From 68f62489c75c8449bd6bdf8fa3c8aacbf19cc33f Mon Sep 17 00:00:00 2001
From: Maxime Devos <maximedevos@telenet.be>
Date: Thu, 11 Mar 2021 20:40:18 +0100
Subject: [PATCH 06/17] =?UTF-8?q?Define=20bindings=20to=20=E2=80=98mkdirat?=
 =?UTF-8?q?=E2=80=99=20when=20the=20C=20function=20exists.?=
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* configure.ac: Detect if ‘mkdirat’ exists.
* libguile/filesys.c (scm_mkdirat): Define the Scheme binding.
* doc/ref/posix.texi (File System): Document it.
---
 configure.ac       |  2 +-
 doc/ref/posix.texi |  6 ++++++
 libguile/filesys.c | 25 +++++++++++++++++++++++++
 libguile/filesys.h |  1 +
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 1af02bb7b..15b0ff4a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -482,7 +482,7 @@ AC_CHECK_HEADERS([assert.h crt_externs.h])
 #
 AC_CHECK_FUNCS([DINFINITY DQNAN cexp chsize clog clog10 ctermid         \
   fesetround ftime ftruncate fchown fchmod fchdir readlinkat		\
-  symlinkat getcwd geteuid getsid							\
+  symlinkat mkdirat getcwd geteuid getsid				\
   gettimeofday getuid getgid gmtime_r ioctl lstat mkdir mkdtemp mknod   \
   nice readlink rename rmdir setegid seteuid                            \
   setlocale setuid setgid setpgid setsid sigaction siginterrupt stat64  \
diff --git a/doc/ref/posix.texi b/doc/ref/posix.texi
index eff49b5a5..72e0c3032 100644
--- a/doc/ref/posix.texi
+++ b/doc/ref/posix.texi
@@ -934,6 +934,12 @@ Otherwise they are set to the value specified with @var{mode}.
 The return value is unspecified.
 @end deffn
 
+@deffn {Scheme Proecdure} mkdirat dir path [mode]
+@deffnx {C Function} scm_mkdirat (dir, path, mode)
+Like @code{mkdir}, but resolve @var{path} relative to the directory
+referred to by the file port @var{dir} instead.
+@end deffn
+
 @deffn {Scheme Procedure} rmdir path
 @deffnx {C Function} scm_rmdir (path)
 Remove the existing directory named by @var{path}.  The directory must
diff --git a/libguile/filesys.c b/libguile/filesys.c
index f86b5bb70..2d0c619af 100644
--- a/libguile/filesys.c
+++ b/libguile/filesys.c
@@ -1397,6 +1397,31 @@ SCM_DEFINE (scm_mkdir, "mkdir", 1, 1, 0,
 }
 #undef FUNC_NAME
 
+#ifdef HAVE_MKDIRAT
+SCM_DEFINE (scm_mkdirat, "mkdirat", 2, 1, 0,
+            (SCM dir, SCM path, SCM mode),
+            "Like @code{mkdir}, but resolve @var{path} relative to the directory\n"
+            "referred to by the file port @var{dir} instead.")
+#define FUNC_NAME s_scm_mkdirat
+{
+  int rv;
+  int dir_fdes;
+  mode_t c_mode;
+
+  c_mode = SCM_UNBNDP (mode) ? 0777 : scm_to_uint (mode);
+  SCM_VALIDATE_OPFPORT (SCM_ARG1, dir);
+  dir_fdes = SCM_FPORT_FDES (dir);
+
+  STRING_SYSCALL (path, c_path, rv = mkdirat (dir_fdes, c_path, c_mode));
+  if (rv != 0)
+    SCM_SYSERROR;
+
+  scm_remember_upto_here_1 (dir);
+  return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+#endif
+
 SCM_DEFINE (scm_rmdir, "rmdir", 1, 0, 0, 
             (SCM path),
 	    "Remove the existing directory named by @var{path}.  The directory must\n"
diff --git a/libguile/filesys.h b/libguile/filesys.h
index d181aca52..f0dd35ede 100644
--- a/libguile/filesys.h
+++ b/libguile/filesys.h
@@ -50,6 +50,7 @@ SCM_API SCM scm_link (SCM oldpath, SCM newpath);
 SCM_API SCM scm_rename (SCM oldname, SCM newname);
 SCM_API SCM scm_delete_file (SCM str);
 SCM_API SCM scm_mkdir (SCM path, SCM mode);
+SCM_API SCM scm_mkdirat (SCM dir, SCM path, SCM mode);
 SCM_API SCM scm_rmdir (SCM path);
 SCM_API SCM scm_directory_stream_p (SCM obj);
 SCM_API SCM scm_opendir (SCM dirname);
-- 
2.30.2