stringOps.C

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
     \\/     M anipulation  | Copyright (C) 2017 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM 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 3 of the License, or
    (at your option) any later version.

    OpenFOAM 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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "stringOps.H"
#include "typeInfo.H"
#include "OSspecific.H"
#include "etcFiles.H"
#include "StringStream.H"
#include <cctype>

// * * * * * * * * * * * * * * * Local Functions * * * * * * * * * * * * * * //

namespace Foam
{

// Expand a leading <tag>/
// Convenient for frequently used directories
//
//   <etc>/        => user/group/other OpenFOAM directory
//   <case>/       => FOAM_CASE directory
//   <constant>/   => FOAM_CASE/constant directory
//   <system>/     => FOAM_CASE/system directory
static void expandLeadingTag(std::string& s, const char b, const char e)
{
    if (s[0] != b)
    {
        return;
    }

    auto delim = s.find(e);
    if (delim == std::string::npos)
    {
        return;  // Error: no closing delim - ignore expansion
    }

    fileName file;

    const char nextC = s[++delim];

    // Require the following character to be '/' or the end of string.
    if (nextC)
    {
        if (nextC != '/')
        {
            return;
        }

        file.assign(s.substr(delim + 1));
    }

    const std::string tag(s, 1, delim-2);

    // Note that file is also allowed to be an empty string.

    if (tag == "etc")
    {
        s = findEtcFile(file);
    }
    else if (tag == "case")
    {
        s = fileName(getEnv("FOAM_CASE"))/file;
    }
    else if (tag == "constant" || tag == "system")
    {
        s = fileName(Foam::getEnv("FOAM_CASE"))/tag/file;
    }
}


// Expand a leading tilde
//   ~/        => home directory
//   ~OpenFOAM => user/group/other OpenFOAM directory
//   ~user     => home directory for specified user
static void expandLeadingTilde(std::string& s)
{
    if (s[0] != '~')
    {
        return;
    }

    std::string user;
    fileName file;

    const auto slash = s.find('/');
    if (slash == std::string::npos)
    {
        user = s.substr(1);
    }
    else
    {
        user = s.substr(1, slash - 1);
        file = s.substr(slash + 1);
    }

    // NB: be a bit lazy and expand ~unknownUser as an
    // empty string rather than leaving it untouched.
    // otherwise add extra test

    if (user == "OpenFOAM")
    {
        s = findEtcFile(file);
    }
    else
    {
        s = home(user)/file;
    }
}


// Expand leading contents:  "./", "~..", "<tag>/"
static void expandLeading(std::string& s)
{
    if (s.empty())
    {
        return;
    }

    switch (s[0])
    {
        case '.':
        {
            // Expand a lone '.' and an initial './' into cwd
            if (s.size() == 1)
            {
                s = cwd();
            }
            else if (s[1] == '/')
            {
                s.std::string::replace(0, 1, cwd());
            }
            break;
        }
        case '<':
        {
            expandLeadingTag(s, '<', '>');
            break;
        }
        case '~':
        {
            expandLeadingTilde(s);
            break;
        }
    }
}

} // end of namespace Foam


//! \cond fileScope
//  Find the type/position of the ":-" or ":+" alternative values
//  Returns 0, '-', '+' corresponding to not-found or ':-' or ':+'
static inline int findParameterAlternative
(
    const std::string& s,
    std::string::size_type& pos,
    std::string::size_type endPos
)
{
    while (pos != std::string::npos)
    {
        pos = s.find(':', pos);
        if (pos != std::string::npos)
        {
            if (pos < endPos)
            {
                // in-range: check for '+' or '-' following the ':'
                const int altType = s[pos+1];
                if (altType == '+' || altType == '-')
                {
                    return altType;
                }

                ++pos;    // unknown/unsupported - continue at next position
            }
            else
            {
                // out-of-range: abort
                pos = std::string::npos;