generic/general/ospath.c

/*  ASCEND modelling environment
    Copyright (C) 2006 Carnegie Mellon University

    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, 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.
*//**
    @file
    Platform-agnostic filesystem path manipulation functions.
    By John Pye.
*/

#include <string.h>
#include <malloc.h>
#include <stdio.h>
#include <ctype.h>

#include "ospath.h"

// to test this code, 'gcc -DTEST ospath.c && ./a'

#if defined(WIN32) || defined(__WIN32) || defined(_MSC_VER)
# ifndef __WIN32__
#  define __WIN32__
# endif
#endif

#define VERBOSE

#if !defined(TEST) && !defined(VERBOSE)
# define NDEBUG
#endif

//#define TRY_GETPWUID

#define DO_FIXSLASHES

#ifndef NDEBUG
# include <assert.h>
# define M(MSG) fprintf(stderr,"%s:%d: (%s) %s\n",__FILE__,__LINE__,__FUNCTION__,MSG);fflush(stderr);fflush(stderr)
# define MC(CLR,MSG) fprintf(stderr,"%c[%sm%s:%d: (%s) %s%c[0m\n",27,CLR,__FILE__,__LINE__,__FUNCTION__,MSG,27);fflush(stderr)
# define MM(MSG) MC("34",MSG)
# define X(VAR) fprintf(stderr,"%s:%d: (%s) %s=%s\n",__FILE__,__LINE__,__FUNCTION__,#VAR,VAR);fflush(stderr)
# define C(VAR) fprintf(stderr,"%s:%d: (%s) %s=%c\n",__FILE__,__LINE__,__FUNCTION__,#VAR,VAR);fflush(stderr)
# define V(VAR) fprintf(stderr,"%s:%d: (%s) %s=%d\n",__FILE__,__LINE__,__FUNCTION__,#VAR,(VAR));fflush(stderr)
# define D(VAR) fprintf(stderr,"%s:%d: (%s) %s=",__FILE__,__LINE__,__FUNCTION__,#VAR);ospath_debug(VAR);fflush(stderr)
# define DD(VAR) fprintf(stderr,"%c[34;1m%s:%d: (%s)%c[0m %s=",27,__FILE__,__LINE__,__FUNCTION__,27,#VAR);ospath_debug(VAR);fflush(stderr)
#else
# include <assert.h>
# define M(MSG) ((void)0)
# define MC(CLR,MSG) ((void)0)
# define X(VAR) ((void)0)
# define C(VAR) ((void)0)
# define V(VAR) ((void)0)
# define D(VAR) ((void)0)
# define DD(VAR) ((void)0)
# define MM(VAR) ((void)0)
#endif

#if defined(__WIN32__) && !defined(__MINGW32__)
# define STRCPY strcpy
# define STRNCPY(dest,src,n) strncpy_s(dest,n,src,n)
# define STRCAT strcat
# define STRNCAT strncat
# define STRTOK(STR,PAT,VAR) strtok_s(STR,PAT,&VAR)
# define STRTOKVAR(VAR) char *VAR
# define GETCWD getcwd
# define GETENV(VAR) getenv(VAR)
#else
# define STRCPY strcpy
# define STRNCPY(dest,src,n) strncpy(dest,src,n)
# define STRCAT strcat
# define STRNCAT strncat
# define STRTOK(STR,PAT,VAR) strtok(STR,PAT)
# define STRTOKVAR(VAR) ((void)0)
# define GETCWD getcwd
# define GETENV(VAR) getenv(VAR)
#endif

// PATH_MAX is in ospath.h
#define DRIVEMAX 3
#define LISTMAX 256

#ifdef __WIN32__ /* && !defined(__MINGW32__) */
# define WINPATHS
#endif

struct FilePath{
    char path[PATH_MAX]; /// the string version of the represented POSIX path

#ifdef WINPATHS
    char drive[DRIVEMAX]; /// the drive the path resides on (field is absent in POSIX systems)
#endif
};

#include <string.h>

#if !defined(MALLOC) && !defined(FREE)
# define MALLOC malloc
# define FREE free
#endif

#define E(MSG) fprintf(stderr,"%s:%d: (%s) ERROR: %s\n",__FILE__,__LINE__,__FUNCTION__,MSG)

