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authorFlorian Weimer <fweimer@redhat.com>2020-02-18 13:02:37 +0100
committerFlorian Weimer <fweimer@redhat.com>2020-02-18 13:42:29 +0100
commitfa185f0d4529c6d70f690306f431ca23662b9138 (patch)
treead2719a1dd633d74a7a61ad59eefd08c944e19c6 /misc/fd_to_filename.c
parente4a399921390509418826e8e8995d2441f29e243 (diff)
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<fd_to_filename.h>: Add type safety and port to Hurd
The new type struct fd_to_filename makes the allocation of the backing storage explicit. Hurd uses /dev/fd, not /proc/self/fd. Co-Authored-By: Paul Eggert <eggert@cs.ucla.edu>
Diffstat (limited to 'misc/fd_to_filename.c')
-rw-r--r--misc/fd_to_filename.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/misc/fd_to_filename.c b/misc/fd_to_filename.c
new file mode 100644
index 0000000..03d1919
--- /dev/null
+++ b/misc/fd_to_filename.c
@@ -0,0 +1,38 @@
+/* Construct a pathname under /proc/self/fd (or /dev/fd for Hurd).
+ Copyright (C) 2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <fd_to_filename.h>
+
+#include <assert.h>
+#include <string.h>
+
+char *
+__fd_to_filename (int descriptor, struct fd_to_filename *storage)
+{
+ assert (descriptor >= 0);
+
+ char *p = mempcpy (storage->buffer, FD_TO_FILENAME_PREFIX,
+ strlen (FD_TO_FILENAME_PREFIX));
+
+ for (int d = descriptor; p++, (d /= 10) != 0; )
+ continue;
+ *p = '\0';
+ for (int d = descriptor; *--p = '0' + d % 10, (d /= 10) != 0; )
+ continue;
+ return storage->buffer;
+}