Mirror of GNU Guix
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#pragma once
#include "types.hh"
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <unistd.h>
#include <signal.h>
#include <functional>
#include <cstdio>
namespace nix {
#define foreach(it_type, it, collection) \
for (it_type it = (collection).begin(); it != (collection).end(); ++it)
#define foreach_reverse(it_type, it, collection) \
for (it_type it = (collection).rbegin(); it != (collection).rend(); ++it)
/* Return an environment variable. */
string getEnv(const string & key, const string & def = "");
/* 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);
/* 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. Don't use this at home, kids. 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);
/* 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);
template<class T, class A>
T singleton(const A & a)
T t;
return t;
/* Messages. */
typedef enum {
ltPretty, /* nice, nested output */
ltEscapes, /* nesting indicated using escape codes (for log2xml) */
ltFlat /* no nesting */
} LogType;
extern LogType logType;
extern Verbosity verbosity; /* suppress msgs > this */
class Nest
bool nest;
void open(Verbosity level, const FormatOrString & fs);
void close();
void printMsg_(Verbosity level, const FormatOrString & fs);
#define startNest(varName, level, f) \
Nest varName; \
if (level <= verbosity) { \
varName.open(level, (f)); \
#define printMsg(level, f) \
do { \
if (level <= nix::verbosity) { \
nix::printMsg_(level, (f)); \
} \
} while (0)
#define debug(f) printMsg(lvlDebug, f)
void warnOnce(bool & haveWarned, const FormatOrString & fs);
void writeToStderr(const string & s);
extern void (*_writeToStderr) (const unsigned char * buf, size_t count);
/* 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);
void writeFull(int fd, const string & s);
MakeError(EndOfFile, Error)
/* Read a file descriptor until EOF occurs. */
string drainFD(int fd);
/* Automatic cleanup of resources. */
template <class T>
struct AutoDeleteArray
T * p;
AutoDeleteArray(T * p) : p(p) { }
delete [] p;
class AutoDelete
Path path;
bool del;
bool recursive;
AutoDelete(const Path & p, bool recursive = true);
void cancel();
class AutoCloseFD
int fd;
AutoCloseFD(int fd);
AutoCloseFD(const AutoCloseFD & fd);
void operator =(int fd);
operator int() const;
void close();
bool isOpen();
int borrow();
class Pipe
AutoCloseFD readSide, writeSide;
void create();
class AutoCloseDir
DIR * dir;
AutoCloseDir(DIR * dir);
void operator =(DIR * dir);
operator DIR *();
void close();
class Pid
pid_t pid;
bool separatePG;
int killSignal;
Pid(pid_t pid);
void operator =(pid_t pid);
operator pid_t();
void kill(bool quiet = false);
int wait(bool block);
void setSeparatePG(bool separatePG);
void setKillSignal(int signal);
/* Kill all processes running under the specified uid by sending them
void killUser(uid_t uid);
/* Fork a process that runs the given function, and return the child
pid to the caller. */
pid_t startProcess(std::function<void()> fun, bool dieWithParent = true,
const string & errorPrefix = "error: ", bool runExitHandlers = false);
/* 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());
MakeError(ExecError, Error)
/* 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 stdin, stdout, stderr, and 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 volatile sig_atomic_t _isInterrupted;
void _interrupted();
void inline checkInterrupt()
if (_isInterrupted) _interrupted();
MakeError(Interrupted, BaseError)
/* 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);
/* 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)
std::istringstream str(s);
str >> n;
return str && str.get() == EOF;
/* Return true iff `s' ends in `suffix'. */
bool hasSuffix(const string & s, const string & suffix);
/* Read string `s' from stream `str'. */
void expect(std::istream & str, const string & s);
MakeError(FormatError, Error)
/* Read a C-style string from stream `str'. */
string parseString(std::istream & str);
/* Utility function used to parse legacy ATerms. */
bool endOfList(std::istream & str);
/* Exception handling in destructors: print an error message, then
ignore the exception. */
void ignoreException();