370 lines
		
	
	
	
		
			8.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			370 lines
		
	
	
	
		
			8.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
#pragma once
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#include "types.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 <cstdio>
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namespace nix {
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#define foreach(it_type, it, collection)                                \
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    for (it_type it = (collection).begin(); it != (collection).end(); ++it)
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#define foreach_reverse(it_type, it, collection)                                \
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    for (it_type it = (collection).rbegin(); it != (collection).rend(); ++it)
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/* Return an environment variable. */
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string getEnv(const string & key, const string & def = "");
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/* Return an absolutized path, resolving paths relative to the
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   specified directory, or the current directory otherwise.  The path
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   is also canonicalised. */
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Path absPath(Path path, Path dir = "");
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/* Canonicalise a path by removing all `.' or `..' components and
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   double or trailing slashes.  Optionally resolves all symlink
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   components such that each component of the resulting path is *not*
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   a symbolic link. */
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Path canonPath(const Path & path, bool resolveSymlinks = false);
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/* Return the directory part of the given canonical path, i.e.,
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   everything before the final `/'.  If the path is the root or an
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   immediate child thereof (e.g., `/foo'), this means an empty string
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   is returned. */
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Path dirOf(const Path & path);
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/* Return the base name of the given canonical path, i.e., everything
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   following the final `/'. */
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string baseNameOf(const Path & path);
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/* Check whether a given path is a descendant of the given
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   directory. */
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bool isInDir(const Path & path, const Path & dir);
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/* Get status of `path'. */
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struct stat lstat(const Path & path);
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/* Return true iff the given path exists. */
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bool pathExists(const Path & path);
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/* Read the contents (target) of a symbolic link.  The result is not
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   in any way canonicalised. */
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Path readLink(const Path & path);
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bool isLink(const Path & path);
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/* Read the contents of a directory.  The entries `.' and `..' are
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   removed. */
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struct DirEntry
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{
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    string name;
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    ino_t ino;
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    unsigned char type; // one of DT_*
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    DirEntry(const string & name, ino_t ino, unsigned char type)
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        : name(name), ino(ino), type(type) { }
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};
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typedef vector<DirEntry> DirEntries;
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DirEntries readDirectory(const Path & path);
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unsigned char getFileType(const Path & path);
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/* Read the contents of a file into a string. */
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string readFile(int fd);
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string readFile(const Path & path, bool drain = false);
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/* Write a string to a file. */
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void writeFile(const Path & path, const string & s);
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/* Read a line from a file descriptor. */
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string readLine(int fd);
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/* Write a line to a file descriptor. */
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void writeLine(int fd, string s);
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/* Delete a path; i.e., in the case of a directory, it is deleted
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   recursively.  Don't use this at home, kids.  The second variant
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   returns the number of bytes and blocks freed. */
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void deletePath(const Path & path);
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void deletePath(const Path & path, unsigned long long & bytesFreed);
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/* Create a temporary directory. */
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Path createTempDir(const Path & tmpRoot = "", const Path & prefix = "nix",
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    bool includePid = true, bool useGlobalCounter = true, mode_t mode = 0755);
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/* Create a directory and all its parents, if necessary.  Returns the
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   list of created directories, in order of creation. */
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Paths createDirs(const Path & path);
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/* Create a symlink. */
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void createSymlink(const Path & target, const Path & link);
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template<class T, class A>
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T singleton(const A & a)
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{
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    T t;
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    t.insert(a);
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    return t;
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}
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/* Messages. */
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typedef enum {
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    ltPretty,   /* nice, nested output */
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    ltEscapes,  /* nesting indicated using escape codes (for log2xml) */
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    ltFlat      /* no nesting */
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} LogType;
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extern LogType logType;
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extern Verbosity verbosity; /* suppress msgs > this */
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class Nest
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{
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private:
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    bool nest;
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public:
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    Nest();
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    ~Nest();
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    void open(Verbosity level, const FormatOrString & fs);
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    void close();
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};
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void printMsg_(Verbosity level, const FormatOrString & fs);
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#define startNest(varName, level, f) \
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    Nest varName; \
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    if (level <= verbosity) { \
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      varName.open(level, (f)); \
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    }
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#define printMsg(level, f) \
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    do { \
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        if (level <= nix::verbosity) { \
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            nix::printMsg_(level, (f)); \
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        } \
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    } while (0)
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#define debug(f) printMsg(lvlDebug, f)
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void warnOnce(bool & haveWarned, const FormatOrString & fs);
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void writeToStderr(const string & s);
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extern void (*_writeToStderr) (const unsigned char * buf, size_t count);
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/* Wrappers arount read()/write() that read/write exactly the
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   requested number of bytes. */
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void readFull(int fd, unsigned char * buf, size_t count);
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void writeFull(int fd, const unsigned char * buf, size_t count);
