " \t\n\r");
LOGDEB2("mimetype: systemfilecommand output [" << (result) << "]\n" );
// The normal output from "file -i" looks like the following:
// thefilename.xxx: text/plain; charset=us-ascii
// Sometimes the semi-colon is missing like in:
// mimetype.cpp: text/x-c charset=us-ascii
// And sometimes we only get the mime type. This apparently happens
// when 'file' believes that the file name is binary
// xdg-mime only outputs the MIME type.
// If there is no colon and there is a slash, this is hopefuly
// the mime type
if (result.find_first_of(":") == string::npos &&
result.find_first_of("/") != string::npos) {
return result;
}
// Else the result should begin with the file name. Get rid of it:
if (result.find(fn) != 0) {
// Garbage "file" output. Maybe the result of a charset
// conversion attempt?
LOGERR("mimetype: can't interpret 'file' output: [" << (result) << "]\n" );
return string();
}
result = result.substr(fn.size());
// Now should look like ": text/plain; charset=us-ascii"
// Split it, and take second field
list<string> res;
stringToStrings(result, res);
if (res.size() <= 1)
return string();
list<string>::iterator it = res.begin();
mime = *++it;
// Remove possible semi-colon at the end
trimstring(mime, " \t;");
// File -i will sometimes return strange stuff (ie: "very small file")
if(mime.find("/") == string::npos)
mime.clear();
}
#endif //USE_SYSTEM_FILE_COMMAND
return mime;
}
/// Guess mime type, first from suffix, then from file data. We also
/// have a list of suffixes that we don't touch at all.
string mimetype(const string &fn, const struct stat *stp,
RclConfig *cfg, bool usfc)
{
// Use stat data if available to check for non regular files
if (stp) {
// Note: the value used for directories is different from what
// file -i would print on Linux (inode/directory). Probably
// comes from bsd. Thos may surprise a user trying to use a
// 'mime:' filter with the query language, but it's not work
// changing (would force a reindex).
if (S_ISDIR(stp->st_mode))
return "inode/directory";
if (S_ISLNK(stp->st_mode))
return "inode/symlink";
if (!S_ISREG(stp->st_mode))
return "inode/x-fsspecial";
// Empty files are just this: avoid further errors with actual filters.
if (stp->st_size == 0)
return "inode/x-empty";
}
string mtype;
#ifndef _WIN32
// Extended attribute has priority on everything, as per:
// http://freedesktop.org/wiki/CommonExtendedAttributes
if (pxattr::get(fn, "mime_type", &mtype)) {
LOGDEB0("Mimetype: 'mime_type' xattr : [" << (mtype) << "]\n" );
if (mtype.empty()) {
LOGDEB0("Mimetype: getxattr() returned empty mime type !\n" );
} else {
return mtype;
}
}
#endif
if (cfg == 0) {
LOGERR("Mimetype: null config ??\n" );
return mtype;
}
if (cfg->inStopSuffixes(fn)) {
LOGDEB("mimetype: fn [" << (fn) << "] in stopsuffixes\n" );
return mtype;
}
// Compute file name suffix and search the mimetype map
string::size_type dot = fn.find_first_of(".");
while (dot != string::npos) {
string suff = stringtolower(fn.substr(dot));
mtype = cfg->getMimeTypeFromSuffix(suff);
if (!mtype.empty() || dot >= fn.size() - 1)
break;
dot = fn.find_first_of(".", dot + 1);
}
// If type was not determined from suffix, examine file data. Can
// only do this if we have an actual file (as opposed to a pure
// name).
if (mtype.empty() && stp)
mtype = mimetypefromdata(cfg, fn, usfc);
return mtype;
}
#else // TEST->
#include <stdio.h>
#include "safesysstat.h"
#include <cstdlib>
#include <iostream>
#include "log.h"
#include "rclconfig.h"
#include "rclinit.h"
#include "mimetype.h"
using namespace std;
int main(int argc, const char **argv)
{
string reason;
RclConfig *config = recollinit(0, 0, reason);
if (config == 0 || !config->ok()) {
string str = "Configuration problem: ";
str += reason;
fprintf(stderr, "%s\n", str.c_str());
exit(1);
}
while (--argc > 0) {
string filename = *++argv;
struct stat st;
if (lstat(filename.c_str(), &st)) {
fprintf(stderr, "Can't stat %s\n", filename.c_str());
continue;
}
cout << filename << " -> " <<
mimetype(filename, &st, config, true) << endl;
}
return 0;
}
#endif // TEST