Add readlink and readmagiclink functions

Signed-off-by: Mattias Andrée <maandree@kth.se>

14 files changed, 383 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index e1401b8..d44d559 100644
--- a/Makefile
+++ b/Makefile
@@ -411,6 +411,7 @@ OBJ =\
 	ealigned_wmemdup.o\
 	ecalloc.o\
 	ecallocn.o\
+	efreadlink.o\
 	egetcwd.o\
 	egmtime.o\
 	elocaltime.o\
@@ -440,6 +441,7 @@ OBJ =\
 	enaligned_wmemdup.o\
 	encalloc.o\
 	encallocn.o\
+	enfreadlink.o\
 	engetcwd.o\
 	engmtime.o\
 	enlocaltime.o\
@@ -463,6 +465,9 @@ OBJ =\
 	enpvallocn.o\
 	enpvallocz.o\
 	enpvalloczn.o\
+	enreadlink.o\
+	enreadlinkat.o\
+	enreadmagiclink.o\
 	enrealloc.o\
 	enreallocarray.o\
 	enreallocn.o\
@@ -502,6 +507,9 @@ OBJ =\
 	epvallocn.o\
 	epvallocz.o\
 	epvalloczn.o\
+	ereadlink.o\
+	ereadlinkat.o\
+	ereadmagiclink.o\
 	erealloc.o\
 	ereallocarray.o\
 	ereallocn.o\
@@ -540,6 +548,7 @@ OBJ =\
 	fexecl.o\
 	fexecle.o\
 	fexecv.o\
+	freadlink.o\
 	generate_seed.o\
 	getcwd.o\
 	getenv_e.o\
@@ -943,6 +952,9 @@ OBJ =\
 	rawmemrchr_inv.o\
 	rawmemrelem.o\
 	rawmemrelem_inv.o\
+	readlink.o\
+	readlinkat.o\
+	readmagiclink.o\
 	reallocarray.o\
 	reallocarrayf.o\
 	reallocf.o\
diff --git a/efreadlink.c b/efreadlink.c
new file mode 100644
index 0000000..a76c411
--- /dev/null
+++ b/efreadlink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_efreadlink(int);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/enfreadlink.c b/enfreadlink.c
new file mode 100644
index 0000000..9f6a055
--- /dev/null
+++ b/enfreadlink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_enfreadlink(int, int);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/enreadlink.c b/enreadlink.c
new file mode 100644
index 0000000..669e1fd
--- /dev/null
+++ b/enreadlink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_enreadlink(int, const char *);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/enreadlinkat.c b/enreadlinkat.c
new file mode 100644
index 0000000..74b4562
--- /dev/null
+++ b/enreadlinkat.c
@@ -0,0 +1,29 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+char *
+libsimple_enreadlinkat(int status, int dirfd, const char *path)
+{
+	char *ret = libsimple_readlinkat(dirfd, path);
+	if (!ret) {
+		if (dirfd == AT_FDCWD)
+			libsimple_enprintf(status, "libsimple_readlinkat AT_FDCWD %s:", path);
+		else
+			libsimple_enprintf(status, "libsimple_readlinkat %i %s:", dirfd, path);
+	}
+	return ret;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/enreadmagiclink.c b/enreadmagiclink.c
new file mode 100644
index 0000000..a4a99a4
--- /dev/null
+++ b/enreadmagiclink.c
@@ -0,0 +1,25 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+char *
+libsimple_enreadmagiclink(int status, const char *path)
+{
+	char *ret = libsimple_readmagiclink(path);
+	if (!ret)
+		libsimple_enprintf(status, "libsimple_readmagiclinkat %s:", path);
+	return ret;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/ereadlink.c b/ereadlink.c
new file mode 100644
index 0000000..3b990e4
--- /dev/null
+++ b/ereadlink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_ereadlink(const char *);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/ereadlinkat.c b/ereadlinkat.c
new file mode 100644
index 0000000..7294ade
--- /dev/null
+++ b/ereadlinkat.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_ereadlinkat(int, const char *);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/ereadmagiclink.c b/ereadmagiclink.c
new file mode 100644
index 0000000..396e618
--- /dev/null
+++ b/ereadmagiclink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_ereadmagiclink(const char *);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/freadlink.c b/freadlink.c
new file mode 100644
index 0000000..90f5380
--- /dev/null
+++ b/freadlink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_freadlink(int);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/libsimple/path.h b/libsimple/path.h
index 65f2751..6f2a8b8 100644
--- a/libsimple/path.h
+++ b/libsimple/path.h
@@ -68,3 +68,74 @@ libsimple_eabspath(const char *p__, const char *r__) /* TODO man */
 {
 	return libsimple_enabspath(libsimple_default_failure_exit, p__, r__);
 }
+
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__)))