#ifdef DO_FIXSLASHES
void ospath_fixslash(char *path);
#endif

struct FilePath *ospath_getcwd();

void ospath_copy(struct FilePath *dest, struct FilePath *src);


#ifdef WINPATHS
/**
    This function splits out the drive letter in the path string, thus completing
    the correct construction of a FilePath object under Win32.
*/
void ospath_extractdriveletter(struct FilePath *);
#endif

#ifdef WINPATHS
# define PATH_SEPARATOR_STR  "\\"
# define PATH_SEPARATOR_CHAR  '\\'
# define PATH_LISTSEP_CHAR ';'
# define PATH_LISTSEP_STR ";"
# define PATH_WRONGSLASH_CHAR '/'
# define PATH_WRONGSLASH_STR "/"
#else
# define PATH_SEPARATOR_STR "/"
# define PATH_SEPARATOR_CHAR '/'
# define PATH_LISTSEP_CHAR ':'
# define PATH_LISTSEP_STR ":"
# define PATH_WRONGSLASH_CHAR '\\'
# define PATH_WRONGSLASH_STR "\\"
#endif

/**
    Create a new path structure from a string
*/
struct FilePath *ospath_new(const char *path){
    struct FilePath *fp;
    fp = ospath_new_noclean(path);

#ifdef DO_FIXSLASHES
    ospath_fixslash(fp->path);
#endif

    ospath_cleanup(fp);

    //D(fp);

    return fp;
}


/// Create but with no 'cleanup', and no fixing of / vs \.
struct FilePath *ospath_new_noclean(const char *path){
    struct FilePath *fp = (struct FilePath *)MALLOC(sizeof(struct FilePath));
    STRNCPY(fp->path,path,PATH_MAX);
    assert(strcmp(fp->path,path)==0);
#ifdef WINPATHS
    //X(fp->path);
    ospath_extractdriveletter(fp);
#endif

    return fp;
}

struct FilePath *ospath_new_expand_env(const char *path, GetEnvFn *getenvptr){
    struct FilePath *fp;

    char *pathnew = env_subst(path,getenvptr);
    fp = ospath_new(pathnew);
    FREE(pathnew);

    return fp;
}


/**
    This function will serve to allow #include-style file paths
    to be specified with platform-independent forward slashes then
    translated into the local filesystem format for subsequent use.

    This method should be identical to ospath_new on posix, right?

    @NOTE: on windows, we also want:
                    C:dir/file --> c:$PWD\dir\file
                      e:/hello --> e:\hello
                     here/i/am --> here\i\am

    @NOTE:
    A path-search function should create full file paths by
    appending relative file to each component of the search path
    then performing a callback on each one to determine if the
    match is OK or not.
*/
struct FilePath *ospath_new_from_posix(const char *posixpath){
    struct FilePath *fp;
    fp = ospath_new_noclean(posixpath);

#ifdef DO_FIXSLASHES
    ospath_fixslash(fp->path);
#endif

    //X(fp->path);

    ospath_cleanup(fp);

    return fp;
}

void ospath_free(struct FilePath *fp){
    FREE(fp);
}

void ospath_free_str(char *str){
    FREE(str);
}


#ifdef DO_FIXSLASHES
void ospath_fixslash(char *path){

    char *p;
    char temp[PATH_MAX];
    int startslash;
    int endslash;
    STRTOKVAR(nexttok);

    STRNCPY(temp,path,PATH_MAX);

    //X(path);

    startslash = (strlen(temp) > 0 && temp[0] == PATH_WRONGSLASH_CHAR);
    endslash = (strlen(temp) > 1 && temp[strlen(temp) - 1] == PATH_WRONGSLASH_CHAR);

    //V(startslash);
    //V(endslash);

    // reset fp->path as required.
    STRNCPY(path, (startslash ? PATH_SEPARATOR_STR : ""), PATH_MAX);

    //M("STARTING STRTOK");
    for(p = STRTOK(temp, PATH_WRONGSLASH_STR,nexttok);
            p!=NULL;
            p = STRTOK(NULL,PATH_WRONGSLASH_STR,nexttok)
    ){
        // add a separator if we've already got some stuff
        if(
            strlen(path) > 0
            && path[strlen(path) - 1] != PATH_SEPARATOR_CHAR
        ){
            STRCAT(path,PATH_SEPARATOR_STR);
        }