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void writeFull(int fd, const string & s);
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MakeError(EndOfFile, Error)
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/* Read a file descriptor until EOF occurs. */
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string drainFD(int fd);
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/* Automatic cleanup of resources. */
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template <class T>
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struct AutoDeleteArray
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{
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    T * p;
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    AutoDeleteArray(T * p) : p(p) { }
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    ~AutoDeleteArray()
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    {
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        delete [] p;
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    }
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};
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class AutoDelete
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{
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    Path path;
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    bool del;
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    bool recursive;
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public:
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    AutoDelete(const Path & p, bool recursive = true);
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    ~AutoDelete();
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    void cancel();
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};
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class AutoCloseFD
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{
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    int fd;
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public:
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    AutoCloseFD();
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    AutoCloseFD(int fd);
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    AutoCloseFD(const AutoCloseFD & fd);
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    ~AutoCloseFD();
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    void operator =(int fd);
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    operator int() const;
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    void close();
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    bool isOpen();
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    int borrow();
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};
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class Pipe
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{
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public:
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    AutoCloseFD readSide, writeSide;
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    void create();
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};
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class AutoCloseDir
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{
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    DIR * dir;
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public:
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    AutoCloseDir();
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    AutoCloseDir(DIR * dir);
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    ~AutoCloseDir();
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    void operator =(DIR * dir);
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    operator DIR *();
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    void close();
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};
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class Pid
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{
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    pid_t pid;
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    bool separatePG;
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    int killSignal;
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public:
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    Pid();
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    Pid(pid_t pid);
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    ~Pid();
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    void operator =(pid_t pid);
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    operator pid_t();
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    void kill(bool quiet = false);
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    int wait(bool block);
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    void setSeparatePG(bool separatePG);
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    void setKillSignal(int signal);
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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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void killUser(uid_t uid);
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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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pid_t startProcess(std::function<void()> fun, bool dieWithParent = true,
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    const string & errorPrefix = "error: ", bool runExitHandlers = false);
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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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string runProgram(Path program, bool searchPath = false,
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    const Strings & args = Strings());
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MakeError(ExecError, Error)
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/* Convert a list of strings to a null-terminated vector of char
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   *'s. The result must not be accessed beyond the lifetime of the
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   list of strings. */
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std::vector<char *> stringsToCharPtrs(const Strings & ss);
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/* Close all file descriptors except stdin, stdout, stderr, and those
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   listed in the given set.  Good practice in child processes. */
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void closeMostFDs(const set<int> & exceptions);
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/* Set the close-on-exec flag for the given file descriptor. */
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void closeOnExec(int fd);
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/* User interruption. */
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extern volatile sig_atomic_t _isInterrupted;
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void _interrupted();
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void inline checkInterrupt()
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{
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    if (_isInterrupted) _interrupted();
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}
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MakeError(Interrupted, BaseError)
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/* String tokenizer. */
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template<class C> C tokenizeString(const string & s, const string & separators = " \t\n\r");
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/* Concatenate the given strings with a separator between the
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   elements. */
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string concatStringsSep(const string & sep, const Strings & ss);
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string concatStringsSep(const string & sep, const StringSet & ss);
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/* Remove trailing whitespace from a string. */
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string chomp(const string & s);
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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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string statusToString(int status);
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bool statusOk(int status);
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/* Parse a string into an integer. */
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template<class N> bool string2Int(const string & s, N & n)
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{
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    std::istringstream str(s);
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    str >> n;
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    return str && str.get() == EOF;
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}
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/* Return true iff `s' ends in `suffix'. */
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bool hasSuffix(const string & s, const string & suffix);
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/* Read string `s' from stream `str'. */
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void expect(std::istream & str, const string & s);
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MakeError(FormatError, Error)
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/* Read a C-style string from stream `str'. */
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string parseString(std::istream & str);
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/* Utility function used to parse legacy ATerms. */
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bool endOfList(std::istream & str);
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/* Escape a string that contains octal-encoded escape codes such as
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   used in /etc/fstab and /proc/mounts (e.g. "foo\040bar" decodes to
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   "foo bar"). */
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string decodeOctalEscaped(const string & s);
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/* Exception handling in destructors: print an error message, then
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   ignore the exception. */
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void ignoreException();
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}
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