merge POSIX.1-1988/1990

1 files changed, 43 insertions, 0 deletions

diff --git a/src/unistd/access.c b/src/unistd/access.c
new file mode 100644
index 00000000..25554edf
--- /dev/null
+++ b/src/unistd/access.c
@@ -0,0 +1,43 @@
+#include "stddef.h"
+#include "sys/types.h"
+#include <unistd.h>
+#include "errno.h"
+#include "sys/stat.h"
+
+int access(const char *path, int amode)
+{
+	struct stat st;
+	mode_t check = (amode & R_OK ? 4 : 0)
+		| (amode & W_OK ? 2 : 0)
+		| (amode & X_OK ? 1 : 0);
+
+	if (amode != F_OK && ((amode & ~(R_OK | W_OK | X_OK)) != 0)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (stat(path, &st) == -1) {
+		/* errno set by stat() */
+		return -1;
+	}
+
+	if (amode == F_OK) {
+		return 0;
+	}
+
+	if (st.st_uid == getuid()) {
+		check <<= 6;
+	} else if (st.st_gid == getgid()) {
+		check <<= 3;
+	}
+
+	if ((st.st_mode & check) == check) {
+		return 0;
+	}
+
+	errno = EACCES;
+	return -1;
+}
+/*
+POSIX(1)
+*/