CLI: untieStdIO() to avoid unwanted implicit flush() calls on std::cout → less write() calls
/**
* Relational pipes
* Copyright © 2018 František Kučera (Frantovo.cz, GlobalCode.info)
*
* 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 3 of the License, 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, see <http://www.gnu.org/licenses/>.
*/
#include <cstdlib>
#include <fstream>
#include <memory>
#include <regex>
#include <algorithm>
#include <unistd.h>
#include <relpipe/writer/RelationalWriter.h>
#include <relpipe/writer/RelpipeWriterException.h>
#include <relpipe/writer/Factory.h>
#include <relpipe/writer/TypeId.h>
#include <relpipe/cli/CLI.h>
using namespace relpipe::cli;
using namespace relpipe::writer;
/**
* see https://hg.frantovo.cz/sql-api/file/tip/prototyp/prototyp.sql#l49
*/
void processDataStream(ostream &output, istream* input) {
wregex devicePattern = wregex(L"(LABEL|UUID)=(.*)");
wregex linePattern = wregex(L"^([^\\s#]+)\\s+([^\\s]+)\\s+([^\\s]+)\\s+([^\\s]+)\\s+(\\d+)\\s+(\\d+)\\s*$");
wstring_convert < codecvt_utf8<wchar_t>> convertor; // TODO: support also other encodings.
std::shared_ptr<RelationalWriter> writer(Factory::create(output));
writer->startRelation(L"fstab",{
{L"scheme", TypeId::STRING},
{L"device", TypeId::STRING},
{L"mount_point", TypeId::STRING},
{L"type", TypeId::STRING},
// {L"types", TypeId::STRING}, // TODO: array
{L"options", TypeId::STRING}, // TODO: array
{L"dump", TypeId::INTEGER},
{L"pass", TypeId::INTEGER}
}, true);
string lineBytes;
while (getline(*input, lineBytes)) {
wstring line = convertor.from_bytes(lineBytes);
wsmatch lineMatch;
if (regex_search(line, lineMatch, linePattern) && lineMatch.size() > 0) {
int g = 1;
wstring device = lineMatch[g++];
wstring mountPoint = lineMatch[g++];
wstring type = lineMatch[g++];
wstring options = lineMatch[g++];
wstring dump = lineMatch[g++];
wstring pass = lineMatch[g++];
wsmatch deviceMatch;
if (regex_search(device, deviceMatch, devicePattern)) {
writer->writeAttribute(deviceMatch[1]);
writer->writeAttribute(deviceMatch[2]);
} else {
writer->writeAttribute(L""); // TODO: null (requires bitmap)
writer->writeAttribute(device);
}
if (mountPoint == L"none") mountPoint = L""; // TODO: null (requires bitmap)
writer->writeAttribute(mountPoint);
writer->writeAttribute(type);
writer->writeAttribute(options);
writer->writeAttribute(dump);
writer->writeAttribute(pass);
}
}
}
int main(int argc, char** argv) {
setlocale(LC_ALL, "");
CLI::untieStdIO();
//CLI cli(argc, argv);
int resultCode = CLI::EXIT_CODE_UNEXPECTED_ERROR;
try {
if (isatty(fileno(stdin))) {
/**
* Our program is executed on TTY without input stream redirection → read from default file location.
* e.g. $ relpipe-in-fstab | …
* (we don't expect that user is writing the content of fstab by hand on the terminal)
*/
ifstream s("/etc/fstab");
processDataStream(cout, &s);
} else {
/**
* Input stream comes from a file or is piped from other command → read it instead of default file.
* e.g. $ cat /etc/fstab | grep '/mnt/' | relpipe-in-fstab | …
* or $ relpipe-in-fstab < /etc/fstab | … # without UUoC
* or $ ssh example.com cat /etc/fstab | relpipe-in-fstab | …
* or $ cat | relpipe-in-fstab | … # user writes the fstab content by hand
*/
processDataStream(cout, &cin);
}
resultCode = CLI::EXIT_CODE_SUCCESS;
} catch (RelpipeWriterException e) {
fwprintf(stderr, L"Caught Writer exception: %ls\n", e.getMessge().c_str());
fwprintf(stderr, L"Debug: Input stream: eof=%ls, lastRead=%d\n", (cin.eof() ? L"true" : L"false"), cin.gcount());
resultCode = CLI::EXIT_CODE_DATA_ERROR;
}
return resultCode;
}