Function raw_command_length

src/engine/execnt.cpp:637–694

 */

static int32_t raw_command_length( char const * command )
{
    char const * p;
    char const * escape = 0;
    char inquote = 0;
    char const * newline = 0;

    /* Skip leading whitespace. */
    while ( isspace( *command ) )
        ++command;

    p = command;

    /* Look for newlines and unquoted I/O redirection. */
    do
    {
        p += strcspn( p, "\n\"'<>|\\" );
        switch ( *p )
        {
        case '\n':
            /* If our command contains non-whitespace content split over
             * multiple lines we can not execute it directly.
             */
            newline = p;
            while ( isspace( *++p ) );
            if ( *p ) return -1;
            break;

        case '\\':
            escape = escape && escape == p - 1 ? 0 : p;
            ++p;
            break;

        case '"':
        case '\'':
            if ( escape && escape == p - 1 )
                escape = 0;
            else if ( inquote == *p )
                inquote = 0;
            else if ( !inquote )
                inquote = *p;
            ++p;
            break;

        case '<':
        case '>':
        case '|':
            if ( !inquote )
                return -1;
            ++p;
            break;
        }
    }
    while ( *p );

    /* Return the number of characters the command will occupy. */
    return int32_t(( newline ? newline : p ) - command);
}