#pragma once
#include "types.hh"
#include "logging.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <signal.h>
#include <functional>
#include <limits>
#include <cstdio>
#include <map>
#include <sstream>
#include <experimental/optional>
#ifndef HAVE_STRUCT_DIRENT_D_TYPE
#define DT_UNKNOWN 0
#define DT_REG 1
#define DT_LNK 2
#define DT_DIR 3
#endif
namespace nix {
/* Return an environment variable. */
string getEnv(const string & key, const string & def = "");
/* Get the entire environment. */
std::map<std::string, std::string> getEnv();
/* Return an absolutized path, resolving paths relative to the
specified directory, or the current directory otherwise. The path
is also canonicalised. */
Path absPath(Path path, Path dir = "");
/* Canonicalise a path by removing all `.' or `..' components and
double or trailing slashes. Optionally resolves all symlink
components such that each component of the resulting path is *not*
a symbolic link. */
Path canonPath(const Path & path, bool resolveSymlinks = false);
/* Return the directory part of the given canonical path, i.e.,
everything before the final `/'. If the path is the root or an
immediate child thereof (e.g., `/foo'), this means an empty string
is returned. */
Path dirOf(const Path & path);
/* Return the base name of the given canonical path, i.e., everything
following the final `/'. */
string baseNameOf(const Path & path);
/* Check whether a given path is a descendant of the given
directory. */
bool isInDir(const Path & path, const Path & dir);
/* Get status of `path'. */
struct stat lstat(const Path & path);
/* Return true iff the given path exists. */
bool pathExists(const Path & path);
/* Read the contents (target) of a symbolic link. The result is not
in any way canonicalised. */
Path readLink(const Path & path);
bool isLink(const Path & path);
/* Read the contents of a directory. The entries `.' and `..' are
removed. */
struct DirEntry
{
string name;
ino_t ino;
unsigned char type; // one of DT_*
DirEntry(const string & name, ino_t ino, unsigned char type)
: name(name), ino(ino), type(type) { }
};
typedef vector<DirEntry> DirEntries;
DirEntries readDirectory(const Path & path);
unsigned char getFileType(const Path & path);
/* Read the contents of a file into a string. */
string readFile(int fd);
string readFile(const Path & path, bool drain = false);
/* Write a string to a file. */
void writeFile(const Path & path, const string & s, mode_t mode = 0666);
/* Read a line from a file descriptor. */
string readLine(int fd);
/* Write a line to a file descriptor. */
void writeLine(int fd, string s);
/* Delete a path; i.e., in the case of a directory, it is deleted
recursively. It's not an error if the path does not exist. The
second variant returns the number of bytes and blocks freed. */
void deletePath(const Path & path);
void deletePath(const Path & path, unsigned long long & bytesFreed);
/* Create a temporary directory. */
Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
/* Return $HOME or the user's home directory from /etc/passwd. */
Path getHome();
/* Return $XDG_CACHE_HOME or $HOME/.cache. */
Path getCacheDir();
/* Return $XDG_CONFIG_HOME or $HOME/.config. */
Path getConfigDir();
/* Return $XDG_DATA_HOME or $HOME/.local/share. */
Path getDataDir();
/* Create a directory and all its parents, if necessary. Returns the
list of created directories, in order of creation. */
Paths createDirs(const Path & path);
/* Create a symlink. */
void createSymlink(const Path & target, const Path & link);
/* Atomically create or replace a symlink. */
void replaceSymlink(const Path & target, const Path & link);
/* Wrappers arount read()/write() that read/write exactly the
requested number of bytes. */
void readFull(int fd, unsigned char * buf, size_t count);
void writeFull(int fd, const unsigned char * buf, size_t count, bool allowInterrupts = true);
