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Util: Add support for stdin and | piping

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In order to accomplish this, the arguments have to be stored in the
object. Because () evaluation order is not defined in the spec.

Because arguments have to be stored now, char pointers no longer work
and std::strings are stored instead. Systems object also cant be
returned as a reference anymore because you need to be able to know
which is the lhs and which is the rhs in the operator overloads.
This commit is contained in:
Riyyi
2021-09-16 18:11:47 +02:00
parent 70ccdee8c2
commit 2fca315557
2 changed files with 103 additions and 62 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/util/system.cpp
+87 -53
View File
@@ -14,70 +14,101 @@
namespace Util {
void System::operator()(const char* command)
System::System()
{
// Split modifies the string, so two copies are needed
char charCommand[strlen(command)];
strcpy(charCommand, command);
char charCommand2[strlen(command)];
strcpy(charCommand2, command);
size_t index = split(charCommand, " ");
// Preallocation is roughly ~10% faster even with just a single space.
std::vector<char*> arguments(index + 1, 0);
split(charCommand2, " ", [&arguments](int index, char* pointer) {
arguments[index] = pointer;
});
operator()(arguments);
}
void System::operator()(std::string command)
System::System(std::vector<std::string> arguments)
: m_arguments(arguments)
{
operator()(command.c_str());
}
void System::operator()(std::string_view command)
System System::operator()()
{
operator()(command.data());
return exec();
}
void System::operator()(const std::vector<const char*>& arguments)
System System::operator()(const char* command)
{
std::vector<char*> nonConstArguments(arguments.size() + 1, 0);
for (size_t i = 0; i < arguments.size(); ++i) {
nonConstArguments[i] = const_cast<char*>(arguments[i]);
}
operator()(nonConstArguments);
return operator()(std::string { command });
}
void System::operator()(const std::vector<std::string>& arguments)
System System::operator()(std::string command)
{
std::vector<char*> nonConstArguments(arguments.size() + 1, 0);
for (size_t i = 0; i < arguments.size(); ++i) {
nonConstArguments[i] = const_cast<char*>(arguments[i].c_str());
std::vector<std::string> arguments;
size_t index = 0;
while (index != std::string::npos) {
index = command.find_first_of(" ");
arguments.push_back(command.substr(0, index));
command = command.substr(index + 1);
}
operator()(nonConstArguments);
return System(arguments);
}
void System::operator()(const std::vector<std::string_view>& arguments)
System System::operator()(std::string_view command)
{
std::vector<char*> nonConstArguments(arguments.size() + 1, 0);
return operator()(std::string { command });
}
System System::operator()(const std::vector<const char*>& arguments)
{
std::vector<std::string> stringArguments(arguments.size(), "");
for (size_t i = 0; i < arguments.size(); ++i) {
nonConstArguments[i] = const_cast<char*>(arguments[i].data());
stringArguments[i] = arguments[i];
}
operator()(nonConstArguments);
return System(stringArguments);
}
System System::operator()(const std::vector<std::string>& arguments)
{
return System(arguments);
}
System System::operator()(const std::vector<std::string_view>& arguments)
{
std::vector<std::string> stringArguments(arguments.size(), "");
for (size_t i = 0; i < arguments.size(); ++i) {
stringArguments[i] = arguments[i];
}
return System(stringArguments);
}
System System::operator|(System rhs)
{
rhs.exec(exec().output());
return rhs;
}
void System::print(const std::vector<std::string>& arguments)
{
if (!arguments.size()) {
return;
}
printf("----------\n");
printf("size: %zu\n", arguments.size());
printf("command: ");
for (size_t i = 0; i < arguments.size(); ++i) {
printf("%s ", arguments.at(i).c_str());
}
printf("\n");
printf("----------\n");
}
