#pragma once #include "types.hh" #include <sys/types.h> #include <sys/stat.h> #include <dirent.h> #include <unistd.h> #include <signal.h> #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. */ Strings readDirectory(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; t.insert(a); 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 { private: bool nest; public: Nest(); ~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 <= verbosity) { \ 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); 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) { } ~AutoDeleteArray() { delete [] p; } }; class AutoDelete { Path path; bool del; bool recursive; public: AutoDelete(const Path & p, bool recursive = true); ~AutoDelete(); void cancel(); }; class AutoCloseFD { int fd; public: AutoCloseFD(); AutoCloseFD(int fd); AutoCloseFD(const AutoCloseFD & fd); ~AutoCloseFD(); void operator =(int fd); operator int() const; void close(); bool isOpen(); int borrow(); }; class Pipe { public: AutoCloseFD readSide, writeSide; void create(); }; class AutoCloseDir { DIR * dir; public: AutoCloseDir(); AutoCloseDir(DIR * dir); ~AutoCloseDir(); void operator =(DIR * dir); operator DIR *(); void close(); }; class Pid { pid_t pid; bool separatePG; int killSignal; public: Pid(); ~Pid(); void operator =(pid_t pid); operator pid_t(); void kill(); int wait(bool block); void setSeparatePG(bool separatePG); void setKillSignal(int signal); }; /* Kill all processes running under the specified uid by sending them a SIGKILL. */ void killUser(uid_t uid); /* 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()); /* 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); /* Call vfork() if available, otherwise fork(). */ extern pid_t (*maybeVfork)(); /* 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; } template<class N> string int2String(N n) { std::ostringstream str; str << n; return str.str(); } /* 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); /* 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); /* 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(); }