void writeFull(int fd, const string & s, bool allowInterrupts = true);
MakeError(EndOfFile, Error)
/* Read a file descriptor until EOF occurs. */
string drainFD(int fd);
/* Automatic cleanup of resources. */
class AutoDelete
{
Path path;
bool del;
bool recursive;
public:
AutoDelete();
AutoDelete(const Path & p, bool recursive = true);
~AutoDelete();
void cancel();
void reset(const Path & p, bool recursive = true);
operator Path() const { return path; }
};
class AutoCloseFD
{
int fd;
void close();
public:
AutoCloseFD();
AutoCloseFD(int fd);
AutoCloseFD(const AutoCloseFD & fd) = delete;
AutoCloseFD(AutoCloseFD&& fd);
~AutoCloseFD();
AutoCloseFD& operator =(const AutoCloseFD & fd) = delete;
AutoCloseFD& operator =(AutoCloseFD&& fd);
int get() const;
explicit operator bool() const;
int release();
};
class Pipe
{
public:
AutoCloseFD readSide, writeSide;
void create();
};
struct DIRDeleter
{
void operator()(DIR * dir) const {
closedir(dir);
}
};
typedef std::unique_ptr<DIR, DIRDeleter> AutoCloseDir;
class Pid
{
pid_t pid = -1;
bool separatePG = false;
int killSignal = SIGKILL;
public:
Pid();
Pid(pid_t pid);
~Pid();
void operator =(pid_t pid);
operator pid_t();
int kill();
int wait();
void setSeparatePG(bool separatePG);
void setKillSignal(int signal);
pid_t release();
};
/* Kill all processes running under the specified uid by sending them
a SIGKILL. */
void killUser(uid_t uid);
/* Fork a process that runs the given function, and return the child
pid to the caller. */
struct ProcessOptions
{
string errorPrefix = "error: ";
bool dieWithParent = true;
bool runExitHandlers = false;
bool allowVfork = true;
};
pid_t startProcess(std::function<void()> fun, const ProcessOptions & options = ProcessOptions());
/* Run a program and return its stdout in a string (i.e., like the
shell backtick operator). */
string runProgram(Path program, bool searchPath = false,
const Strings & args = Strings(),
const std::experimental::optional<std::string> & input = {});
class ExecError : public Error
{
public:
int status;
template<typename... Args>
ExecError(int status, Args... args)
: Error(args...), status(status)
{ }
};
/* Convert a list of strings to a null-terminated vector of char
*'s. The result must not be accessed beyond the lifetime of the
list of strings. */
std::vector<char *> stringsToCharPtrs(const Strings & ss);
/* Close all file descriptors except those listed in the given set.
Good practice in child processes. */
void closeMostFDs(const set<int> & exceptions);
/* Set the close-on-exec flag for the given file descriptor. */
void closeOnExec(int fd);
/* User interruption. */
extern bool _isInterrupted;
void setInterruptThrown();
void _interrupted();
void inline checkInterrupt()
{
if (_isInterrupted) _interrupted();
}
MakeError(Interrupted, BaseError)
MakeError(FormatError, Error)
/* String tokenizer. */
template<class C> C tokenizeString(const string & s, const string & separators = " \t\n\r");
/* Concatenate the given strings with a separator between the
elements. */
string concatStringsSep(const string & sep, const Strings & ss);
string concatStringsSep(const string & sep, const StringSet & ss);
/* Remove trailing whitespace from a string. */
string chomp(const string & s);
/* Remove whitespace from the start and end of a string. */
string trim(const string & s, const string & whitespace = " \n\r\t");
/* Replace all occurrences of a string inside another string. */
string replaceStrings(const std::string & s,
const std::string & from, const std::string & to);
/* Convert the exit status of a child as returned by wait() into an
error string. */
string statusToString(int status);
bool statusOk(int status);
/* Parse a string into an integer. */
template<class N> bool string2Int(const string & s, N & n)
{
if (string(s, 0, 1) == "-" && !std::numeric_limits<N>::is_signed)
return false;
