correct some style/performance/warnings from cppcheck

[apt.git] / apt-pkg / contrib / fileutl.cc

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 3966eb0edd41f1e175469e5f1108638020292736..1c8acd513f5dedc8df202dfb2023944e413156e9 100644 (file)
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -319,7 +319,7 @@ bool CreateDirectory(string const &Parent, string const &Path)
       return false;
 
    // we are not going to create directories "into the blue"
-   if (Path.find(Parent, 0) != 0)
+   if (Path.compare(0, Parent.length(), Parent) != 0)
       return false;
 
    vector<string> const dirs = VectorizeString(Path.substr(Parent.size()), '/');
@@ -656,9 +656,9 @@ string flNoLink(string File)
    while (1)
    {
       // Read the link
-      int Res;
+      ssize_t Res;
       if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 || 
-         (unsigned)Res >= sizeof(Buffer))
+         (size_t)Res >= sizeof(Buffer))
          return File;
       
       // Append or replace the previous path
@@ -760,12 +760,42 @@ bool WaitFd(int Fd,bool write,unsigned long timeout)
    return true;
 }
                                                                        /*}}}*/
+// MergeKeepFdsFromConfiguration - Merge APT::Keep-Fds configuration   /*{{{*/
+// ---------------------------------------------------------------------
+/* This is used to merge the APT::Keep-Fds with the provided KeepFDs
+ * set.
+ */
+void MergeKeepFdsFromConfiguration(std::set<int> &KeepFDs)
+{
+      Configuration::Item const *Opts = _config->Tree("APT::Keep-Fds");
+      if (Opts != 0 && Opts->Child != 0)
+      {
+        Opts = Opts->Child;
+        for (; Opts != 0; Opts = Opts->Next)
+        {
+           if (Opts->Value.empty() == true)
+              continue;
+           int fd = atoi(Opts->Value.c_str());
+           KeepFDs.insert(fd);
+        }
+      }
+}
+                                                                       /*}}}*/
 // ExecFork - Magical fork that sanitizes the context before execing   /*{{{*/
 // ---------------------------------------------------------------------
 /* This is used if you want to cleanse the environment for the forked 
    child, it fixes up the important signals and nukes all of the fds,
    otherwise acts like normal fork. */
 pid_t ExecFork()
+{
+      set<int> KeepFDs;
+      // we need to merge the Keep-Fds as external tools like 
+      // debconf-apt-progress use it
+      MergeKeepFdsFromConfiguration(KeepFDs);
+      return ExecFork(KeepFDs);
+}
+
+pid_t ExecFork(std::set<int> KeepFDs)
 {
    // Fork off the process
    pid_t Process = fork();
@@ -786,22 +816,8 @@ pid_t ExecFork()
       signal(SIGCONT,SIG_DFL);
       signal(SIGTSTP,SIG_DFL);
 
-      set<int> KeepFDs;
-      Configuration::Item const *Opts = _config->Tree("APT::Keep-Fds");
-      if (Opts != 0 && Opts->Child != 0)
-      {
-        Opts = Opts->Child;
-        for (; Opts != 0; Opts = Opts->Next)
-        {
-           if (Opts->Value.empty() == true)
-              continue;
-           int fd = atoi(Opts->Value.c_str());
-           KeepFDs.insert(fd);
-        }
-      }
-
       // Close all of our FDs - just in case
-      for (int K = 3; K != 40; K++)
+      for (int K = 3; K != sysconf(_SC_OPEN_MAX); K++)
       {
         if(KeepFDs.find(K) == KeepFDs.end())
            fcntl(K,F_SETFD,FD_CLOEXEC);
@@ -1244,7 +1260,7 @@ FileFd::~FileFd()
    gracefully. */
 bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual)
 {
-   int Res;
+   ssize_t Res;
    errno = 0;
    if (Actual != 0)
       *Actual = 0;
@@ -1344,7 +1360,7 @@ char* FileFd::ReadLine(char *To, unsigned long long const Size)
 /* */
 bool FileFd::Write(const void *From,unsigned long long Size)
 {
-   int Res;
+   ssize_t Res;
    errno = 0;
    do
    {
@@ -1398,7 +1414,7 @@ bool FileFd::Write(const void *From,unsigned long long Size)
 }
 bool FileFd::Write(int Fd, const void *From, unsigned long long Size)
 {
-   int Res;
+   ssize_t Res;
    errno = 0;
    do
    {
@@ -1471,14 +1487,14 @@ bool FileFd::Seek(unsigned long long To)
       d->seekpos = To;
       return true;
    }
-   int res;
+   off_t res;
 #ifdef HAVE_ZLIB
    if (d != NULL && d->gz)
       res = gzseek(d->gz,To,SEEK_SET);
    else
 #endif
       res = lseek(iFd,To,SEEK_SET);
-   if (res != (signed)To)
+   if (res != (off_t)To)
       return FileFdError("Unable to seek to %llu", To);
 
    if (d != NULL)
@@ -1509,7 +1525,7 @@ bool FileFd::Skip(unsigned long long Over)
       return true;
    }
 
-   int res;
+   off_t res;
 #ifdef HAVE_ZLIB
    if (d != NULL && d->gz != NULL)
       res = gzseek(d->gz,Over,SEEK_CUR);
@@ -1529,6 +1545,9 @@ bool FileFd::Skip(unsigned long long Over)
 /* */
 bool FileFd::Truncate(unsigned long long To)
 {
+   // truncating /dev/null is always successful - as we get an error otherwise
+   if (To == 0 && FileName == "/dev/null")
+      return true;
 #if defined HAVE_ZLIB || defined HAVE_BZ2
    if (d != NULL && (d->gz != NULL || d->bz2 != NULL))
       return FileFdError("Truncating compressed files is not implemented (%s)", FileName.c_str());
@@ -1808,3 +1827,20 @@ std::vector<std::string> Glob(std::string const &pattern, int flags)
    return result;
 }
                                                                        /*}}}*/
+
+std::string GetTempDir()
+{
+   const char *tmpdir = getenv("TMPDIR");
+
+#ifdef P_tmpdir
+   if (!tmpdir)
+      tmpdir = P_tmpdir;
+#endif
+
+   // check that tmpdir is set and exists
+   struct stat st;
+   if (!tmpdir || strlen(tmpdir) == 0 || stat(tmpdir, &st) != 0)
+      tmpdir = "/tmp";
+
+   return string(tmpdir);
+}