CommandLineToArgvA.h

#ifndef COMMANDLINETOARGVA_H_INCLUDED
#define COMMANDLINETOARGVA_H_INCLUDED

/*************************************************************************
 * CommandLineToArgvA            [SHELL32.@]
 *
 * MODIFIED FROM https://www.winehq.org/ project
 * We must interpret the quotes in the command line to rebuild the argv
 * array correctly:
 * - arguments are separated by spaces or tabs
 * - quotes serve as optional argument delimiters
 *   '"a b"'   -> 'a b'
 * - escaped quotes must be converted back to '"'
 *   '\"'      -> '"'
 * - consecutive backslashes preceding a quote see their number halved with
 *   the remainder escaping the quote:
 *   2n   backslashes + quote -> n backslashes + quote as an argument delimiter
 *   2n+1 backslashes + quote -> n backslashes + literal quote
 * - backslashes that are not followed by a quote are copied literally:
 *   'a\b'     -> 'a\b'
 *   'a\\b'    -> 'a\\b'
 * - in quoted strings, consecutive quotes see their number divided by three
 *   with the remainder modulo 3 deciding whether to close the string or not.
 *   Note that the opening quote must be counted in the consecutive quotes,
 *   that's the (1+) below:
 *   (1+) 3n   quotes -> n quotes
 *   (1+) 3n+1 quotes -> n quotes plus closes the quoted string
 *   (1+) 3n+2 quotes -> n+1 quotes plus closes the quoted string
 * - in unquoted strings, the first quote opens the quoted string and the
 *   remaining consecutive quotes follow the above rule.
 */

LPSTR* WINAPI CommandLineToArgvA(LPSTR lpCmdline, int* numargs)
{
    DWORD argc;
    LPSTR  *argv;
    LPSTR s;
    LPSTR d;
    LPSTR cmdline;
    int qcount,bcount;

    if(!numargs || *lpCmdline==0)
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return NULL;
    }

    /* --- First count the arguments */
    argc=1;
    s=lpCmdline;
    /* The first argument, the executable path, follows special rules */
    if (*s=='"')
    {
        /* The executable path ends at the next quote, no matter what */
        s++;
        while (*s)
            if (*s++=='"')
                break;
    }
    else
    {
        /* The executable path ends at the next space, no matter what */
        while (*s && *s!=' ' && *s!='\t')
            s++;
    }
    /* skip to the first argument, if any */
    while (*s==' ' || *s=='\t')
        s++;
    if (*s)
        argc++;

    /* Analyze the remaining arguments */
    qcount=bcount=0;
    while (*s)
    {
        if ((*s==' ' || *s=='\t') && qcount==0)
        {
            /* skip to the next argument and count it if any */
            while (*s==' ' || *s=='\t')
                s++;
            if (*s)
                argc++;
            bcount=0;
        }
        else if (*s=='\\')
        {
            /* '\', count them */
            bcount++;
            s++;
        }
        else if (*s=='"')
        {
            /* '"' */
            if ((bcount & 1)==0)
                qcount++; /* unescaped '"' */
            s++;
            bcount=0;
            /* consecutive quotes, see comment in copying code below */
            while (*s=='"')
            {
                qcount++;
                s++;
            }
            qcount=qcount % 3;
            if (qcount==2)
                qcount=0;
        }
        else
        {
            /* a regular character */
            bcount=0;
            s++;
        }
    }

    /* Allocate in a single lump, the string array, and the strings that go
     * with it. This way the caller can make a single LocalFree() call to free
     * both, as per MSDN.
     */
    argv = (char**) LocalAlloc(LMEM_FIXED, (argc+1)*sizeof(LPSTR)+(strlen(lpCmdline)+1)*sizeof(char));
    if (!argv)
        return NULL;
    cmdline=(LPSTR)(argv+argc+1);
    strcpy(cmdline, lpCmdline);

    /* --- Then split and copy the arguments */
    argv[0]=d=cmdline;
    argc=1;
    /* The first argument, the executable path, follows special rules */
    if (*d=='"')
    {
        /* The executable path ends at the next quote, no matter what */
        s=d+1;
        while (*s)
        {
            if (*s=='"')
            {
                s++;
                break;
            }
            *d++=*s++;
        }
    }
    else
    {
        /* The executable path ends at the next space, no matter what */
        while (*d && *d!=' ' && *d!='\t')
            d++;
        s=d;
        if (*s)
            s++;
    }
    /* close the executable path */
    *d++=0;
    /* skip to the first argument and initialize it if any */
    while (*s==' ' || *s=='\t')
        s++;
    if (!*s)
    {
        /* There are no parameters so we are all done */
        argv[argc]=NULL;
        *numargs=argc;
        return argv;
    }

    /* Split and copy the remaining arguments */
    argv[argc++]=d;
    qcount=bcount=0;
    while (*s)
    {
        if ((*s==' ' || *s=='\t') && qcount==0)
        {
            /* close the argument */
            *d++=0;
            bcount=0;

            /* skip to the next one and initialize it if any */
            do {
                s++;
            } while (*s==' ' || *s=='\t');
            if (*s)
                argv[argc++]=d;
        }
        else if (*s=='\\')
        {
            *d++=*s++;
            bcount++;
        }
        else if (*s=='"')
        {
            if ((bcount & 1)==0)
            {
                /* Preceded by an even number of '\', this is half that
                 * number of '\', plus a quote which we erase.
                 */
                d-=bcount/2;
                qcount++;
            }
            else
            {
                /* Preceded by an odd number of '\', this is half that
                 * number of '\' followed by a '"'
                 */
                d=d-bcount/2-1;
                *d++='"';
            }
            s++;
            bcount=0;
            /* Now count the number of consecutive quotes. Note that qcount
             * already takes into account the opening quote if any, as well as
             * the quote that lead us here.
             */
            while (*s=='"')
            {
                if (++qcount==3)
                {
                    *d++='"';
                    qcount=0;
                }
                s++;
            }
            if (qcount==2)
                qcount=0;
        }
        else
        {
            /* a regular character */
            *d++=*s++;
            bcount=0;
        }
    }
    *d='\0';
    argv[argc]=NULL;
    *numargs=argc;

    return argv;
}

#endif // COMMANDLINETOARGVA_H_INCLUDED