        STRCAT(path,p);
    }
    //M("FINISHED STRTOK");

    // put / on end as required, according to what the starting path had
    if(endslash && (strlen(path) > 0 ? (path[strlen(path) - 1] != PATH_SEPARATOR_CHAR) : 1))
    {
        //M("adding endslash!");

        STRCAT(path, PATH_SEPARATOR_STR);
    }

    //X(path);
}
#endif

struct FilePath *ospath_getcwd(void){
    struct FilePath *fp = (struct FilePath *)MALLOC(sizeof(struct FilePath));
    char *cwd;

    // get current working directory
    cwd = (char *)GETCWD(NULL, 0);

    // create new path with resolved working directory
    fp = ospath_new_noclean(cwd != NULL ? cwd : ".");

    D(fp);

    return fp;
}

/**
    Use getenv() function to retrieve HOME path, or if not set, use
    the password database and try to retrieve it that way (???)
*/
struct FilePath *ospath_gethomepath(void){

    const char *pfx = (const char *)getenv("HOME");
    struct FilePath *fp;

#ifndef __WIN32__
# ifdef TRY_GETPWUID
    struct passwd *pw;

    if(pfx==NULL){
         pw = (struct passwd*)getpwuid(getuid());

        if(pw){
            pfx = pw->pw_dir;
        }
    }
# endif
#endif

    // create path object from HOME, but don't compress it
    // (because that would lead to an infinite loop)
    fp = ospath_new_noclean(pfx ? pfx : "");

#ifdef DO_FIXSLASHES
    ospath_fixslash(fp->path);
#endif

    return fp;
}

#ifdef WINPATHS
void ospath_extractdriveletter(struct FilePath *fp)
{
    char *p;
    //M("SOURCE");
    //X(fp->path);
    //fprintf(stderr,"CHAR 1 = %c\n",fp->path[1]);

    // extract the drive the path resides on...
    if(strlen(fp->path) >= 2 && fp->path[1] == ':')
    {
        STRNCPY(fp->drive,fp->path,2);
        fp->drive[2]='\0';
        for(p=fp->path+2; *p!='\0'; ++p){
            *(p-2)=*p;
        }
        *(p-2)='\0';
    }else{
        STRNCPY(fp->drive,"",DRIVEMAX);
    }
    //M("RESULT");
    //X(fp->path);
    //X(fp->drive);
}
#endif

void ospath_cleanup(struct FilePath *fp){
    char path[PATH_MAX];
    char *p;
    struct FilePath *home;
    struct FilePath *working;
    struct FilePath *parent;
    STRTOKVAR(nexttok);

    // compress the path, and resolve ~
    int startslash = (strlen(fp->path) > 0 && fp->path[0] == PATH_SEPARATOR_CHAR);
    int endslash = (strlen(fp->path) > 1 && fp->path[strlen(fp->path) - 1] == PATH_SEPARATOR_CHAR);

    //fprintf(stderr,"FS ON START = %d\n",startslash);
    //fprintf(stderr,"FS ON END   = %d\n",endslash);
    //fprintf(stderr,"FIRST CHAR = %c\n",fp->path[0]);

    home = ospath_gethomepath();

    // create a copy of fp->path.
    STRCPY(path, fp->path);

    // reset fp->path as required.
    STRCPY(fp->path, (startslash ? PATH_SEPARATOR_STR : ""));

    D(fp);
    X(path);

    // split path into it tokens, using STRTOK which is NOT reentrant
    // so be careful!

    //M("STARTING STRTOK");
    for(p = STRTOK(path, PATH_SEPARATOR_STR,nexttok);
            p!=NULL;
            p = STRTOK(NULL,PATH_SEPARATOR_STR,nexttok)
    ){
        //M("NEXT TOKEN");
        //X(p);
        //X(path+strlen(p)+1);
        if(strcmp(p, "~")==0){

            if(p == path){ // check that the ~ is the first character in the path
                if(ospath_isvalid(home)){
                    ospath_copy(fp,home);
                    continue;
                }else{
                    E("HOME does not resolve to valid path");
                }
            }else{
                E("A tilde (~) present as a component in a file path must be at the start!");
            }
        }else if(strcmp(p, ".") == 0){

            if(p==path){// start of path:
                M("EXPANDING LEADING '.' IN PATH");
                X(path);

                working = ospath_getcwd();

