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-rw-r--r--include/unistd.h61
1 files changed, 60 insertions, 1 deletions
diff --git a/include/unistd.h b/include/unistd.h
index c45e425..9a5f612 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -73,13 +73,72 @@
#define STDERR_FILENO 2
-/* TODO temporary values */
+/**
+ * Used in `access` and `faccessat`, to check
+ * weather a file appears to exists for the
+ * current user. It is impled for `X_OK`,
+ * `W_OK` and `R_OK`.
+ *
+ * Its value, 0, comes from that this check
+ * is always performed.
+ *
+ * @etymology This constant is named in symmetry with
+ * `X_OK`, `W_OK`, and `R_OK`. The 'F' comes
+ * from "(f)ile exists", and '_OK' comes
+ * from the name of the other '?(_OK)'
+ * constants.
+ *
+ * @since Always.
+ */
#define F_OK 0
+
+/**
+ * Used in `access` and `faccessat`, to check
+ * weather a file is executable (for directories:
+ * its content can be listed) for the current
+ * user. Implies `F_OK`.
+ *
+ * Its value, 1, comes from that for each user-octet
+ * in the permission bits, the bit 1 signifies that
+ * the file is executable.
+ *
+ * @etymology Is e(x)ecute (ok)ay?
+ *
+ * @since Always.
+ */
#define X_OK 1
+
+/**
+ * Used in `access` and `faccessat`, to check
+ * weather a file is writable for the current
+ * user. Implies `F_OK`.
+ *
+ * Its value, 2, comes from that for each user-octet
+ * in the permission bits, the bit 2 signifies that
+ * the file is writable.
+ *
+ * @since Always.
+ * @etymology Is (w)rite (ok)ay?
+ */
#define W_OK 2
+
+/**
+ * Used in `access` and `faccessat`, to check
+ * weather a file is readable for the current
+ * user. Implies `F_OK`.
+ *
+ * Its value, 4, comes from that for each user-octet
+ * in the permission bits, the bit 4 signifies that
+ * the file is readable.
+ *
+ * @etymology Is (r)ead (ok)ay?
+ *
+ * @since Always.
+ */
#define R_OK 4
+
/**
* Set the high end of the calling process's
* data segment.