sg_path.cxx

// sg_path.cxx -- routines to abstract out path separator differences
//               between MacOS and the rest of the world
//
// Written by Curtis L. Olson, started April 1999.
//
// Copyright (C) 1999  Curtis L. Olson - http://www.flightgear.org/~curt
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Library 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 Street, Fifth Floor, Boston, MA  02110-1301, USA.
//
// $Id: sg__path_8cxx_source.html,v 1.3 2010/02/23 22:10:16 curt Exp $


#include <simgear/compiler.h>

#include <simgear_config.h>
#include <simgear/debug/logstream.hxx>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/stat.h>
#ifdef _WIN32
#  include <direct.h>
#endif
#include "sg_path.hxx"


static const char sgDirPathSep = '/';
static const char sgDirPathSepBad = '\\';

#ifdef _WIN32
static const char sgSearchPathSep = ';';
#else
static const char sgSearchPathSep = ':';
#endif


// If Unix, replace all ":" with "/".  If MacOS, replace all "/" with
// ":" it should go without saying that neither of these characters
// should be used in file or directory names.  In windoze, allow the
// second character to be a ":" for things like c:\foo\bar

void
SGPath::fix()
{
    for ( string::size_type i = 0; i < path.size(); ++i ) {
#if defined( WIN32 )
        // for windoze, don't replace the ":" for the second character
        if ( i == 1 ) {
            continue;
        }
#endif
        if ( path[i] == sgDirPathSepBad ) {
            path[i] = sgDirPathSep;
        }
    }
}


// default constructor
SGPath::SGPath()
    : path("")
{
}


// create a path based on "path"
SGPath::SGPath( const std::string& p )
    : path(p)
{
    fix();
}


// destructor
SGPath::~SGPath() {
}


// set path
void SGPath::set( const string& p ) {
    path = p;
    fix();
}


// append another piece to the existing path
void SGPath::append( const string& p ) {
    if ( path.size() == 0 ) {
        path = p;
    } else {
        if ( p[0] != sgDirPathSep ) {
            path += sgDirPathSep;
        }
        path += p;
    }
    fix();
}

//add a new path component to the existing path string
void SGPath::add( const string& p ) {
    append( sgSearchPathSep+p );
}


// concatenate a string to the end of the path without inserting a
// path separator
void SGPath::concat( const string& p ) {
    if ( path.size() == 0 ) {
        path = p;
    } else {
        path += p;
    }
    fix();
}


// Get the file part of the path (everything after the last path sep)
string SGPath::file() const {
    int index = path.rfind(sgDirPathSep);
    if (index >= 0) {
        return path.substr(index + 1);
    } else {
        return "";
    }
}
  

// get the directory part of the path.
string SGPath::dir() const {
    int index = path.rfind(sgDirPathSep);
    if (index >= 0) {
        return path.substr(0, index);
    } else {
        return "";
    }
}

// get the base part of the path (everything but the extension.)
string SGPath::base() const {
    int index = path.rfind(".");
    if ((index >= 0) && (path.find("/", index) == string::npos)) {
        return path.substr(0, index);
    } else {
        return "";
    }
}

// get the extension (everything after the final ".")
// but make sure no "/" follows the "." character (otherwise it
// is has to be a directory name containing a ".").
string SGPath::extension() const {
    int index = path.rfind(".");
    if ((index >= 0)  && (path.find("/", index) == string::npos)) {
        return path.substr(index + 1);
    } else {
        return "";
    }
}

bool SGPath::exists() const {
    FILE* fp = fopen( path.c_str(), "r");
    if (fp == 0) {
        return false;
    }
    fclose(fp);
    return true;
}

#ifdef _WIN32
#  define sgMkDir(d,m)       _mkdir(d)
#else
#  define sgMkDir(d,m)       mkdir(d,m)
#endif


int SGPath::create_dir( mode_t mode ) {
    string_list dirlist = sgPathSplit(dir());
    if ( dirlist.empty() )
        return -1;
    string path = dirlist[0];
    string_list path_elements = sgPathBranchSplit(path);
    bool absolute = !path.empty() && path[0] == sgDirPathSep;

    unsigned int i = 1;
    SGPath dir = absolute ? string( 1, sgDirPathSep ) : "";
    dir.concat( path_elements[0] );
#ifdef _WIN32
    if ( dir.str().find(':') != string::npos && path_elements.size() >= 2 ) {
        dir.append( path_elements[1] );
        i = 2;
    }
#endif
    struct stat info;
    int r;
    for(; ( r = stat( dir.c_str(), &info ) ) == 0 && i < path_elements.size(); i++) {
        dir.append(path_elements[i]);
    }
    if ( r == 0 ) {
        return 0; // Directory already exists
    }
    if ( sgMkDir( dir.c_str(), mode) ) {
        SG_LOG( SG_IO, SG_ALERT, "Error creating directory: " + dir.str() );
        return -2;
    }
    for(; i < path_elements.size(); i++) {
        dir.append(path_elements[i]);
        if ( sgMkDir( dir.c_str(), mode) ) {
            SG_LOG( SG_IO, SG_ALERT, "Error creating directory: " + dir.str() );
            return -2;
        }
    }

    return 0;
}

string_list sgPathBranchSplit( const string &dirpath ) {
    string_list path_elements;
    string element, path = dirpath;
    while ( path.size() ) {
        size_t p = path.find( sgDirPathSep );
        if ( p != string::npos ) {
            element = path.substr( 0, p );
            path.erase( 0, p + 1 );
        } else {
            element = path;
            path = "";
        }
        if ( element.size() )
            path_elements.push_back( element );
    }
    return path_elements;
}


string_list sgPathSplit( const string &search_path ) {
    string tmp = search_path;
    string_list result;
    result.clear();

    bool done = false;

    while ( !done ) {
        int index = tmp.find(sgSearchPathSep);
        if (index >= 0) {
            result.push_back( tmp.substr(0, index) );
            tmp = tmp.substr( index + 1 );
        } else {
            if ( !tmp.empty() )
                result.push_back( tmp );
            done = true;
        }
    }

    return result;
}

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