                D(working);
#ifdef WINPATHS
                X(working->drive);
#endif
                X(p);
                X(path);

                ospath_copy(fp,working);


                D(fp);
                X(p);
                //X(path+strlen(p)+1);

                //ospath_free(working);
                continue;
            }else{// later in the path: just skip it
                M("SKIPPING '.' IN PATH");
                continue;
            }

        }else if(strcmp(p, "..") == 0){
            M("GOING TO PARENT");
            parent = ospath_getparent(fp);
            if(ospath_isvalid(parent)){
                ospath_copy(fp,parent);
            }
            //ospath_free(parent);
            continue;
        }

        // add a separator if we've already got some stuff
        if(
            strlen(fp->path) > 0
            && fp->path[strlen(fp->path) - 1] != PATH_SEPARATOR_CHAR
        ){
            STRCAT(fp->path,PATH_SEPARATOR_STR);
        }

        // add the present path component
        STRCAT(fp->path, p);
    }
    //M("FINISHED STRTOK");

    // put / on end as required, according to what the starting path had
    if(endslash && (strlen(fp->path) > 0 ? (fp->path[strlen(fp->path) - 1] != PATH_SEPARATOR_CHAR) : 1))
    {
        STRCAT(fp->path, PATH_SEPARATOR_STR);
    }
}


int ospath_isvalid(struct FilePath *fp){
    //if(fp==NULL) return 0;
    return strlen(fp->path) > 0 ? 1 : 0;
}


char *ospath_str(struct FilePath *fp){
    char *s;
#ifdef WINPATHS
    s = (char *)MALLOC(sizeof(char)*(strlen(fp->drive)+strlen(fp->path) +1) );
    STRCPY(s,fp->drive);
    STRCAT(s,fp->path);
#else
    s = MALLOC(sizeof(char)*(strlen(fp->path)+1));
    STRCPY(s,fp->path);
#endif
    return s;
}

void ospath_strcpy(struct FilePath *fp, char *dest, int destsize){
#ifdef WINPATHS
    STRNCPY(dest,fp->drive,destsize);
    STRNCAT(dest,fp->path,destsize-strlen(dest));
#else
    STRNCPY(dest,fp->path,destsize);
#endif
}


void ospath_strcat(struct FilePath *fp, char *dest, int destsize){
    int remaining = destsize - strlen(dest);
    V(remaining);
#ifdef WINPATHS
    STRNCAT(dest,fp->drive,remaining);
    STRNCAT(dest,fp->path,remaining-strlen(dest));
#else
    STRNCAT(dest,fp->path,remaining);
#endif
    D(fp);
}

void ospath_fwrite(struct FilePath *fp, FILE *dest){
#ifdef WINPATHS
    fprintf(dest,"%s%s",fp->drive,fp->path);
#else
    fprintf(dest,"%s",fp->path);
#endif
}

unsigned ospath_length(struct FilePath *fp){
#ifdef  WINPATHS
    // we've already validated this path, so it's on to just add it up
    // (unless someone has been tinkering with the internal structure here)
    return (unsigned) (strlen(fp->drive) + strlen(fp->path));
#else
    return (unsigned) (strlen(fp->path));
#endif
}

struct FilePath *ospath_getparent(struct FilePath *fp)
{
    int length;
    int offset;
    char *pos;
    int len1;
    char sub[PATH_MAX];
    struct FilePath *fp1, *fp2;

    D(fp);

    if(strlen(fp->path) == 0){
        fp1 = ospath_getcwd();
        fp2 = ospath_getparent(fp1);
        ospath_free(fp1);
        return fp2;
    }else if(ospath_isroot(fp)){
        // stay at root
        return ospath_new("/");
    }

