Merge branch 't/rename_system_files'

[dss.git] / file.c

diff --git a/file.c b/file.c
new file mode 100644 (file)
index 0000000..6484218
--- /dev/null
+++ b/file.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2006-2010 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <assert.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "gcc-compat.h"
+#include "err.h"
+#include "str.h"
+#include "file.h"
+
+/**
+ * Call a function for each subdirectory of the current working directory.
+ *
+ * \param dirname The directory to traverse.
+ * \param func The function to call for each subdirecrtory.
+ * \param private_data Pointer to an arbitrary data structure.
+ *
+ * For each top-level directory under \a dirname, the supplied function \a func is
+ * called.  The full path of the subdirectory and the \a private_data pointer
+ * are passed to \a func.
+ *
+ * \return This function returns immediately if \a func returned a negative
+ * value. In this case \a func must set error_txt and this negative value is
+ * returned to the caller. Otherwise the function returns when all
+ * subdirectories have been passed to \a func.
+ */
+
+int for_each_subdir(int (*func)(const char *, void *), void *private_data)
+{
+       struct dirent *entry;
+       int ret;
+       DIR *dir = opendir(".");
+
+       if (!dir)
+               return -ERRNO_TO_DSS_ERROR(errno);
+       while ((entry = readdir(dir))) {
+               mode_t m;
+               struct stat s;
+
+               if (!strcmp(entry->d_name, "."))
+                       continue;
+               if (!strcmp(entry->d_name, ".."))
+                       continue;
+               ret = lstat(entry->d_name, &s) == -1;
+               if (ret == -1) {
+                       ret = -ERRNO_TO_DSS_ERROR(errno);
+                       goto out;
+               }
+               m = s.st_mode;
+               if (!S_ISDIR(m))
+                       continue;
+               ret = func(entry->d_name, private_data);
+               if (ret < 0)
+                       goto out;
+       }
+       ret = 1;
+out:
+       closedir(dir);
+       return ret;
+}
+/**
+ * Wrapper for chdir(2).
+ *
+ * \param path The specified directory.
+ *
+ * \return Standard.
+ */
+int dss_chdir(const char *path)
+{
+       if (chdir(path) >= 0)
+               return 1;
+       return -ERRNO_TO_DSS_ERROR(errno);
+}
+
+/**
+ * Set a file descriptor to non-blocking mode.
+ *
+ * \param fd The file descriptor.
+ *
+ * \return Standard.
+ */
+__must_check int mark_fd_nonblocking(int fd)
+{
+       int flags = fcntl(fd, F_GETFL);
+       if (flags < 0)
+               return -ERRNO_TO_DSS_ERROR(errno);
+       flags = fcntl(fd, F_SETFL, ((long)flags) | O_NONBLOCK);
+       if (flags < 0)
+               return -ERRNO_TO_DSS_ERROR(errno);
+       return 1;
+}
+
+/**
+ * dss' wrapper for select(2).
+ *
+ * It calls select(2) (with no exceptfds) and starts over if select() was
+ * interrupted by a signal.
+ *
+ * \param n The highest-numbered descriptor in any of the two sets, plus 1.
+ * \param readfds fds that should be checked for readability.
+ * \param writefds fds that should be checked for writablility.
+ * \param timeout_tv upper bound on the amount of time elapsed before select()
+ * returns.
+ *
+ * \return The return value of the underlying select() call on success, the
+ * negative system error code on errors.
+ *
+ * All arguments are passed verbatim to select(2).
+ * \sa select(2) select_tut(2).
+ */
+int dss_select(int n, fd_set *readfds, fd_set *writefds,
+               struct timeval *timeout_tv)
+{
+       int ret, err;
+       do {
+               ret = select(n, readfds, writefds, NULL, timeout_tv);
+               err = errno;
+       } while (ret < 0 && err == EINTR);
+       if (ret < 0)
+               return -ERRNO_TO_DSS_ERROR(errno);
+       return ret;
+}