Guix-Upstream: https://lists.gnu.org/archive/html/guile-devel/2021-11/msg00005.html
From: Maxime Devos
Subject: [PATCH v2 04/14] =?UTF-8?q?Define=20=E2=80=98symlinkat=E2=80=99?=
=?UTF-8?q?=20wrapper=20when=20supported.?=
Date: Tue, 16 Nov 2021 11:06:27 +0000
Message-Id: <20211116110637.125579-5-maximedevos@telenet.be>
In-Reply-To: <20211116110637.125579-1-maximedevos@telenet.be>
References: <175c3a6572e832d84927937b309a3095cadf5702.camel@telenet.be>
<20211116110637.125579-1-maximedevos@telenet.be>
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* configure.ac: Detect whether ‘symlinkat’ exists.
* libguile/filesys.c (scm_symlinkat): Define a Scheme binding
when it exists.
* libguile/filesys.h: Make the binding part of the public C API.
* doc/ref/posix.texi (File System): Document the binding.
* test-suite/tests/filesys.test ("symlinkat"): Test it.
---
configure.ac | 2 +-
doc/ref/posix.texi | 6 ++++++
libguile/filesys.c | 23 +++++++++++++++++++++++
libguile/filesys.h | 1 +
test-suite/tests/filesys.test | 27 +++++++++++++++++++++++++++
5 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/configure.ac b/configure.ac
index ddf330d96..b2e9ef3e9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -485,7 +485,7 @@ 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 \
- getcwd geteuid getsid \
+ symlinkat 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 b6deffd43..a329eec39 100644
--- a/doc/ref/posix.texi
+++ b/doc/ref/posix.texi
@@ -891,6 +891,12 @@ Create a symbolic link named @var{newpath} with the value (i.e., pointing to)
@var{oldpath}. The return value is unspecified.
@end deffn
+@deffn {Scheme Procedure} symlinkat dir oldpath newpath
+@deffnx {C Function} scm_symlinkat (dir, oldpath, newpath)
+Like @code{symlink}, but resolve @var{newpath} relative to
+the directory referred to by the file port @var{dir}.
+@end deffn
+
@deffn {Scheme Procedure} mkdir path [mode]
@deffnx {C Function} scm_mkdir (path, mode)
Create a new directory named by @var{path}. If @var{mode} is omitted
diff --git a/libguile/filesys.c b/libguile/filesys.c
index c5bedec07..bfd223434 100644
--- a/libguile/filesys.c
+++ b/libguile/filesys.c
@@ -1045,6 +1045,29 @@ SCM_DEFINE (scm_symlink, "symlink", 2, 0, 0,
#undef FUNC_NAME
#endif /* HAVE_SYMLINK */
+#ifdef HAVE_SYMLINKAT
+SCM_DEFINE (scm_symlinkat, "symlinkat", 3, 0, 0,
+ (SCM dir, SCM oldpath, SCM newpath),
+ "Like @code{symlink}, but resolve @var{newpath} relative\n"
+ "to the directory referred to by the file port @var{dir}.")
+#define FUNC_NAME s_scm_symlinkat
+{
+ int val;
+ int fdes;
+
+ SCM_VALIDATE_OPFPORT (SCM_ARG1, dir);
+ fdes = SCM_FPORT_FDES (dir);
+ STRING2_SYSCALL (oldpath, c_oldpath,
+ newpath, c_newpath,
+ val = symlinkat (c_oldpath, fdes, c_newpath));
+ scm_remember_upto_here_1 (dir);
+ if (val != 0)
+ SCM_SYSERROR;
+ return SCM_UNSPECIFIED;
+}
+#undef FUNC_NAME
+#endif /* HAVE_SYMLINKAT */
+
/* Static helper function for choosing between readlink
and readlinkat. */
static int
diff --git a/libguile/filesys.h b/libguile/filesys.h
index a3b257c12..d181aca52 100644
--- a/libguile/filesys.h
+++ b/libguile/filesys.h
@@ -62,6 +62,7 @@ SCM_API SCM scm_select (SCM reads, SCM writes, SCM excepts, SCM secs, SCM msecs)
SCM_API SCM scm_fcntl (SCM object, SCM cmd, SCM value);
SCM_API SCM scm_fsync (SCM object);
SCM_API SCM scm_symlink (SCM oldpath, SCM newpath);
+SCM_API SCM scm_symlinkat (SCM dir, SCM oldpath, SCM newpath);
SCM_API SCM scm_readlink (SCM path);
SCM_API SCM scm_lstat (SCM str);
SCM_API SCM scm_copy_file (SCM oldfile, SCM newfile);
diff --git a/test-suite/tests/filesys.test b/test-suite/tests/filesys.test
index 7feb3492f..64bf92333 100644
--- a/test-suite/tests/filesys.test
+++ b/test-suite/tests/filesys.test
@@ -367,3 +367,30 @@
(false-if-exception (delete-file (test-symlink)))
(false-if-exception (delete-file (test-file))))
+
+(with-test-prefix "symlinkat"
+ (pass-if-equal "create" (test-file)
+ (unless (defined? 'symlinkat)
+ (throw 'unsupported))
+ (call-with-port
+ (open "." O_RDONLY)
+ (lambda (port)
+ (symlinkat port (test-file) (test-symlink))
+ (readlink (test-symlink)))))
+ (false-if-exception (delete-file (test-symlink)))
+
+ (pass-if-exception "not a port" exception:wrong-type-arg
+ (unless (defined? 'symlinkat)
+ (throw 'unsupported))
+ (symlinkat "bogus" (test-file) (test-symlink)))
+
+ (pass-if-exception "not a file port" exception:wrong-type-arg
+ (unless (defined? 'symlinkat)
+ (throw 'unsupported))
+ (symlinkat (open-input-string "") (test-file) (test-symlink)))
+
+ (pass-if-exception "closed port" exception:wrong-type-arg
+ (unless (defined? 'symlinkat)
+ (throw 'unsupported))
+ (symlinkat (call-with-port (open "." O_RDONLY) identity)
+ (test-file) (test-symlink))))
--
2.30.2