    // reverse find a / ignoring the end / if it exists.
    /// FIXME
    length = strlen(fp->path);
    offset = (
            fp->path[length - 1] == PATH_SEPARATOR_CHAR // last char is slash?
            && length > 1 // and more than just leading slash...
        ) ? length - 1 : length; // then remove last char

    for(pos = fp->path + offset - 1; *pos!=PATH_SEPARATOR_CHAR && pos>=fp->path; --pos){
        //fprintf(stderr,"CURRENT CHAR: %c\n",*pos);
    }

    len1 = (int)pos - (int)fp->path;
    V(len1);
    //fprintf(stderr,"POS = %d\n",len1);

    if(*pos==PATH_SEPARATOR_CHAR){
#ifdef WINPATHS
        STRCPY(sub,fp->drive);
        STRNCAT(sub,fp->path,len1);
#else
        STRNCPY(sub,fp->path,len1);
        sub[len1]='\0';
#endif
        X(sub);
        if(strcmp(sub,"")==0){
            M("DIRECTORY IS EMPTY");
            STRCAT(sub,PATH_SEPARATOR_STR);
        }
    }else{
        E("NO PARENT DIR");
        return ospath_new_noclean(fp->path);
    }

    fp1 = ospath_new_noclean(sub);
    D(fp1);
    return fp1;
}

struct FilePath *ospath_getparentatdepthn(struct FilePath *fp, unsigned depth)
{
    int startslash;
    char path[PATH_MAX];
    char *temp;
    char *p;
    STRTOKVAR(nexttok);
#ifdef WINPATHS
    char temp2[PATH_MAX];
#endif

    if(
        !ospath_isvalid(fp)
        || depth >= ospath_depth(fp)
    ){
        return fp;
    }

    // create FilePath object to parent object at depth N relative to this
    // path object.
    startslash = (strlen(fp->path) > 0 && fp->path[0] == PATH_SEPARATOR_CHAR);

    // create a copy of fp->path.
    STRCPY(path, fp->path);

    // reset fp->path as required.
    temp = startslash ? PATH_SEPARATOR_STR : "";

    // split path into it tokens.
    //M("STARTING STRTOK");
    p = STRTOK(path, PATH_SEPARATOR_STR, nexttok);

    while(p && depth > 0)
    {
        if(strlen(temp) > 0 && temp[strlen(temp) - 1] != PATH_SEPARATOR_CHAR)
        {
            strcat(temp,PATH_SEPARATOR_STR);
        }

        STRCAT(temp,p);
        --depth;

        p = STRTOK(NULL, PATH_SEPARATOR_STR, nexttok);
    }
    //M("FINISHED STRTOK");

    // put / on end as required
    if(strlen(temp) > 0 ? (temp[strlen(temp) - 1] != PATH_SEPARATOR_CHAR) : 1)
    {
        strcat(temp,PATH_SEPARATOR_STR);
    }

#ifdef WINPATHS
    STRCPY(temp2,fp->drive);
    STRCAT(temp2,temp);
    return ospath_new_noclean(temp2);
#else
    return ospath_new_noclean(temp);
#endif
}

char *ospath_getbasefilename(struct FilePath *fp){
    char *temp;
    unsigned length, offset;
    char *pos;

    if(strlen(fp->path) == 0){
        // return empty name.
        return "";
    }

    if(fp->path[strlen(fp->path)-1]==PATH_SEPARATOR_CHAR){
        return NULL;
    }

    // reverse find '/' but DON'T ignore a trailing slash
    // (this is changed from the original implementation)
    length = strlen(fp->path);
    offset = length;

    pos = strrchr(fp->path, PATH_SEPARATOR_CHAR); /* OFFSET! */

    // extract filename given position of find / and return it.
    if(pos != NULL){
        unsigned length1 = length - ((pos - fp->path) + 1);
        temp = (char *)MALLOC(sizeof(char)*length1);

        V(length1);
        STRNCPY(temp, pos + 1, length1);
        return temp;
    }else{
        temp = (char *)MALLOC(sizeof(char)*length);
        STRNCPY(temp, fp->path, length);
        return temp;
    }
}

char *ospath_getfilestem(struct FilePath *fp){
    char *temp;
    char *pos;

    if(!ospath_isvalid(fp)){
        return NULL;
    }

    temp = ospath_getbasefilename(fp);
    if(temp==NULL){
        // it's a directory
        return NULL;
    }

    pos = strrchr(temp,'.');

    if(pos==NULL || pos==temp){
        // no extension, or a filename starting with '.'
        // -- return the whole filename
        return temp;
    }