std::istringstream str(s);
str >> n;
return str && str.get() == EOF;
}
/* Parse a string into a float. */
template<class N> bool string2Float(const string & s, N & n)
{
std::istringstream str(s);
str >> n;
return str && str.get() == EOF;
}
/* Return true iff `s' starts with `prefix'. */
bool hasPrefix(const string & s, const string & prefix);
/* Return true iff `s' ends in `suffix'. */
bool hasSuffix(const string & s, const string & suffix);
/* Convert a string to lower case. */
std::string toLower(const std::string & s);
/* Escape a string that contains octal-encoded escape codes such as
used in /etc/fstab and /proc/mounts (e.g. "foo\040bar" decodes to
"foo bar"). */
string decodeOctalEscaped(const string & s);
/* Exception handling in destructors: print an error message, then
ignore the exception. */
void ignoreException();
/* Some ANSI escape sequences. */
#define ANSI_NORMAL "\e[0m"
#define ANSI_BOLD "\e[1m"
#define ANSI_RED "\e[31;1m"
#define ANSI_GREEN "\e[32;1m"
#define ANSI_BLUE "\e[34;1m"
/* Filter out ANSI escape codes from the given string. If ‘nixOnly’ is
set, only filter escape codes generated by Nixpkgs' stdenv (used to
denote nesting etc.). */
string filterANSIEscapes(const string & s, bool nixOnly = false);
/* Base64 encoding/decoding. */
string base64Encode(const string & s);
string base64Decode(const string & s);
/* Get a value for the specified key from an associate container, or a
default value if the key doesn't exist. */
template <class T>
string get(const T & map, const string & key, const string & def = "")
{
auto i = map.find(key);
return i == map.end() ? def : i->second;
}
/* Call ‘failure’ with the current exception as argument. If ‘failure’
throws an exception, abort the program. */
void callFailure(const std::function<void(std::exception_ptr exc)> & failure,
std::exception_ptr exc = std::current_exception());
/* Evaluate the function ‘f’. If it returns a value, call ‘success’
with that value as its argument. If it or ‘success’ throws an
exception, call ‘failure’. If ‘failure’ throws an exception, abort
the program. */
template<class T>
void sync2async(
const std::function<void(T)> & success,
const std::function<void(std::exception_ptr exc)> & failure,
const std::function<T()> & f)
{
try {
success(f());
} catch (...) {
callFailure(failure);
}
}
/* Call the function ‘success’. If it throws an exception, call
‘failure’. If that throws an exception, abort the program. */
template<class T>
void callSuccess(
const std::function<void(T)> & success,
const std::function<void(std::exception_ptr exc)> & failure,
T && arg)
{
try {
success(arg);
} catch (...) {
callFailure(failure);
}
}
/* Start a thread that handles various signals. Also block those signals
on the current thread (and thus any threads created by it). */
void startSignalHandlerThread();
/* Restore default signal handling. */
void restoreSignals();
struct InterruptCallback
{
virtual ~InterruptCallback() { };
};
/* Register a function that gets called on SIGINT (in a non-signal
context). */
std::unique_ptr<InterruptCallback> createInterruptCallback(
std::function<void()> callback);
void triggerInterrupt();
/* A RAII class that causes the current thread to receive SIGUSR1 when
the signal handler thread receives SIGINT. That is, this allows
SIGINT to be multiplexed to multiple threads. */
struct ReceiveInterrupts
{
pthread_t target;
std::unique_ptr<InterruptCallback> callback;
ReceiveInterrupts()
: target(pthread_self())
, callback(createInterruptCallback([&]() { pthread_kill(target, SIGUSR1); }))
{ }
};
/* A RAII helper that increments a counter on construction and
decrements it on destruction. */
template<typename T>
struct MaintainCount
{
T & counter;
long delta;
MaintainCount(T & counter, long delta = 1) : counter(counter), delta(delta) { counter += delta; }
~MaintainCount() { counter -= delta; }
};
}