// -----------------------------------------
void System::operator()(const std::vector<char*>& arguments)
System System::exec(std::string input)
{
int stdinFd[2];
int stdoutFd[2];
int stderrFd[2];
if (pipe(stdinFd) < 0) {
perror("\033[31;1mError\033[0m");
}
if (pipe(stdoutFd) < 0) {
perror("\033[31;1mError\033[0m");
}
@@ -93,6 +124,10 @@ void System::operator()(const std::vector<char*>& arguments)
break;
// Child
case 0: {
close(stdinFd[WriteFileDescriptor]);
dup2(stdinFd[ReadFileDescriptor], fileno(stdin));
close(stdinFd[ReadFileDescriptor]);
close(stdoutFd[ReadFileDescriptor]);
dup2(stdoutFd[WriteFileDescriptor], fileno(stdout));
close(stdoutFd[WriteFileDescriptor]);
@@ -101,7 +136,12 @@ void System::operator()(const std::vector<char*>& arguments)
dup2(stderrFd[WriteFileDescriptor], fileno(stderr));
close(stderrFd[WriteFileDescriptor]);
execvp(arguments[0], &arguments[0]);
std::vector<char*> charArguments(m_arguments.size() + 1, 0);
for (size_t i = 0; i < m_arguments.size(); ++i) {
charArguments[i] = const_cast<char*>(m_arguments[i].c_str());
}
execvp(charArguments[0], &charArguments[0]);
exit(0);
}
// Parent
@@ -109,6 +149,12 @@ void System::operator()(const std::vector<char*>& arguments)
break;
}
close(stdinFd[ReadFileDescriptor]);
if (!input.empty()) {
write(stdinFd[WriteFileDescriptor], input.c_str(), input.size());
}
close(stdinFd[WriteFileDescriptor]);
readFromFileDescriptor(stdoutFd, m_output);
readFromFileDescriptor(stderrFd, m_error);
@@ -117,11 +163,14 @@ void System::operator()(const std::vector<char*>& arguments)
result = waitpid(pid, &m_status, 0);
} while (result == -1 && errno == EINTR);
m_status = WEXITSTATUS(m_status);
return *this;
}
void System::readFromFileDescriptor(int fileDescriptor[2], std::string& output)
{
close(fileDescriptor[WriteFileDescriptor]);
output.clear();
constexpr int bufferSize = 4096;
char buffer[bufferSize];
@@ -141,19 +190,4 @@ void System::readFromFileDescriptor(int fileDescriptor[2], std::string& output)
close(fileDescriptor[ReadFileDescriptor]);
}
size_t System::split(char* split, const char* delimiters, SplitCallback callback)
{
size_t index = 0;
char* pointer = strtok(split, delimiters);
while (pointer != nullptr) {
if (callback) {
callback(index, pointer);
}
index++;
pointer = strtok(nullptr, delimiters);
}
return index;
}
} // namespace Util
src/util/system.h
+16 -9
View File
@@ -13,7 +13,8 @@ using SplitCallback = std::function<void(size_t, char*)>;
class System {
public:
System() {}
System();
System(std::vector<std::string> arguments);
virtual ~System() {}
enum FileDescriptor {
@@ -21,22 +22,28 @@ public:
WriteFileDescriptor,
};
void operator()(const char* command);
void operator()(std::string command);
void operator()(std::string_view command);
void operator()(const std::vector<const char*>& arguments);
void operator()(const std::vector<std::string>& arguments);
void operator()(const std::vector<std::string_view>& arguments);
System operator()();
System operator()(const char* command);
System operator()(std::string command);
System operator()(std::string_view command);
System operator()(const std::vector<const char*>& arguments);
System operator()(const std::vector<std::string>& arguments);
System operator()(const std::vector<std::string_view>& arguments);
System operator|(System rhs);
void print(const std::vector<std::string>& arguments);
const std::vector<std::string>& arguments() const { return m_arguments; }
std::string output() const { return m_output; }
std::string error() const { return m_error; }
int status() const { return m_status; }
private:
void operator()(const std::vector<char*>& arguments);
System exec(std::string input = "");
void readFromFileDescriptor(int fileDescriptor[2], std::string& output);
size_t split(char* split, const char* delimiters, SplitCallback callback = {});
std::vector<std::string> m_arguments;
std::string m_output;
std::string m_error;
int m_status { 0 };