    // remove extension.
    *pos = '\0';

    return temp;
}

char *ospath_getfileext(struct FilePath *fp){
    char *temp, *temp2, *pos;
    int len1;

    if(!ospath_isvalid(fp)){
        return NULL;
    }

    temp = ospath_getbasefilename(fp);
    if(temp==NULL){
        // it's a directory
        return NULL;
    }

    // make sure there is no / on the end.
    /// FIXME: is this good policy, removing a trailing slash?
    if(temp[strlen(temp) - 1] == PATH_SEPARATOR_CHAR){
        temp[strlen(temp)-1] = '\0';
    }

    pos = strrchr(temp,'.');

    if(pos != NULL && pos!=temp){
        // extract extension.
        len1 = temp + strlen(temp) - pos + 1;
        temp2 = (char *)MALLOC(sizeof(char)*len1);
        STRNCPY(temp2, pos, len1);
    }else{
        // no extension
        temp2 = NULL;
    }
    FREE(temp);
    return temp2;
}

int ospath_isroot(struct FilePath *fp)
{
    if(!ospath_isvalid(fp))
    {
        return 0;
    }

    return fp->path == PATH_SEPARATOR_STR ? 1 : 0;
}

unsigned ospath_depth(struct FilePath *fp){
    unsigned length;
    unsigned depth;
    unsigned i;

    length = strlen(fp->path);
    depth = 0;

    for(i = 0; i < length; i++){
        if(fp->path[i] == PATH_SEPARATOR_CHAR){
            ++depth;
        }
    }

    if(
        depth > 0
        && length > 0
        && fp->path[length - 1] == PATH_SEPARATOR_CHAR
    ){
        // PATH_SEPARATOR_CHAR on the end, reduce count by 1
        --depth;
    }

    return depth;
}

struct FilePath *ospath_root(struct FilePath *fp){
#ifdef WINPATHS
    //M("WIN ROOT");
    char *temp;
    struct FilePath *r;

    if(strlen(fp->drive)){
        temp = (char *)MALLOC(sizeof(char)*strlen(fp->drive)+1);
        STRCPY(temp,fp->drive);
        STRCAT(temp,PATH_SEPARATOR_STR);
        X(temp);
        r = ospath_new(temp);
        FREE(temp);
    }else{
        r = ospath_new(fp->path);
    }
    return r;
#else
    //M("JUST RETURNING PATH SEP");
    return ospath_new(PATH_SEPARATOR_STR);
#endif
}

struct FilePath *ospath_getdir(struct FilePath *fp){
    char *pos;
    char s[PATH_MAX];

    pos = strrchr(fp->path,PATH_SEPARATOR_CHAR);
    if(pos==NULL){
        return ospath_new(".");
    }
#ifdef WINPATHS
    strncpy(s,fp->drive,PATH_MAX);
    strncat(s,fp->path,pos - fp->path);
#else
    strncpy(s,fp->path,pos - fp->path);
#endif
    return ospath_new(s);
}

int ospath_cmp(struct FilePath *fp1, struct FilePath *fp2){
    char temp[2][PATH_MAX];
#ifdef WINPATHS
    char *p;
    struct FilePath *fp;
#endif

    if(!ospath_isvalid(fp1)){
        if(!ospath_isvalid(fp2)){
            return 0;
        }else{
            return -1;
        }
    }else if(!ospath_isvalid(fp2)){
        return 1;
    }

    // now, both are valid...
    //M("BOTH ARE VALID");

    //Check that paths both have drives, if applic.
#ifdef WINPATHS
    if(strcmp(fp1->drive,"")==0){
        M("PATH IS MISSING DRIVE LETTER");
        D(fp1);
        fp = ospath_getcwd();
        assert(strlen(fp->drive)!=0);
        X(fp->drive);
        STRCPY(temp[0],fp->drive);
        ospath_free(fp);
    }else{
        STRCPY(temp[0],fp1->drive);
    }

    if(strcmp(fp2->drive,"")==0){
        M("PATH IS MISSING DRIVE LETTER");
        D(fp2);
        fp = ospath_getcwd();
        assert(strlen(fp->drive)!=0);
        X(fp->drive);
        STRCPY(temp[1],fp->drive);
        ospath_free(fp);
    }else{
        STRCPY(temp[1],fp2->drive);
    }

