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#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;
}
}
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