#include <iostream> #include <cerrno> #include <cstdio> #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <dirent.h> #include "util.hh" string thisSystem = SYSTEM; Error::Error(const format & f) { err = f.str(); } SysError::SysError(const format & f) : Error(format("%1%: %2%") % f.str() % strerror(errno)) { } string absPath(string path, string dir) { if (path[0] != '/') { if (dir == "") { char buf[PATH_MAX]; if (!getcwd(buf, sizeof(buf))) throw SysError("cannot get cwd"); dir = buf; } path = dir + "/" + path; } return canonPath(path); } string canonPath(const string & path) { string s; if (path[0] != '/') throw Error(format("not an absolute path: `%1%'") % path); string::const_iterator i = path.begin(), end = path.end(); while (1) { /* Skip slashes. */ while (i != end && *i == '/') i++; if (i == end) break; /* Ignore `.'. */ if (*i == '.' && (i + 1 == end || i[1] == '/')) i++; /* If `..', delete the last component. */ else if (*i == '.' && i + 1 < end && i[1] == '.' && (i + 2 == end || i[2] == '/')) { if (!s.empty()) s.erase(s.rfind('/')); i += 2; } /* Normal component; copy it. */ else { s += '/'; while (i != end && *i != '/') s += *i++; } } return s.empty() ? "/" : s; } string dirOf(string path) { unsigned int pos = path.rfind('/'); if (pos == string::npos) throw Error(format("invalid file name: %1%") % path); return string(path, 0, pos); } string baseNameOf(string path) { unsigned int pos = path.rfind('/'); if (pos == string::npos) throw Error(format("invalid file name %1% ") % path); return string(path, pos + 1); } bool pathExists(const string & path) { int res; struct stat st; res = stat(path.c_str(), &st); if (!res) return true; if (errno != ENOENT) throw SysError(format("getting status of %1%") % path); return false; } void deletePath(const string & path) { msg(lvlVomit, format("deleting path `%1%'") % path); struct stat st; if (lstat(path.c_str(), &st)) throw SysError(format("getting attributes of path `%1%'") % path); if (S_ISDIR(st.st_mode)) { Strings names; DIR * dir = opendir(path.c_str()); struct dirent * dirent; while (errno = 0, dirent = readdir(dir)) { string name = dirent->d_name; if (name == "." || name == "..") continue; names.push_back(name); } closedir(dir); /* !!! close on exception */ /* Make the directory writable. */ if (!(st.st_mode & S_IWUSR)) { if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1) throw SysError(format("making `%1%' writable")); } for (Strings::iterator i = names.begin(); i != names.end(); i++) deletePath(path + "/" + *i); } if (remove(path.c_str()) == -1) throw SysError(format("cannot unlink `%1%'") % path); } void makePathReadOnly(const string & path) { struct stat st; if (lstat(path.c_str(), &st)) throw SysError(format("getting attributes of path `%1%'") % path); if (!S_ISLNK(st.st_mode) && (st.st_mode & S_IWUSR)) { if (chmod(path.c_str(), st.st_mode & ~S_IWUSR) == -1) throw SysError(format("making `%1%' read-only") % path); } if (S_ISDIR(st.st_mode)) { DIR * dir = opendir(path.c_str()); struct dirent * dirent; while (errno = 0, dirent = readdir(dir)) { string name = dirent->d_name; if (name == "." || name == "..") continue; makePathReadOnly(path + "/" + name); } closedir(dir); /* !!! close on exception */ } } static string tempName() { static int counter = 0; char * s = getenv("TMPDIR"); string tmpRoot = s ? canonPath(string(s)) : "/tmp"; return (format("%1%/nix-%2%-%3%") % tmpRoot % getpid() % counter++).str(); } string createTempDir() { while (1) { string tmpDir = tempName(); if (mkdir(tmpDir.c_str(), 0777) == 0) return tmpDir; if (errno != EEXIST) throw SysError(format("creating directory `%1%'") % tmpDir); } } Verbosity verbosity = lvlError; static int nestingLevel = 0; Nest::Nest(Verbosity level, const format & f) { if (level > verbosity) nest = false; else { msg(level, f); nest = true; nestingLevel++; } } Nest::~Nest() { if (nest) nestingLevel--; } void msg(Verbosity level, const format & f) { if (level > verbosity) return; string spaces; for (int i = 0; i < nestingLevel; i++) spaces += "| "; cerr << format("%1%%2%\n") % spaces % f.str(); } void debug(const format & f) { msg(lvlDebug, f); } void readFull(int fd, unsigned char * buf, size_t count) { while (count) { ssize_t res = read(fd, (char *) buf, count); if (res == -1) throw SysError("reading from file"); if (res == 0) throw Error("unexpected end-of-file"); count -= res; buf += res; } } void writeFull(int fd, const unsigned char * buf, size_t count) { while (count) { ssize_t res = write(fd, (char *) buf, count); if (res == -1) throw SysError("writing to file"); count -= res; buf += res; } }