    STRCAT(temp[0],fp1->path);
    STRCAT(temp[1],fp2->path);
#else
    STRCPY(temp[0], fp1->path);
    STRCPY(temp[1], fp2->path);
#endif

#ifdef WINPATHS
    X(temp[0]);
    for(p=temp[0];*p!='\0';++p){
        *p=tolower(*p);
        //C(*p);
    }
    X(temp[1]);
    for(p=temp[1];*p!='\0';++p){
        *p=tolower(*p);
        //C(*p);
    }
    X(temp[0]);
    X(temp[1]);
#endif

    // we will count two paths that different only in a trailing slash to be the *same*
    // so we add trailing slashes to both now:
    if(temp[0][strlen(temp[0]) - 1] != PATH_SEPARATOR_CHAR){
        STRCAT(temp[0],PATH_SEPARATOR_STR);
    }

    if(temp[1][strlen(temp[1]) - 1] != PATH_SEPARATOR_CHAR){
        STRCAT(temp[1],PATH_SEPARATOR_STR);
    }

    //X(temp[0]);
    //X(temp[1]);

    return strcmp(temp[0],temp[1]);
}

struct FilePath *ospath_concat(struct FilePath *fp1, struct FilePath *fp2){

    struct FilePath *fp;
    char temp[2][PATH_MAX];
    char temp2[PATH_MAX];
    struct FilePath *r;

    fp = (struct FilePath *)MALLOC(sizeof(struct FilePath));

    if(!ospath_isvalid(fp1)){
        if(ospath_isvalid(fp2)){
            ospath_copy(fp,fp2);
        }else{
            // both invalid
            ospath_copy(fp,fp1);
        }
        return fp;
    }

    if(!ospath_isvalid(fp2)){
        ospath_copy(fp,fp1);
        return fp;
    }

    // not just a copy of one or the other...
    ospath_free(fp);

    // now, both paths are valid...

#ifdef WINPATHS
    STRNCPY(temp[0],fp1->drive,PATH_MAX);
    STRNCAT(temp[0],fp1->path,PATH_MAX-strlen(temp[0]));
#else
    STRNCPY(temp[0], fp1->path,PATH_MAX);
#endif

    STRNCPY(temp[1], fp2->path,PATH_MAX);

    // make sure temp has a / on the end.
    if(temp[0][strlen(temp[0]) - 1] != PATH_SEPARATOR_CHAR)
    {
        STRNCAT(temp[0],PATH_SEPARATOR_STR,PATH_MAX-strlen(temp[0]));
    }

#ifdef DO_FIXSLASHES
    ospath_fixslash(temp[0]);
    ospath_fixslash(temp[1]);
#endif

    //V(strlen(temp[0]));
    //X(temp[0]);
    //V(strlen(temp[1]));
    //X(temp[1]);

    // make sure rhs path has NOT got a / at the start.
    if(temp[1][0] == PATH_SEPARATOR_CHAR){
        return NULL;
    }

    // create a new path object with the two path strings appended together.
    STRNCPY(temp2,temp[0],PATH_MAX);
    STRNCAT(temp2,temp[1],PATH_MAX-strlen(temp2));
    //V(strlen(temp2));
    //X(temp2);
    r = ospath_new_noclean(temp2);
    D(r);

    /* ospath_cleanup(r);*/
    return r;
}

void ospath_append(struct FilePath *fp, struct FilePath *fp1){
    char *p;
    char temp[2][PATH_MAX];
    struct FilePath fp2;

    ospath_copy(&fp2,fp1);
#ifdef DO_FIXSLASHES
    ospath_fixslash(fp2.path);
#endif

    if(!ospath_isvalid(&fp2)){
        M("fp1 invalid");
        return;
    }

    if(!ospath_isvalid(fp) && ospath_isvalid(&fp2)){
        // set this object to be the same as the rhs
        M("fp invalid");
        ospath_copy(fp,&fp2);
#ifdef DO_FIXSLASHES
        ospath_fixslash(fp->path);
#endif
        return;
    }

    X(fp->path);
    X(fp2.path);

    // both paths are valid...
    //temp[0] = CALLOC(1+strlen(fp->path), sizeof(char));
    STRNCPY(temp[0], fp->path, PATH_MAX);
    //temp[1] = CALLOC(strlen(fp2.path), sizeof(char));
    STRNCPY(temp[1], fp2.path, PATH_MAX);

