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-rw-r--r--include/closestream.h114
1 files changed, 114 insertions, 0 deletions
diff --git a/include/closestream.h b/include/closestream.h
new file mode 100644
index 0000000..711ca5b
--- /dev/null
+++ b/include/closestream.h
@@ -0,0 +1,114 @@
+/*
+ * No copyright is claimed. This code is in the public domain; do with
+ * it what you wish.
+ */
+#ifndef UTIL_LINUX_CLOSESTREAM_H
+#define UTIL_LINUX_CLOSESTREAM_H
+
+#include <stdio.h>
+#ifdef HAVE_STDIO_EXT_H
+#include <stdio_ext.h>
+#endif
+#include <unistd.h>
+
+#include "c.h"
+#include "nls.h"
+
+#ifndef CLOSE_EXIT_CODE
+# define CLOSE_EXIT_CODE EXIT_FAILURE
+#endif
+
+static inline int
+close_stream(FILE * stream)
+{
+#ifdef HAVE___FPENDING
+ const int some_pending = (__fpending(stream) != 0);
+#endif
+ const int prev_fail = (ferror(stream) != 0);
+ const int fclose_fail = (fclose(stream) != 0);
+
+ if (prev_fail || (fclose_fail && (
+#ifdef HAVE___FPENDING
+ some_pending ||
+#endif
+ errno != EBADF))) {
+ if (!fclose_fail && !(errno == EPIPE))
+ errno = 0;
+ return EOF;
+ }
+ return 0;
+}
+
+static inline int
+flush_standard_stream(FILE *stream)
+{
+ int fd;
+
+ errno = 0;
+
+ if (ferror(stream) != 0 || fflush(stream) != 0)
+ goto error;
+
+ /*
+ * Calling fflush is not sufficient on some filesystems
+ * like e.g. NFS, which may defer the actual flush until
+ * close. Calling fsync would help solve this, but would
+ * probably result in a performance hit. Thus, we work
+ * around this issue by calling close on a dup'd file
+ * descriptor from the stream.
+ */
+ if ((fd = fileno(stream)) < 0 || (fd = dup(fd)) < 0 || close(fd) != 0)
+ goto error;
+
+ return 0;
+error:
+ return (errno == EBADF) ? 0 : EOF;
+}
+
+/* Meant to be used atexit(close_stdout); */
+static inline void
+close_stdout(void)
+{
+ if (flush_standard_stream(stdout) != 0 && !(errno == EPIPE)) {
+ if (errno)
+ warn(_("write error"));
+ else
+ warnx(_("write error"));
+ _exit(CLOSE_EXIT_CODE);
+ }
+
+ if (flush_standard_stream(stderr) != 0)
+ _exit(CLOSE_EXIT_CODE);
+}
+
+static inline void
+close_stdout_atexit(void)
+{
+ /*
+ * Note that close stdout at exit disables ASAN to report memory leaks
+ */
+#if !HAS_FEATURE_ADDRESS_SANITIZER
+ atexit(close_stdout);
+#endif
+}
+
+#ifndef HAVE_FSYNC
+static inline int
+fsync(int fd __attribute__((__unused__)))
+{
+ return 0;
+}
+#endif
+
+static inline int
+close_fd(int fd)
+{
+ const int fsync_fail = (fsync(fd) != 0);
+ const int close_fail = (close(fd) != 0);
+
+ if (fsync_fail || close_fail)
+ return EOF;
+ return 0;
+}
+
+#endif /* UTIL_LINUX_CLOSESTREAM_H */