eldritch horrors
4162a66cee
this much more closely mimics what is actually happening: we're reading
data from somewhere else, actively, rather than passively waiting. with
the data flow matching the underlying system interactions better we can
remove a few sinkToSource calls that merely exists to undo the mismatch
caused by not treating subprocess output as a data source to begin with
Change-Id: If4abfc2f8398fb5e88c9b91a8bdefd5504bb2d11
136 lines
2.8 KiB
C++
136 lines
2.8 KiB
C++
#pragma once
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///@file
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#include "types.hh"
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#include "error.hh"
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#include "file-descriptor.hh"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <dirent.h>
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#include <unistd.h>
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#include <signal.h>
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#include <functional>
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#include <map>
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#include <optional>
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namespace nix {
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struct Sink;
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struct Source;
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class Pid
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{
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pid_t pid = -1;
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bool separatePG = false;
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int killSignal = SIGKILL;
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public:
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Pid();
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explicit Pid(pid_t pid): pid(pid) {}
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Pid(Pid && other);
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Pid & operator=(Pid && other);
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~Pid() noexcept(false);
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explicit operator bool() const { return pid != -1; }
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int kill();
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int wait();
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void setSeparatePG(bool separatePG);
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void setKillSignal(int signal);
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pid_t release();
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pid_t get() const { return pid; }
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};
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/**
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* Kill all processes running under the specified uid by sending them
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* a SIGKILL.
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*/
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void killUser(uid_t uid);
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/**
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* Fork a process that runs the given function, and return the child
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* pid to the caller.
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*/
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struct ProcessOptions
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{
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std::string errorPrefix = "";
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bool dieWithParent = true;
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bool runExitHandlers = false;
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/**
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* use clone() with the specified flags (Linux only)
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*/
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int cloneFlags = 0;
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};
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[[nodiscard]]
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Pid startProcess(std::function<void()> fun, const ProcessOptions & options = ProcessOptions());
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/**
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* Run a program and return its stdout in a string (i.e., like the
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* shell backtick operator).
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*/
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std::string runProgram(Path program, bool searchPath = false,
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const Strings & args = Strings(), bool isInteractive = false);
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struct RunOptions
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{
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Path program;
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bool searchPath = true;
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Strings args;
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std::optional<uid_t> uid;
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std::optional<uid_t> gid;
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std::optional<Path> chdir;
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std::optional<std::map<std::string, std::string>> environment;
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bool captureStdout = false;
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bool mergeStderrToStdout = false;
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bool isInteractive = false;
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};
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struct [[nodiscard("you must call RunningProgram::wait()")]] RunningProgram
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{
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friend RunningProgram runProgram2(const RunOptions & options);
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private:
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Path program;
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Pid pid;
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std::unique_ptr<Source> stdoutSource;
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AutoCloseFD stdout_;
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RunningProgram(PathView program, Pid pid, AutoCloseFD stdout);
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public:
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RunningProgram() = default;
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~RunningProgram();
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void wait();
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Source * stdout() const { return stdoutSource.get(); }
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};
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std::pair<int, std::string> runProgram(RunOptions && options);
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RunningProgram runProgram2(const RunOptions & options);
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class ExecError : public Error
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{
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public:
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int status;
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template<typename... Args>
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ExecError(int status, const Args & ... args)
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: Error(args...), status(status)
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{ }
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};
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/**
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* Convert the exit status of a child as returned by wait() into an
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* error string.
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*/
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std::string statusToString(int status);
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bool statusOk(int status);
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}
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