    X(temp[0]);
    X(temp[1]);

    // make sure temp has a / on the end.
    if(temp[0][strlen(temp[0]) - 1] != PATH_SEPARATOR_CHAR)
    {
        STRCAT(temp[0],PATH_SEPARATOR_STR);
    }

    // make sure rhs path has NOT got a / at the start.
    if(temp[1][0] == PATH_SEPARATOR_CHAR){
        for(p=temp[1]+1; *p != '\0'; ++p){
            *(p-1)=*p;
        }
        *(p-1)='\0';
    }

    X(temp[0]);
    X(temp[1]);

    // create new path string.
    STRNCPY(fp->path,temp[0], PATH_MAX);
    STRNCAT(fp->path,temp[1], PATH_MAX-strlen(fp->path));

    X(fp->path);

    //FREE(temp[0]);
    //M("Freed temp[0]");
    //FREE(temp[1]);
    //M("Freed temp[1]");

    D(fp);
    ospath_cleanup(fp);
}

void ospath_copy(struct FilePath *dest, struct FilePath *src){
    STRCPY(dest->path,src->path);
#ifdef WINPATHS
    STRCPY(dest->drive,src->drive);
#endif
}

void ospath_debug(struct FilePath *fp){
#ifdef WINPATHS
    fprintf(stderr,"{\"%s\",\"%s\"}\n",fp->drive,fp->path);
#else
    fprintf(stderr,"{\"%s\"}\n",fp->path);
#endif
}

FILE *ospath_fopen(struct FilePath *fp, const char *mode){
    char s[PATH_MAX];
    if(!ospath_isvalid(fp)){
        E("Invalid path");
        return NULL;
    }
    ospath_strcpy(fp,s,PATH_MAX);
    FILE *f = fopen(s,mode);
    return f;
}

//------------------------
// SEARCH PATH FUNCTIONS

struct FilePath **ospath_searchpath_new(const char *path){
    char *p;
    char *list[LISTMAX];
    unsigned n=0;
    char *c;
    unsigned i;
    struct FilePath **pp;
    STRTOKVAR(nexttok);

    char path1[PATH_MAX];
    strncpy(path1,path,PATH_MAX);

    X(path1);
    X(PATH_LISTSEP_STR);

    V(strlen(path1));
    V(strlen(PATH_LISTSEP_STR));

    /*
    c = strstr(path,PATH_LISTSEP_CHAR);
    if(c==NULL){
        E("NO TOKEN FOUND");
    }
    */

    p=STRTOK(path1,PATH_LISTSEP_STR,nexttok);
    X(p);
    for(; p!= NULL; p=STRTOK(NULL,PATH_LISTSEP_STR,nexttok)){
        c = (char *)MALLOC(sizeof(char)*strlen(p));
        X(p);
        STRCPY(c,p);
        if(n>=LISTMAX){
            E("IGNORING SOME PATH COMPONENTS");
            break;
        }
        list[n++]=c;
    }

    /*
    for(i=0;i<n;++i){
        X(list[i]);
    }
    V(n);
    */

    pp = (struct FilePath **)MALLOC(sizeof(struct FilePath*)*(n+1));
    for(i=0; i<n; ++i){
        //V(i);
        //X(list[i]);
        pp[i] = ospath_new_noclean(list[i]);
        //D(pp[i]);
    }
    pp[n] = NULL;

    for(i=0;i<n;++i){
#ifdef DO_FIXSLASHES
        ospath_fixslash(pp[i]->path);
#endif
        D(pp[i]);
    }

    return pp;
}

void ospath_searchpath_free(struct FilePath **searchpath){
    struct FilePath **p;
    for(p=searchpath; *p!=NULL; ++p){
        ospath_free(*p);
    }
    FREE(searchpath);
}

struct FilePath *ospath_searchpath_iterate(
        struct FilePath **searchpath
        , FilePathTestFn *testfn
        , void *searchdata
){
    struct FilePath **p;

    p = searchpath;

    M("SEARCHING IN...");
    for(p=searchpath; *p!=NULL; ++p){
        D(*p);
    }

    for(p=searchpath; *p!=NULL; ++p){
        D(*p);
        if((*testfn)(*p,searchdata)){
            return *p;
        }
    }
    return NULL;
}