+char *libsimple_readlinkat(int, const char *); /* TODO man, doc */
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+char *libsimple_enreadlinkat(int, int, const char *); /* TODO man, doc */
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+inline char *
+libsimple_ereadlinkat(int dirfd__, const char *path__) /* TODO man, doc */
+{
+	return libsimple_enreadlinkat(libsimple_default_failure_exit, dirfd__, path__);
+}
+
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__)))
+inline char *
+libsimple_readlink(const char *path__) /* TODO man, doc */
+{
+	return libsimple_readlinkat(AT_FDCWD, path__);
+}
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+inline char *
+libsimple_enreadlink(int status__, const char *path__) /* TODO man, doc */
+{
+	return libsimple_enreadlinkat(status__, AT_FDCWD, path__);
+}
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+inline char *
+libsimple_ereadlink(const char *path__) /* TODO man, doc */
+{
+	return libsimple_enreadlinkat(libsimple_default_failure_exit, AT_FDCWD, path__);
+}
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__)))
+inline char *
+libsimple_freadlink(int fd__) /* TODO man, doc */
+{
+	return libsimple_readlinkat(fd__, "");
+}
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+inline char *
+libsimple_enfreadlink(int status__, int fd__) /* TODO man, doc */
+{
+	return libsimple_enreadlinkat(status__, fd__, "");
+}
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+inline char *
+libsimple_efreadlink(int fd__) /* TODO man, doc */
+{
+	return libsimple_enreadlinkat(libsimple_default_failure_exit, fd__, "");
+}
+
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__)))
+char *libsimple_readmagiclink(const char *); /* TODO man, doc */
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+char *libsimple_enreadmagiclink(int, const char *); /* TODO man, doc */
+
+LIBSIMPLE_GCC_ONLY__(__attribute__((__malloc__, __assume_aligned__(1), __warn_unused_result__, __nonnull__, __returns_nonnull__)))
+inline char *
+libsimple_ereadmagiclink(const char *path__) /* TODO man, doc */
+{
+	return libsimple_enreadmagiclink(libsimple_default_failure_exit, path__);
+}
diff --git a/readlink.c b/readlink.c
new file mode 100644
index 0000000..2bd9ffb
--- /dev/null
+++ b/readlink.c
@@ -0,0 +1,18 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+extern inline char *libsimple_readlink(const char *);
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/readlinkat.c b/readlinkat.c
new file mode 100644
index 0000000..2ec5e88
--- /dev/null
+++ b/readlinkat.c
@@ -0,0 +1,41 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+char *
+libsimple_readlinkat(int dirfd, const char *path)
+{
+	char *ret = NULL, *new;
+	size_t size = 0;
+	ssize_t r;
+
+	do {
+		new = realloc(ret, size += 128);
+		if (!new) {
+			errno = ENOMEM;
+		fail:
+			free(ret);
+			return NULL;
+		}
+		ret = new;
+		r = readlinkat(dirfd, path, ret, size - 1U);
+		if (r < 0)
+			goto fail;
+	} while ((size_t)r >= size - 2U);
+
+	ret[r] = '\0';
+	return ret;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif
diff --git a/readmagiclink.c b/readmagiclink.c
new file mode 100644
index 0000000..160dd96
--- /dev/null
+++ b/readmagiclink.c
@@ -0,0 +1,61 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+char *
+libsimple_readmagiclink(const char *path)
+{
+	int fd;
+	struct stat st;
+	char *target1;
+	char *target2;
+
+	fd = open(path, O_PATH | O_NOFOLLOW);
+	if (fd < 0)
+		return NULL;
+
+	target1 = libsimple_efreadlink(fd);
+	if (!strends(target1, " (deleted)")) {
+		close(fd);
+		return target1;
+	}
+
+	if (fstat(fd, &st)) {
+		free(target1);
+		close(fd);
+		return NULL;
+	}
+
+	target2 = libsimple_efreadlink(fd);
+	if (!strends(target2, " (deleted)")) {
+		free(target1);
+		close(fd);
+		return target2;
+	}
+
+	close(fd);
+
+	if (strcmp(target1, target2)) {
+		free(target2);
+		return target1;
+	} else {
+		free(target1);
+		if (st.st_nlink)
+			return target2;
+		target2[strlen(target2) - (sizeof(" (deleted)") - 1U)] = '\0';
+		return target2;
+	}
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void) /* TODO test */
+{
+	return 0;
+}
+
+#endif